DynamoDB examples using Amazon CLI with Bash script - Amazon Command Line Interface
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

DynamoDB examples using Amazon CLI with Bash script

The following code examples show you how to perform actions and implement common scenarios by using the Amazon Command Line Interface with Bash script with DynamoDB.

Actions are code excerpts from larger programs and must be run in context. While actions show you how to call individual service functions, you can see actions in context in their related scenarios and cross-service examples.

Scenarios are code examples that show you how to accomplish a specific task by calling multiple functions within the same service.

Each example includes a link to GitHub, where you can find instructions on how to set up and run the code in context.

Actions

The following code example shows how to create a DynamoDB table.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################### # function dynamodb_create_table # # This function creates an Amazon DynamoDB table. # # Parameters: # -n table_name -- The name of the table to create. # -a attribute_definitions -- JSON file path of a list of attributes and their types. # -k key_schema -- JSON file path of a list of attributes and their key types. # -p provisioned_throughput -- Provisioned throughput settings for the table. # # Returns: # 0 - If successful. # 1 - If it fails. ############################################################################### function dynamodb_create_table() { local table_name attribute_definitions key_schema provisioned_throughput response local option OPTARG # Required to use getopts command in a function. ####################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_create_table" echo "Creates an Amazon DynamoDB table." echo " -n table_name -- The name of the table to create." echo " -a attribute_definitions -- JSON file path of a list of attributes and their types." echo " -k key_schema -- JSON file path of a list of attributes and their key types." echo " -p provisioned_throughput -- Provisioned throughput settings for the table." echo "" } # Retrieve the calling parameters. while getopts "n:a:k:p:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; a) attribute_definitions="${OPTARG}" ;; k) key_schema="${OPTARG}" ;; p) provisioned_throughput="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$attribute_definitions" ]]; then errecho "ERROR: You must provide an attribute definitions json file path the -a parameter." usage return 1 fi if [[ -z "$key_schema" ]]; then errecho "ERROR: You must provide a key schema json file path the -k parameter." usage return 1 fi if [[ -z "$provisioned_throughput" ]]; then errecho "ERROR: You must provide a provisioned throughput json file path the -p parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho " attribute_definitions: $attribute_definitions" iecho " key_schema: $key_schema" iecho " provisioned_throughput: $provisioned_throughput" iecho "" response=$(aws dynamodb create-table \ --table-name "$table_name" \ --attribute-definitions file://"$attribute_definitions" \ --key-schema file://"$key_schema" \ --provisioned-throughput "$provisioned_throughput") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports create-table operation failed.$response" return 1 fi return 0 }

The utility functions used in this example.

############################################################################### # function iecho # # This function enables the script to display the specified text only if # the global variable $VERBOSE is set to true. ############################################################################### function iecho() { if [[ $VERBOSE == true ]]; then echo "$@" fi } ############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see CreateTable in Amazon CLI Command Reference.

The following code example shows how to delete a DynamoDB table.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################### # function dynamodb_delete_table # # This function deletes a DynamoDB table. # # Parameters: # -n table_name -- The name of the table to delete. # # Returns: # 0 - If successful. # 1 - If it fails. ############################################################################### function dynamodb_delete_table() { local table_name response local option OPTARG # Required to use getopts command in a function. # bashsupport disable=BP5008 function usage() { echo "function dynamodb_delete_table" echo "Deletes an Amazon DynamoDB table." echo " -n table_name -- The name of the table to delete." echo "" } # Retrieve the calling parameters. while getopts "n:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho "" response=$(aws dynamodb delete-table \ --table-name "$table_name") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports delete-table operation failed.$response" return 1 fi return 0 }

The utility functions used in this example.

############################################################################### # function iecho # # This function enables the script to display the specified text only if # the global variable $VERBOSE is set to true. ############################################################################### function iecho() { if [[ $VERBOSE == true ]]; then echo "$@" fi } ############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see DeleteTable in Amazon CLI Command Reference.

The following code example shows how to delete an item from a DynamoDB table.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################## # function dynamodb_delete_item # # This function deletes an item from a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # -k keys -- Path to json file containing the keys that identify the item to delete. # # Returns: # 0 - If successful. # 1 - If it fails. ########################################################################### function dynamodb_delete_item() { local table_name keys response local option OPTARG # Required to use getopts command in a function. # ###################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_delete_item" echo "Delete an item from a DynamoDB table." echo " -n table_name -- The name of the table." echo " -k keys -- Path to json file containing the keys that identify the item to delete." echo "" } while getopts "n:k:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; k) keys="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$keys" ]]; then errecho "ERROR: You must provide a keys json file path the -k parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho " keys: $keys" iecho "" response=$(aws dynamodb delete-item \ --table-name "$table_name" \ --key file://"$keys") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports delete-item operation failed.$response" return 1 fi return 0 }

The utility functions used in this example.

############################################################################### # function iecho # # This function enables the script to display the specified text only if # the global variable $VERBOSE is set to true. ############################################################################### function iecho() { if [[ $VERBOSE == true ]]; then echo "$@" fi } ############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see DeleteItem in Amazon CLI Command Reference.

The following code example shows how to get a batch of DynamoDB items.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################# # function dynamodb_batch_get_item # # This function gets a batch of items from a DynamoDB table. # # Parameters: # -i item -- Path to json file containing the keys of the items to get. # # Returns: # The items as json output. # And: # 0 - If successful. # 1 - If it fails. ########################################################################## function dynamodb_batch_get_item() { local item response local option OPTARG # Required to use getopts command in a function. ####################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_batch_get_item" echo "Get a batch of items from a DynamoDB table." echo " -i item -- Path to json file containing the keys of the items to get." echo "" } while getopts "i:h" option; do case "${option}" in i) item="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$item" ]]; then errecho "ERROR: You must provide an item with the -i parameter." usage return 1 fi response=$(aws dynamodb batch-get-item \ --request-items file://"$item") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports batch-get-item operation failed.$response" return 1 fi echo "$response" return 0 }

The utility functions used in this example.

############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see BatchGetItem in Amazon CLI Command Reference.

The following code example shows how to get an item from a DynamoDB table.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################# # function dynamodb_get_item # # This function gets an item from a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # -k keys -- Path to json file containing the keys that identify the item to get. # [-q query] -- Optional JMESPath query expression. # # Returns: # The item as text output. # And: # 0 - If successful. # 1 - If it fails. ############################################################################ function dynamodb_get_item() { local table_name keys query response local option OPTARG # Required to use getopts command in a function. # ###################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_get_item" echo "Get an item from a DynamoDB table." echo " -n table_name -- The name of the table." echo " -k keys -- Path to json file containing the keys that identify the item to get." echo " [-q query] -- Optional JMESPath query expression." echo "" } query="" while getopts "n:k:q:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; k) keys="${OPTARG}" ;; q) query="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$keys" ]]; then errecho "ERROR: You must provide a keys json file path the -k parameter." usage return 1 fi if [[ -n "$query" ]]; then response=$(aws dynamodb get-item \ --table-name "$table_name" \ --key file://"$keys" \ --output text \ --query "$query") else response=$( aws dynamodb get-item \ --table-name "$table_name" \ --key file://"$keys" \ --output text ) fi local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports get-item operation failed.$response" return 1 fi if [[ -n "$query" ]]; then echo "$response" | sed "/^\t/s/\t//1" # Remove initial tab that the JMSEPath query inserts on some strings. else echo "$response" fi return 0 }

The utility functions used in this example.

############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see GetItem in Amazon CLI Command Reference.

The following code example shows how to get information about a DynamoDB table.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################### # function dynamodb_describe_table # # This function returns the status of a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # # Response: # - TableStatus: # And: # 0 - Table is active. # 1 - If it fails. ############################################################################### function dynamodb_describe_table { local table_name local option OPTARG # Required to use getopts command in a function. ####################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_describe_table" echo "Describe the status of a DynamoDB table." echo " -n table_name -- The name of the table." echo "" } # Retrieve the calling parameters. while getopts "n:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi local table_status table_status=$( aws dynamodb describe-table \ --table-name "$table_name" \ --output text \ --query 'Table.TableStatus' ) local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log "$error_code" errecho "ERROR: AWS reports describe-table operation failed.$table_status" return 1 fi echo "$table_status" return 0 }

The utility functions used in this example.

############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see DescribeTable in Amazon CLI Command Reference.

The following code example shows how to list DynamoDB tables.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################## # function dynamodb_list_tables # # This function lists all the tables in a DynamoDB. # # Returns: # 0 - If successful. # 1 - If it fails. ########################################################################### function dynamodb_list_tables() { response=$(aws dynamodb list-tables \ --output text \ --query "TableNames") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports batch-write-item operation failed.$response" return 1 fi echo "$response" | tr -s "[:space:]" "\n" return 0 }

The utility functions used in this example.

############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see ListTables in Amazon CLI Command Reference.

The following code example shows how to put an item in a DynamoDB table.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################## # function dynamodb_put_item # # This function puts an item into a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # -i item -- Path to json file containing the item values. # # Returns: # 0 - If successful. # 1 - If it fails. ############################################################################## function dynamodb_put_item() { local table_name item response local option OPTARG # Required to use getopts command in a function. ####################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_put_item" echo "Put an item into a DynamoDB table." echo " -n table_name -- The name of the table." echo " -i item -- Path to json file containing the item values." echo "" } while getopts "n:i:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; i) item="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$item" ]]; then errecho "ERROR: You must provide an item with the -i parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho " item: $item" iecho "" iecho "" response=$(aws dynamodb put-item \ --table-name "$table_name" \ --item file://"$item") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports put-item operation failed.$response" return 1 fi return 0 }

The utility functions used in this example.

############################################################################### # function iecho # # This function enables the script to display the specified text only if # the global variable $VERBOSE is set to true. ############################################################################### function iecho() { if [[ $VERBOSE == true ]]; then echo "$@" fi } ############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see PutItem in Amazon CLI Command Reference.

The following code example shows how to query a DynamoDB table.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################# # function dynamodb_query # # This function queries a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # -k key_condition_expression -- The key condition expression. # -a attribute_names -- Path to JSON file containing the attribute names. # -v attribute_values -- Path to JSON file containing the attribute values. # [-p projection_expression] -- Optional projection expression. # # Returns: # The items as json output. # And: # 0 - If successful. # 1 - If it fails. ########################################################################### function dynamodb_query() { local table_name key_condition_expression attribute_names attribute_values projection_expression response local option OPTARG # Required to use getopts command in a function. # ###################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_query" echo "Query a DynamoDB table." echo " -n table_name -- The name of the table." echo " -k key_condition_expression -- The key condition expression." echo " -a attribute_names -- Path to JSON file containing the attribute names." echo " -v attribute_values -- Path to JSON file containing the attribute values." echo " [-p projection_expression] -- Optional projection expression." echo "" } while getopts "n:k:a:v:p:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; k) key_condition_expression="${OPTARG}" ;; a) attribute_names="${OPTARG}" ;; v) attribute_values="${OPTARG}" ;; p) projection_expression="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$key_condition_expression" ]]; then errecho "ERROR: You must provide a key condition expression with the -k parameter." usage return 1 fi if [[ -z "$attribute_names" ]]; then errecho "ERROR: You must provide a attribute names with the -a parameter." usage return 1 fi if [[ -z "$attribute_values" ]]; then errecho "ERROR: You must provide a attribute values with the -v parameter." usage return 1 fi if [[ -z "$projection_expression" ]]; then response=$(aws dynamodb query \ --table-name "$table_name" \ --key-condition-expression "$key_condition_expression" \ --expression-attribute-names file://"$attribute_names" \ --expression-attribute-values file://"$attribute_values") else response=$(aws dynamodb query \ --table-name "$table_name" \ --key-condition-expression "$key_condition_expression" \ --expression-attribute-names file://"$attribute_names" \ --expression-attribute-values file://"$attribute_values" \ --projection-expression "$projection_expression") fi local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports query operation failed.$response" return 1 fi echo "$response" return 0 }

The utility functions used in this example.

############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see Query in Amazon CLI Command Reference.

The following code example shows how to scan a DynamoDB table.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################# # function dynamodb_scan # # This function scans a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # -f filter_expression -- The filter expression. # -a expression_attribute_names -- Path to JSON file containing the expression attribute names. # -v expression_attribute_values -- Path to JSON file containing the expression attribute values. # [-p projection_expression] -- Optional projection expression. # # Returns: # The items as json output. # And: # 0 - If successful. # 1 - If it fails. ########################################################################### function dynamodb_scan() { local table_name filter_expression expression_attribute_names expression_attribute_values projection_expression response local option OPTARG # Required to use getopts command in a function. # ###################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_scan" echo "Scan a DynamoDB table." echo " -n table_name -- The name of the table." echo " -f filter_expression -- The filter expression." echo " -a expression_attribute_names -- Path to JSON file containing the expression attribute names." echo " -v expression_attribute_values -- Path to JSON file containing the expression attribute values." echo " [-p projection_expression] -- Optional projection expression." echo "" } while getopts "n:f:a:v:p:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; f) filter_expression="${OPTARG}" ;; a) expression_attribute_names="${OPTARG}" ;; v) expression_attribute_values="${OPTARG}" ;; p) projection_expression="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$filter_expression" ]]; then errecho "ERROR: You must provide a filter expression with the -f parameter." usage return 1 fi if [[ -z "$expression_attribute_names" ]]; then errecho "ERROR: You must provide expression attribute names with the -a parameter." usage return 1 fi if [[ -z "$expression_attribute_values" ]]; then errecho "ERROR: You must provide expression attribute values with the -v parameter." usage return 1 fi if [[ -z "$projection_expression" ]]; then response=$(aws dynamodb scan \ --table-name "$table_name" \ --filter-expression "$filter_expression" \ --expression-attribute-names file://"$expression_attribute_names" \ --expression-attribute-values file://"$expression_attribute_values") else response=$(aws dynamodb scan \ --table-name "$table_name" \ --filter-expression "$filter_expression" \ --expression-attribute-names file://"$expression_attribute_names" \ --expression-attribute-values file://"$expression_attribute_values" \ --projection-expression "$projection_expression") fi local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports scan operation failed.$response" return 1 fi echo "$response" return 0 }

The utility functions used in this example.

############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see Scan in Amazon CLI Command Reference.

The following code example shows how to update an item in a DynamoDB table.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################## # function dynamodb_update_item # # This function updates an item in a DynamoDB table. # # # Parameters: # -n table_name -- The name of the table. # -k keys -- Path to json file containing the keys that identify the item to update. # -e update expression -- An expression that defines one or more attributes to be updated. # -v values -- Path to json file containing the update values. # # Returns: # 0 - If successful. # 1 - If it fails. ############################################################################# function dynamodb_update_item() { local table_name keys update_expression values response local option OPTARG # Required to use getopts command in a function. ####################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_update_item" echo "Update an item in a DynamoDB table." echo " -n table_name -- The name of the table." echo " -k keys -- Path to json file containing the keys that identify the item to update." echo " -e update expression -- An expression that defines one or more attributes to be updated." echo " -v values -- Path to json file containing the update values." echo "" } while getopts "n:k:e:v:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; k) keys="${OPTARG}" ;; e) update_expression="${OPTARG}" ;; v) values="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$keys" ]]; then errecho "ERROR: You must provide a keys json file path the -k parameter." usage return 1 fi if [[ -z "$update_expression" ]]; then errecho "ERROR: You must provide an update expression with the -e parameter." usage return 1 fi if [[ -z "$values" ]]; then errecho "ERROR: You must provide a values json file path the -v parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho " keys: $keys" iecho " update_expression: $update_expression" iecho " values: $values" response=$(aws dynamodb update-item \ --table-name "$table_name" \ --key file://"$keys" \ --update-expression "$update_expression" \ --expression-attribute-values file://"$values") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports update-item operation failed.$response" return 1 fi return 0 }

The utility functions used in this example.

############################################################################### # function iecho # # This function enables the script to display the specified text only if # the global variable $VERBOSE is set to true. ############################################################################### function iecho() { if [[ $VERBOSE == true ]]; then echo "$@" fi } ############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see UpdateItem in Amazon CLI Command Reference.

The following code example shows how to write a batch of DynamoDB items.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

############################################################################## # function dynamodb_batch_write_item # # This function writes a batch of items into a DynamoDB table. # # Parameters: # -i item -- Path to json file containing the items to write. # # Returns: # 0 - If successful. # 1 - If it fails. ############################################################################ function dynamodb_batch_write_item() { local item response local option OPTARG # Required to use getopts command in a function. ####################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_batch_write_item" echo "Write a batch of items into a DynamoDB table." echo " -i item -- Path to json file containing the items to write." echo "" } while getopts "i:h" option; do case "${option}" in i) item="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$item" ]]; then errecho "ERROR: You must provide an item with the -i parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho " item: $item" iecho "" response=$(aws dynamodb batch-write-item \ --request-items file://"$item") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports batch-write-item operation failed.$response" return 1 fi return 0 }

The utility functions used in this example.

############################################################################### # function iecho # # This function enables the script to display the specified text only if # the global variable $VERBOSE is set to true. ############################################################################### function iecho() { if [[ $VERBOSE == true ]]; then echo "$@" fi } ############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }
  • For API details, see BatchWriteItem in Amazon CLI Command Reference.

Scenarios

The following code example shows how to:

  • Create a table that can hold movie data.

  • Put, get, and update a single movie in the table.

  • Write movie data to the table from a sample JSON file.

  • Query for movies that were released in a given year.

  • Scan for movies that were released in a range of years.

  • Delete a movie from the table, then delete the table.

Amazon CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Amazon Code Examples Repository.

The DynamoDB getting started scenario.

############################################################################### # function dynamodb_getting_started_movies # # Scenario to create an Amazon DynamoDB table and perform a series of operations on the table. # # Returns: # 0 - If successful. # 1 - If an error occurred. ############################################################################### function dynamodb_getting_started_movies() { source ./dynamodb_operations.sh key_schema_json_file="dynamodb_key_schema.json" attribute_definitions_json_file="dynamodb_attr_def.json" item_json_file="movie_item.json" key_json_file="movie_key.json" batch_json_file="batch.json" attribute_names_json_file="attribute_names.json" attributes_values_json_file="attribute_values.json" echo_repeat "*" 88 echo echo "Welcome to the Amazon DynamoDB getting started demo." echo echo_repeat "*" 88 echo local table_name echo -n "Enter a name for a new DynamoDB table: " get_input table_name=$get_input_result local provisioned_throughput="ReadCapacityUnits=5,WriteCapacityUnits=5" echo '[ {"AttributeName": "year", "KeyType": "HASH"}, {"AttributeName": "title", "KeyType": "RANGE"} ]' >"$key_schema_json_file" echo '[ {"AttributeName": "year", "AttributeType": "N"}, {"AttributeName": "title", "AttributeType": "S"} ]' >"$attribute_definitions_json_file" if dynamodb_create_table -n "$table_name" -a "$attribute_definitions_json_file" \ -k "$key_schema_json_file" -p "$provisioned_throughput" 1>/dev/null; then echo "Created a DynamoDB table named $table_name" else errecho "The table failed to create. This demo will exit." clean_up return 1 fi echo "Waiting for the table to become active...." if dynamodb_wait_table_active -n "$table_name"; then echo "The table is now active." else errecho "The table failed to become active. This demo will exit." cleanup "$table_name" return 1 fi echo echo_repeat "*" 88 echo echo -n "Enter the title of a movie you want to add to the table: " get_input local added_title added_title=$get_input_result local added_year get_int_input "What year was it released? " added_year=$get_input_result local rating get_float_input "On a scale of 1 - 10, how do you rate it? " "1" "10" rating=$get_input_result local plot echo -n "Summarize the plot for me: " get_input plot=$get_input_result echo '{ "year": {"N" :"'"$added_year"'"}, "title": {"S" : "'"$added_title"'"}, "info": {"M" : {"plot": {"S" : "'"$plot"'"}, "rating": {"N" :"'"$rating"'"} } } }' >"$item_json_file" if dynamodb_put_item -n "$table_name" -i "$item_json_file"; then echo "The movie '$added_title' was successfully added to the table '$table_name'." else errecho "Put item failed. This demo will exit." clean_up "$table_name" return 1 fi echo echo_repeat "*" 88 echo echo "Let's update your movie '$added_title'." get_float_input "You rated it $rating, what new rating would you give it? " "1" "10" rating=$get_input_result echo -n "You summarized the plot as '$plot'." echo "What would you say now? " get_input plot=$get_input_result echo '{ "year": {"N" :"'"$added_year"'"}, "title": {"S" : "'"$added_title"'"} }' >"$key_json_file" echo '{ ":r": {"N" :"'"$rating"'"}, ":p": {"S" : "'"$plot"'"} }' >"$item_json_file" local update_expression="SET info.rating = :r, info.plot = :p" if dynamodb_update_item -n "$table_name" -k "$key_json_file" -e "$update_expression" -v "$item_json_file"; then echo "Updated '$added_title' with new attributes." else errecho "Update item failed. This demo will exit." clean_up "$table_name" return 1 fi echo echo_repeat "*" 88 echo echo "We will now use batch write to upload 150 movie entries into the table." local batch_json for batch_json in movie_files/movies_*.json; do echo "{ \"$table_name\" : $(<"$batch_json") }" >"$batch_json_file" if dynamodb_batch_write_item -i "$batch_json_file" 1>/dev/null; then echo "Entries in $batch_json added to table." else errecho "Batch write failed. This demo will exit." clean_up "$table_name" return 1 fi done local title="The Lord of the Rings: The Fellowship of the Ring" local year="2001" if get_yes_no_input "Let's move on...do you want to get info about '$title'? (y/n) "; then echo '{ "year": {"N" :"'"$year"'"}, "title": {"S" : "'"$title"'"} }' >"$key_json_file" local info info=$(dynamodb_get_item -n "$table_name" -k "$key_json_file") # shellcheck disable=SC2181 if [[ ${?} -ne 0 ]]; then errecho "Get item failed. This demo will exit." clean_up "$table_name" return 1 fi echo "Here is what I found:" echo "$info" fi local ask_for_year=true while [[ "$ask_for_year" == true ]]; do echo "Let's get a list of movies released in a given year." get_int_input "Enter a year between 1972 and 2018: " "1972" "2018" year=$get_input_result echo '{ "#n": "year" }' >"$attribute_names_json_file" echo '{ ":v": {"N" :"'"$year"'"} }' >"$attributes_values_json_file" response=$(dynamodb_query -n "$table_name" -k "#n=:v" -a "$attribute_names_json_file" -v "$attributes_values_json_file") # shellcheck disable=SC2181 if [[ ${?} -ne 0 ]]; then errecho "Query table failed. This demo will exit." clean_up "$table_name" return 1 fi echo "Here is what I found:" echo "$response" if ! get_yes_no_input "Try another year? (y/n) "; then ask_for_year=false fi done echo "Now let's scan for movies released in a range of years. Enter a year: " get_int_input "Enter a year between 1972 and 2018: " "1972" "2018" local start=$get_input_result get_int_input "Enter another year: " "1972" "2018" local end=$get_input_result echo '{ "#n": "year" }' >"$attribute_names_json_file" echo '{ ":v1": {"N" : "'"$start"'"}, ":v2": {"N" : "'"$end"'"} }' >"$attributes_values_json_file" response=$(dynamodb_scan -n "$table_name" -f "#n BETWEEN :v1 AND :v2" -a "$attribute_names_json_file" -v "$attributes_values_json_file") # shellcheck disable=SC2181 if [[ ${?} -ne 0 ]]; then errecho "Scan table failed. This demo will exit." clean_up "$table_name" return 1 fi echo "Here is what I found:" echo "$response" echo echo_repeat "*" 88 echo echo "Let's remove your movie '$added_title' from the table." if get_yes_no_input "Do you want to remove '$added_title'? (y/n) "; then echo '{ "year": {"N" :"'"$added_year"'"}, "title": {"S" : "'"$added_title"'"} }' >"$key_json_file" if ! dynamodb_delete_item -n "$table_name" -k "$key_json_file"; then errecho "Delete item failed. This demo will exit." clean_up "$table_name" return 1 fi fi if get_yes_no_input "Do you want to delete the table '$table_name'? (y/n) "; then if ! clean_up "$table_name"; then return 1 fi else if ! clean_up; then return 1 fi fi return 0 }

The DynamoDB functions used in this scenario.

############################################################################### # function dynamodb_create_table # # This function creates an Amazon DynamoDB table. # # Parameters: # -n table_name -- The name of the table to create. # -a attribute_definitions -- JSON file path of a list of attributes and their types. # -k key_schema -- JSON file path of a list of attributes and their key types. # -p provisioned_throughput -- Provisioned throughput settings for the table. # # Returns: # 0 - If successful. # 1 - If it fails. ############################################################################### function dynamodb_create_table() { local table_name attribute_definitions key_schema provisioned_throughput response local option OPTARG # Required to use getopts command in a function. ####################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_create_table" echo "Creates an Amazon DynamoDB table." echo " -n table_name -- The name of the table to create." echo " -a attribute_definitions -- JSON file path of a list of attributes and their types." echo " -k key_schema -- JSON file path of a list of attributes and their key types." echo " -p provisioned_throughput -- Provisioned throughput settings for the table." echo "" } # Retrieve the calling parameters. while getopts "n:a:k:p:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; a) attribute_definitions="${OPTARG}" ;; k) key_schema="${OPTARG}" ;; p) provisioned_throughput="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$attribute_definitions" ]]; then errecho "ERROR: You must provide an attribute definitions json file path the -a parameter." usage return 1 fi if [[ -z "$key_schema" ]]; then errecho "ERROR: You must provide a key schema json file path the -k parameter." usage return 1 fi if [[ -z "$provisioned_throughput" ]]; then errecho "ERROR: You must provide a provisioned throughput json file path the -p parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho " attribute_definitions: $attribute_definitions" iecho " key_schema: $key_schema" iecho " provisioned_throughput: $provisioned_throughput" iecho "" response=$(aws dynamodb create-table \ --table-name "$table_name" \ --attribute-definitions file://"$attribute_definitions" \ --key-schema file://"$key_schema" \ --provisioned-throughput "$provisioned_throughput") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports create-table operation failed.$response" return 1 fi return 0 } ############################################################################### # function dynamodb_describe_table # # This function returns the status of a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # # Response: # - TableStatus: # And: # 0 - Table is active. # 1 - If it fails. ############################################################################### function dynamodb_describe_table { local table_name local option OPTARG # Required to use getopts command in a function. ####################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_describe_table" echo "Describe the status of a DynamoDB table." echo " -n table_name -- The name of the table." echo "" } # Retrieve the calling parameters. while getopts "n:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi local table_status table_status=$( aws dynamodb describe-table \ --table-name "$table_name" \ --output text \ --query 'Table.TableStatus' ) local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log "$error_code" errecho "ERROR: AWS reports describe-table operation failed.$table_status" return 1 fi echo "$table_status" return 0 } ############################################################################## # function dynamodb_put_item # # This function puts an item into a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # -i item -- Path to json file containing the item values. # # Returns: # 0 - If successful. # 1 - If it fails. ############################################################################## function dynamodb_put_item() { local table_name item response local option OPTARG # Required to use getopts command in a function. ####################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_put_item" echo "Put an item into a DynamoDB table." echo " -n table_name -- The name of the table." echo " -i item -- Path to json file containing the item values." echo "" } while getopts "n:i:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; i) item="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$item" ]]; then errecho "ERROR: You must provide an item with the -i parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho " item: $item" iecho "" iecho "" response=$(aws dynamodb put-item \ --table-name "$table_name" \ --item file://"$item") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports put-item operation failed.$response" return 1 fi return 0 } ############################################################################## # function dynamodb_update_item # # This function updates an item in a DynamoDB table. # # # Parameters: # -n table_name -- The name of the table. # -k keys -- Path to json file containing the keys that identify the item to update. # -e update expression -- An expression that defines one or more attributes to be updated. # -v values -- Path to json file containing the update values. # # Returns: # 0 - If successful. # 1 - If it fails. ############################################################################# function dynamodb_update_item() { local table_name keys update_expression values response local option OPTARG # Required to use getopts command in a function. ####################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_update_item" echo "Update an item in a DynamoDB table." echo " -n table_name -- The name of the table." echo " -k keys -- Path to json file containing the keys that identify the item to update." echo " -e update expression -- An expression that defines one or more attributes to be updated." echo " -v values -- Path to json file containing the update values." echo "" } while getopts "n:k:e:v:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; k) keys="${OPTARG}" ;; e) update_expression="${OPTARG}" ;; v) values="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$keys" ]]; then errecho "ERROR: You must provide a keys json file path the -k parameter." usage return 1 fi if [[ -z "$update_expression" ]]; then errecho "ERROR: You must provide an update expression with the -e parameter." usage return 1 fi if [[ -z "$values" ]]; then errecho "ERROR: You must provide a values json file path the -v parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho " keys: $keys" iecho " update_expression: $update_expression" iecho " values: $values" response=$(aws dynamodb update-item \ --table-name "$table_name" \ --key file://"$keys" \ --update-expression "$update_expression" \ --expression-attribute-values file://"$values") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports update-item operation failed.$response" return 1 fi return 0 } ############################################################################## # function dynamodb_batch_write_item # # This function writes a batch of items into a DynamoDB table. # # Parameters: # -i item -- Path to json file containing the items to write. # # Returns: # 0 - If successful. # 1 - If it fails. ############################################################################ function dynamodb_batch_write_item() { local item response local option OPTARG # Required to use getopts command in a function. ####################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_batch_write_item" echo "Write a batch of items into a DynamoDB table." echo " -i item -- Path to json file containing the items to write." echo "" } while getopts "i:h" option; do case "${option}" in i) item="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$item" ]]; then errecho "ERROR: You must provide an item with the -i parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho " item: $item" iecho "" response=$(aws dynamodb batch-write-item \ --request-items file://"$item") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports batch-write-item operation failed.$response" return 1 fi return 0 } ############################################################################# # function dynamodb_get_item # # This function gets an item from a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # -k keys -- Path to json file containing the keys that identify the item to get. # [-q query] -- Optional JMESPath query expression. # # Returns: # The item as text output. # And: # 0 - If successful. # 1 - If it fails. ############################################################################ function dynamodb_get_item() { local table_name keys query response local option OPTARG # Required to use getopts command in a function. # ###################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_get_item" echo "Get an item from a DynamoDB table." echo " -n table_name -- The name of the table." echo " -k keys -- Path to json file containing the keys that identify the item to get." echo " [-q query] -- Optional JMESPath query expression." echo "" } query="" while getopts "n:k:q:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; k) keys="${OPTARG}" ;; q) query="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$keys" ]]; then errecho "ERROR: You must provide a keys json file path the -k parameter." usage return 1 fi if [[ -n "$query" ]]; then response=$(aws dynamodb get-item \ --table-name "$table_name" \ --key file://"$keys" \ --output text \ --query "$query") else response=$( aws dynamodb get-item \ --table-name "$table_name" \ --key file://"$keys" \ --output text ) fi local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports get-item operation failed.$response" return 1 fi if [[ -n "$query" ]]; then echo "$response" | sed "/^\t/s/\t//1" # Remove initial tab that the JMSEPath query inserts on some strings. else echo "$response" fi return 0 } ############################################################################# # function dynamodb_query # # This function queries a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # -k key_condition_expression -- The key condition expression. # -a attribute_names -- Path to JSON file containing the attribute names. # -v attribute_values -- Path to JSON file containing the attribute values. # [-p projection_expression] -- Optional projection expression. # # Returns: # The items as json output. # And: # 0 - If successful. # 1 - If it fails. ########################################################################### function dynamodb_query() { local table_name key_condition_expression attribute_names attribute_values projection_expression response local option OPTARG # Required to use getopts command in a function. # ###################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_query" echo "Query a DynamoDB table." echo " -n table_name -- The name of the table." echo " -k key_condition_expression -- The key condition expression." echo " -a attribute_names -- Path to JSON file containing the attribute names." echo " -v attribute_values -- Path to JSON file containing the attribute values." echo " [-p projection_expression] -- Optional projection expression." echo "" } while getopts "n:k:a:v:p:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; k) key_condition_expression="${OPTARG}" ;; a) attribute_names="${OPTARG}" ;; v) attribute_values="${OPTARG}" ;; p) projection_expression="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$key_condition_expression" ]]; then errecho "ERROR: You must provide a key condition expression with the -k parameter." usage return 1 fi if [[ -z "$attribute_names" ]]; then errecho "ERROR: You must provide a attribute names with the -a parameter." usage return 1 fi if [[ -z "$attribute_values" ]]; then errecho "ERROR: You must provide a attribute values with the -v parameter." usage return 1 fi if [[ -z "$projection_expression" ]]; then response=$(aws dynamodb query \ --table-name "$table_name" \ --key-condition-expression "$key_condition_expression" \ --expression-attribute-names file://"$attribute_names" \ --expression-attribute-values file://"$attribute_values") else response=$(aws dynamodb query \ --table-name "$table_name" \ --key-condition-expression "$key_condition_expression" \ --expression-attribute-names file://"$attribute_names" \ --expression-attribute-values file://"$attribute_values" \ --projection-expression "$projection_expression") fi local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports query operation failed.$response" return 1 fi echo "$response" return 0 } ############################################################################# # function dynamodb_scan # # This function scans a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # -f filter_expression -- The filter expression. # -a expression_attribute_names -- Path to JSON file containing the expression attribute names. # -v expression_attribute_values -- Path to JSON file containing the expression attribute values. # [-p projection_expression] -- Optional projection expression. # # Returns: # The items as json output. # And: # 0 - If successful. # 1 - If it fails. ########################################################################### function dynamodb_scan() { local table_name filter_expression expression_attribute_names expression_attribute_values projection_expression response local option OPTARG # Required to use getopts command in a function. # ###################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_scan" echo "Scan a DynamoDB table." echo " -n table_name -- The name of the table." echo " -f filter_expression -- The filter expression." echo " -a expression_attribute_names -- Path to JSON file containing the expression attribute names." echo " -v expression_attribute_values -- Path to JSON file containing the expression attribute values." echo " [-p projection_expression] -- Optional projection expression." echo "" } while getopts "n:f:a:v:p:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; f) filter_expression="${OPTARG}" ;; a) expression_attribute_names="${OPTARG}" ;; v) expression_attribute_values="${OPTARG}" ;; p) projection_expression="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$filter_expression" ]]; then errecho "ERROR: You must provide a filter expression with the -f parameter." usage return 1 fi if [[ -z "$expression_attribute_names" ]]; then errecho "ERROR: You must provide expression attribute names with the -a parameter." usage return 1 fi if [[ -z "$expression_attribute_values" ]]; then errecho "ERROR: You must provide expression attribute values with the -v parameter." usage return 1 fi if [[ -z "$projection_expression" ]]; then response=$(aws dynamodb scan \ --table-name "$table_name" \ --filter-expression "$filter_expression" \ --expression-attribute-names file://"$expression_attribute_names" \ --expression-attribute-values file://"$expression_attribute_values") else response=$(aws dynamodb scan \ --table-name "$table_name" \ --filter-expression "$filter_expression" \ --expression-attribute-names file://"$expression_attribute_names" \ --expression-attribute-values file://"$expression_attribute_values" \ --projection-expression "$projection_expression") fi local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports scan operation failed.$response" return 1 fi echo "$response" return 0 } ############################################################################## # function dynamodb_delete_item # # This function deletes an item from a DynamoDB table. # # Parameters: # -n table_name -- The name of the table. # -k keys -- Path to json file containing the keys that identify the item to delete. # # Returns: # 0 - If successful. # 1 - If it fails. ########################################################################### function dynamodb_delete_item() { local table_name keys response local option OPTARG # Required to use getopts command in a function. # ###################################### # Function usage explanation ####################################### function usage() { echo "function dynamodb_delete_item" echo "Delete an item from a DynamoDB table." echo " -n table_name -- The name of the table." echo " -k keys -- Path to json file containing the keys that identify the item to delete." echo "" } while getopts "n:k:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; k) keys="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi if [[ -z "$keys" ]]; then errecho "ERROR: You must provide a keys json file path the -k parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho " keys: $keys" iecho "" response=$(aws dynamodb delete-item \ --table-name "$table_name" \ --key file://"$keys") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports delete-item operation failed.$response" return 1 fi return 0 } ############################################################################### # function dynamodb_delete_table # # This function deletes a DynamoDB table. # # Parameters: # -n table_name -- The name of the table to delete. # # Returns: # 0 - If successful. # 1 - If it fails. ############################################################################### function dynamodb_delete_table() { local table_name response local option OPTARG # Required to use getopts command in a function. # bashsupport disable=BP5008 function usage() { echo "function dynamodb_delete_table" echo "Deletes an Amazon DynamoDB table." echo " -n table_name -- The name of the table to delete." echo "" } # Retrieve the calling parameters. while getopts "n:h" option; do case "${option}" in n) table_name="${OPTARG}" ;; h) usage return 0 ;; \?) echo "Invalid parameter" usage return 1 ;; esac done export OPTIND=1 if [[ -z "$table_name" ]]; then errecho "ERROR: You must provide a table name with the -n parameter." usage return 1 fi iecho "Parameters:\n" iecho " table_name: $table_name" iecho "" response=$(aws dynamodb delete-table \ --table-name "$table_name") local error_code=${?} if [[ $error_code -ne 0 ]]; then aws_cli_error_log $error_code errecho "ERROR: AWS reports delete-table operation failed.$response" return 1 fi return 0 }

The utility functions used in this scenario.

############################################################################### # function iecho # # This function enables the script to display the specified text only if # the global variable $VERBOSE is set to true. ############################################################################### function iecho() { if [[ $VERBOSE == true ]]; then echo "$@" fi } ############################################################################### # function errecho # # This function outputs everything sent to it to STDERR (standard error output). ############################################################################### function errecho() { printf "%s\n" "$*" 1>&2 } ############################################################################## # function aws_cli_error_log() # # This function is used to log the error messages from the AWS CLI. # # See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes. # # The function expects the following argument: # $1 - The error code returned by the AWS CLI. # # Returns: # 0: - Success. # ############################################################################## function aws_cli_error_log() { local err_code=$1 errecho "Error code : $err_code" if [ "$err_code" == 1 ]; then errecho " One or more S3 transfers failed." elif [ "$err_code" == 2 ]; then errecho " Command line failed to parse." elif [ "$err_code" == 130 ]; then errecho " Process received SIGINT." elif [ "$err_code" == 252 ]; then errecho " Command syntax invalid." elif [ "$err_code" == 253 ]; then errecho " The system environment or configuration was invalid." elif [ "$err_code" == 254 ]; then errecho " The service returned an error." elif [ "$err_code" == 255 ]; then errecho " 255 is a catch-all error." fi return 0 }