将事件发送到 Amazon CloudWatch Events - 适用于 Ruby 的 Amazon 开发工具包
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将事件发送到 Amazon CloudWatch Events

以下代码示例演示如何在 Amazon CloudWatch Events 中创建和触发规则。每当 Amazon 弹性计算云 (Amazon EC2) 中的可用实例更改为运行状态时,此规则将向 Amazon 简单通知服务 (Amazon SNS) 中的指定主题发送通知。此外,相关事件信息会记录到 CloudWatch 事件中的日志组中。

# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. # SPDX-License-Identifier: Apache-2.0 # The following code example shows how to create and trigger a rule in # Amazon CloudWatch Events. This rule sends a notification to the specified # topic in Amazon Simple Notification Service (Amazon SNS) whenever an # available instance in Amazon Elastic Compute Cloud (Amazon EC2) changes # to a running state. Also, related event information is logged to a log group # in Amazon CloudWatch Logs. # # This code example works with the following AWS resources through the # following functions: # # - A rule in Amazon CloudWatch Events. See the rule_exists?, rule_found?, # create_rule, and display_rule_activity functions. # - A role in AWS Identity and Access Management (IAM) to allow the rule # to work with Amazon CloudWatch Events. See role_exists?, role_found?, # and create_role. # - An Amazon EC2 instance, which triggers the rule whenever it is restarted. # See instance_restarted?. # - A topic and topic subscription in Amazon SNS for the rule to send event # notifications to. See topic_exists?, topic_found?, and create_topic. # - A log group in Amazon CloudWatch Logs to capture related event information. # See log_group_exists?, log_group_created?, log_event, and display_log_data. # # This code example requires the following AWS resources to exist in advance: # # - An Amazon EC2 instance to restart, which triggers the rule. # # The run_me function toward the end of this code example calls the # preceding functions in the correct order. require 'aws-sdk-sns' require 'aws-sdk-iam' require 'aws-sdk-cloudwatchevents' require 'aws-sdk-ec2' require 'aws-sdk-cloudwatch' require 'aws-sdk-cloudwatchlogs' require 'securerandom' # Checks whether the specified Amazon Simple Notification Service # (Amazon SNS) topic exists among those provided to this function. # This is a helper function that is called by the topic_exists? function. # # @param topics [Array] An array of Aws::SNS::Types::Topic objects. # @param topic_arn [String] The Amazon Resource Name (ARN) of the # topic to find. # @return [Boolean] true if the topic ARN was found; otherwise, false. # @example # sns_client = Aws::SNS::Client.new(region: 'us-east-1') # response = sns_client.list_topics # if topic_found?( # response.topics, # 'arn:aws:sns:us-east-1:111111111111:aws-doc-sdk-examples-topic' # ) # puts 'Topic found.' # end def topic_found?(topics, topic_arn) topics.each do |topic| return true if topic.topic_arn == topic_arn end return false end # Checks whether the specified topic exists among those available to the # caller in Amazon Simple Notification Service (Amazon SNS). # # @param sns_client [Aws::SNS::Client] An initialized Amazon SNS client. # @param topic_arn [String] The Amazon Resource Name (ARN) of the # topic to find. # @return [Boolean] true if the topic ARN was found; otherwise, false. # @example # exit 1 unless topic_exists?( # Aws::SNS::Client.new(region: 'us-east-1'), # 'arn:aws:sns:us-east-1:111111111111:aws-doc-sdk-examples-topic' # ) def topic_exists?(sns_client, topic_arn) puts "Searching for topic with ARN '#{topic_arn}'..." response = sns_client.list_topics if response.topics.count.positive? if topic_found?(response.topics, topic_arn) puts 'Topic found.' return true end while response.next_page? do response = response.next_page if response.topics.count.positive? if topic_found?(response.topics, topic_arn) puts 'Topic found.' return true end end end end puts 'Topic not found.' return false rescue StandardError => e puts "Topic not found: #{e.message}" return false end # Creates a topic in Amazon Simple Notification Service (Amazon SNS) # and then subscribes an email address to receive notifications to that topic. # # @param sns_client [Aws::SNS::Client] An initialized Amazon SNS client. # @param topic_name [String] The name of the topic to create. # @param email_address [String] The email address of the recipient to notify. # @return [String] The Amazon Resource Name (ARN) of the topic that # was created. # @example # puts create_topic( # Aws::SNS::Client.new(region: 'us-east-1'), # 'aws-doc-sdk-examples-topic', # 'mary@example.com' # ) def create_topic(sns_client, topic_name, email_address) puts "Creating the topic named '#{topic_name}'..." topic_response = sns_client.create_topic(name: topic_name) puts "Topic created with ARN '#{topic_response.topic_arn}'." subscription_response = sns_client.subscribe( topic_arn: topic_response.topic_arn, protocol: 'email', endpoint: email_address, return_subscription_arn: true ) puts 'Subscription created with ARN ' \ "'#{subscription_response.subscription_arn}'. Have the owner of the " \ "email address '#{email_address}' check their inbox in a few minutes " \ 'and confirm the subscription to start receiving notification emails.' return topic_response.topic_arn rescue StandardError => e puts "Error creating or subscribing to topic: #{e.message}" return 'Error' end # Checks whether the specified AWS Identity and Access Management (IAM) # role exists among those provided to this function. # This is a helper function that is called by the role_exists? function. # # @param roles [Array] An array of Aws::IAM::Role objects. # @param role_arn [String] The Amazon Resource Name (ARN) of the # role to find. # @return [Boolean] true if the role ARN was found; otherwise, false. # @example # iam_client = Aws::IAM::Client.new(region: 'us-east-1') # response = iam_client.list_roles # if role_found?( # response.roles, # 'arn:aws:iam::111111111111:role/aws-doc-sdk-examples-ec2-state-change' # ) # puts 'Role found.' # end def role_found?(roles, role_arn) roles.each do |role| return true if role.arn == role_arn end return false end # Checks whether the specified role exists among those available to the # caller in AWS Identity and Access Management (IAM). # # @param iam_client [Aws::IAM::Client] An initialized IAM client. # @param role_arn [String] The Amazon Resource Name (ARN) of the # role to find. # @return [Boolean] true if the role ARN was found; otherwise, false. # @example # exit 1 unless role_exists?( # Aws::IAM::Client.new(region: 'us-east-1'), # 'arn:aws:iam::111111111111:role/aws-doc-sdk-examples-ec2-state-change' # ) def role_exists?(iam_client, role_arn) puts "Searching for role with ARN '#{role_arn}'..." response = iam_client.list_roles if response.roles.count.positive? if role_found?(response.roles, role_arn) puts 'Role found.' return true end while response.next_page? do response = response.next_page if response.roles.count.positive? if role_found?(response.roles, role_arn) puts 'Role found.' return true end end end end puts 'Role not found.' return false rescue StandardError => e puts "Role not found: #{e.message}" return false end # Creates a role in AWS Identity and Access Management (IAM). # This role is used by a rule in Amazon CloudWatch Events to allow # that rule to operate within the caller's account. # This role is designed to be used specifically by this code example. # # @param iam_client [Aws::IAM::Client] An initialized IAM client. # @param role_name [String] The name of the role to create. # @return [String] The Amazon Resource Name (ARN) of the role that # was created. # @example # puts create_role( # Aws::IAM::Client.new(region: 'us-east-1'), # 'aws-doc-sdk-examples-ec2-state-change' # ) def create_role(iam_client, role_name) puts "Creating the role named '#{role_name}'..." response = iam_client.create_role( assume_role_policy_document: { 'Version': '2012-10-17', 'Statement': [ { 'Sid': '', 'Effect': 'Allow', 'Principal': { 'Service': 'events.amazonaws.com' }, 'Action': 'sts:AssumeRole' } ] }.to_json, path: '/', role_name: role_name ) puts "Role created with ARN '#{response.role.arn}'." puts 'Adding access policy to role...' iam_client.put_role_policy( policy_document: { 'Version': '2012-10-17', 'Statement': [ { 'Sid': 'CloudWatchEventsFullAccess', 'Effect': 'Allow', 'Resource': '*', 'Action': 'events:*' }, { 'Sid': 'IAMPassRoleForCloudWatchEvents', 'Effect': 'Allow', 'Resource': 'arn:aws:iam::*:role/AWS_Events_Invoke_Targets', 'Action': 'iam:PassRole' } ] }.to_json, policy_name: 'CloudWatchEventsPolicy', role_name: role_name ) puts 'Access policy added to role.' return response.role.arn rescue StandardError => e puts "Error creating role or adding policy to it: #{e.message}" puts 'If the role was created, you must add the access policy ' \ 'to the role yourself, or delete the role yourself and try again.' return 'Error' end # Checks whether the specified AWS CloudWatch Events rule exists among # those provided to this function. # This is a helper function that is called by the rule_exists? function. # # @param rules [Array] An array of Aws::CloudWatchEvents::Types::Rule objects. # @param rule_arn [String] The name of the rule to find. # @return [Boolean] true if the name of the rule was found; otherwise, false. # @example # cloudwatchevents_client = Aws::CloudWatch::Client.new(region: 'us-east-1') # response = cloudwatchevents_client.list_rules # if rule_found?(response.rules, 'aws-doc-sdk-examples-ec2-state-change') # puts 'Rule found.' # end def rule_found?(rules, rule_name) rules.each do |rule| return true if rule.name == rule_name end return false end # Checks whether the specified rule exists among those available to the # caller in AWS CloudWatch Events. # # @param cloudwatchevents_client [Aws::CloudWatchEvents::Client] # An initialized AWS CloudWatch Events client. # @param rule_name [String] The name of the rule to find. # @return [Boolean] true if the rule name was found; otherwise, false. # @example # exit 1 unless rule_exists?( # Aws::CloudWatch::Client.new(region: 'us-east-1') # 'aws-doc-sdk-examples-ec2-state-change' # ) def rule_exists?(cloudwatchevents_client, rule_name) puts "Searching for rule with name '#{rule_name}'..." response = cloudwatchevents_client.list_rules if response.rules.count.positive? if rule_found?(response.rules, rule_name) puts 'Rule found.' return true end while response.next_page? do response = response.next_page if response.rules.count.positive? if rule_found?(response.rules, rule_name) puts 'Rule found.' return true end end end end puts 'Rule not found.' return false rescue StandardError => e puts "Rule not found: #{e.message}" return false end # Creates a rule in AWS CloudWatch Events. # This rule is triggered whenever an available instance in # Amazon Elastic Compute Cloud (Amazon EC2) changes to the specified state. # This rule is designed to be used specifically by this code example. # # Prerequisites: # # - A role in AWS Identity and Access Management (IAM) that is designed # to be used specifically by this code example. # - A topic in Amazon Simple Notification Service (Amazon SNS). # # @param cloudwatchevents_client [Aws::CloudWatchEvents::Client] # An initialized AWS CloudWatch Events client. # @param rule_name [String] The name of the rule to create. # @param rule_description [String] Some description for this rule. # @param instance_state [String] The state that available instances in # Amazon Elastic Compute Cloud (Amazon EC2) must change to, to # trigger this rule. # @param role_arn [String] The Amazon Resource Name (ARN) of the IAM role. # @param target_id [String] Some identifying string for the rule's target. # @param topic_arn [String] The ARN of the Amazon SNS topic. # @return [Boolean] true if the rule was created; otherwise, false. # @example # exit 1 unless rule_created?( # Aws::CloudWatch::Client.new(region: 'us-east-1'), # 'aws-doc-sdk-examples-ec2-state-change', # 'Triggers when any available EC2 instance starts.', # 'running', # 'arn:aws:iam::111111111111:role/aws-doc-sdk-examples-ec2-state-change', # 'sns-topic', # 'arn:aws:sns:us-east-1:111111111111:aws-doc-sdk-examples-topic' # ) def rule_created?( cloudwatchevents_client, rule_name, rule_description, instance_state, role_arn, target_id, topic_arn ) puts "Creating rule with name '#{rule_name}'..." put_rule_response = cloudwatchevents_client.put_rule( name: rule_name, description: rule_description, event_pattern: { 'source': [ 'aws.ec2' ], 'detail-type': [ 'EC2 Instance State-change Notification' ], 'detail': { 'state': [ instance_state ] } }.to_json, state: 'ENABLED', role_arn: role_arn ) puts "Rule created with ARN '#{put_rule_response.rule_arn}'." put_targets_response = cloudwatchevents_client.put_targets( rule: rule_name, targets: [ { id: target_id, arn: topic_arn } ] ) if put_targets_response.key?(:failed_entry_count) && put_targets_response.failed_entry_count > 0 puts 'Error(s) adding target to rule:' put_targets_response.failed_entries.each do |failure| puts failure.error_message end return false else return true end rescue StandardError => e puts "Error creating rule or adding target to rule: #{e.message}" puts 'If the rule was created, you must add the target ' \ 'to the rule yourself, or delete the rule yourself and try again.' return false end # Checks to see whether the specified log group exists among those available # to the caller in Amazon CloudWatch Logs. # # @param cloudwatchlogs_client [Aws::CloudWatchLogs::Client] An initialized # Amazon CloudWatch Logs client. # @param log_group_name [String] The name of the log group to find. # @return [Boolean] true if the log group name was found; otherwise, false. # @example # exit 1 unless log_group_exists?( # Aws::CloudWatchLogs::Client.new(region: 'us-east-1'), # 'aws-doc-sdk-examples-cloudwatch-log' # ) def log_group_exists?(cloudwatchlogs_client, log_group_name) puts "Searching for log group with name '#{log_group_name}'..." response = cloudwatchlogs_client.describe_log_groups( log_group_name_prefix: log_group_name ) if response.log_groups.count.positive? response.log_groups.each do |log_group| if log_group.log_group_name == log_group_name puts 'Log group found.' return true end end end puts 'Log group not found.' return false rescue StandardError => e puts "Log group not found: #{e.message}" return false end # Creates a log group in Amazon CloudWatch Logs. # # @param cloudwatchlogs_client [Aws::CloudWatchLogs::Client] An initialized # Amazon CloudWatch Logs client. # @param log_group_name [String] The name of the log group to create. # @return [Boolean] true if the log group name was created; otherwise, false. # @example # exit 1 unless log_group_created?( # Aws::CloudWatchLogs::Client.new(region: 'us-east-1'), # 'aws-doc-sdk-examples-cloudwatch-log' # ) def log_group_created?(cloudwatchlogs_client, log_group_name) puts "Attempting to create log group with the name '#{log_group_name}'..." cloudwatchlogs_client.create_log_group(log_group_name: log_group_name) puts 'Log group created.' return true rescue StandardError => e puts "Error creating log group: #{e.message}" return false end # Writes an event to a log stream in Amazon CloudWatch Logs. # # Prerequisites: # # - A log group in Amazon CloudWatch Logs. # - A log stream within the log group. # # @param cloudwatchlogs_client [Aws::CloudWatchLogs::Client] An initialized # Amazon CloudWatch Logs client. # @param log_group_name [String] The name of the log group. # @param log_stream_name [String] The name of the log stream within # the log group. # @param message [String] The message to write to the log stream. # @param sequence_token [String] If available, the sequence token from the # message that was written immediately before this message. This sequence # token is returned by Amazon CloudWatch Logs whenever you programmatically # write a message to the log stream. # @return [String] The sequence token that is returned by # Amazon CloudWatch Logs after successfully writing the message to the # log stream. # @example # puts log_event( # Aws::EC2::Client.new(region: 'us-east-1'), # 'aws-doc-sdk-examples-cloudwatch-log' # '2020/11/19/53f985be-199f-408e-9a45-fc242df41fEX', # "Instance 'i-033c48ef067af3dEX' restarted.", # '495426724868310740095796045676567882148068632824696073EX' # ) def log_event( cloudwatchlogs_client, log_group_name, log_stream_name, message, sequence_token ) puts "Attempting to log '#{message}' to log stream '#{log_stream_name}'..." event = { log_group_name: log_group_name, log_stream_name: log_stream_name, log_events: [ { timestamp: (Time.now.utc.to_f.round(3) * 1_000).to_i, message: message } ] } unless sequence_token.empty? event[:sequence_token] = sequence_token end response = cloudwatchlogs_client.put_log_events(event) puts 'Message logged.' return response.next_sequence_token rescue StandardError => e puts "Message not logged: #{e.message}" end # Restarts an Amazon Elastic Compute Cloud (Amazon EC2) instance # and adds information about the related activity to a log stream # in Amazon CloudWatch Logs. # # Prerequisites: # # - The Amazon EC2 instance to restart. # - The log group in Amazon CloudWatch Logs to add related activity # information to. # # @param ec2_client [Aws::EC2::Client] An initialized Amazon EC2 client. # @param cloudwatchlogs_client [Aws::CloudWatchLogs::Client] # An initialized Amazon CloudWatch Logs client. # @param instance_id [String] The ID of the instance. # @param log_group_name [String] The name of the log group. # @return [Boolean] true if the instance was restarted and the information # was written to the log stream; otherwise, false. # @example # exit 1 unless instance_restarted?( # Aws::EC2::Client.new(region: 'us-east-1'), # Aws::CloudWatchLogs::Client.new(region: 'us-east-1'), # 'i-033c48ef067af3dEX', # 'aws-doc-sdk-examples-cloudwatch-log' # ) def instance_restarted?( ec2_client, cloudwatchlogs_client, instance_id, log_group_name ) log_stream_name = "#{Time.now.year}/#{Time.now.month}/#{Time.now.day}/" \ "#{SecureRandom.uuid}" cloudwatchlogs_client.create_log_stream( log_group_name: log_group_name, log_stream_name: log_stream_name ) sequence_token = '' puts "Attempting to stop the instance with the ID '#{instance_id}'. " \ 'This might take a few minutes...' ec2_client.stop_instances(instance_ids: [instance_id]) ec2_client.wait_until(:instance_stopped, instance_ids: [instance_id]) puts 'Instance stopped.' sequence_token = log_event( cloudwatchlogs_client, log_group_name, log_stream_name, "Instance '#{instance_id}' stopped.", sequence_token ) puts 'Attempting to restart the instance. This might take a few minutes...' ec2_client.start_instances(instance_ids: [instance_id]) ec2_client.wait_until(:instance_running, instance_ids: [instance_id]) puts 'Instance restarted.' sequence_token = log_event( cloudwatchlogs_client, log_group_name, log_stream_name, "Instance '#{instance_id}' restarted.", sequence_token ) return true rescue StandardError => e puts 'Error creating log stream or stopping or restarting the instance: ' \ "#{e.message}" log_event( cloudwatchlogs_client, log_group_name, log_stream_name, "Error stopping or starting instance '#{instance_id}': #{e.message}", sequence_token ) return false end # Displays information about activity for a rule in Amazon CloudWatch Events. # # Prerequisites: # # - A rule in Amazon CloudWatch Events. # # @param cloudwatch_client [Amazon::CloudWatch::Client] An initialized # Amazon CloudWatch client. # @param rule_name [String] The name of the rule. # @param start_time [Time] The timestamp that determines the first datapoint # to return. Can also be expressed as DateTime, Date, Integer, or String. # @param end_time [Time] The timestamp that determines the last datapoint # to return. Can also be expressed as DateTime, Date, Integer, or String. # @param period [Integer] The interval, in seconds, to check for activity. # @example # display_rule_activity( # Aws::CloudWatch::Client.new(region: 'us-east-1'), # 'aws-doc-sdk-examples-ec2-state-change', # Time.now - 600, # Start checking from 10 minutes ago. # Time.now, # Check up until now. # 60 # Check every minute during those 10 minutes. # ) def display_rule_activity( cloudwatch_client, rule_name, start_time, end_time, period ) puts 'Attempting to display rule activity...' response = cloudwatch_client.get_metric_statistics( namespace: 'AWS/Events', metric_name: 'Invocations', dimensions: [ { name: 'RuleName', value: rule_name } ], start_time: start_time, end_time: end_time, period: period, statistics: ['Sum'], unit: 'Count' ) if response.key?(:datapoints) && response.datapoints.count.positive? puts "The event rule '#{rule_name}' was triggered:" response.datapoints.each do |datapoint| puts " #{datapoint.sum} time(s) at #{datapoint.timestamp}" end else puts "The event rule '#{rule_name}' was not triggered during the " \ 'specified time period.' end rescue StandardError => e puts "Error getting information about event rule activity: #{e.message}" end # Displays log information for all of the log streams in a log group in # Amazon CloudWatch Logs. # # Prerequisites: # # - A log group in Amazon CloudWatch Logs. # # @param cloudwatchlogs_client [Amazon::CloudWatchLogs::Client] An initialized # Amazon CloudWatch Logs client. # @param log_group_name [String] The name of the log group. # @example # display_log_data( # Amazon::CloudWatchLogs::Client.new(region: 'us-east-1'), # 'aws-doc-sdk-examples-cloudwatch-log' # ) def display_log_data(cloudwatchlogs_client, log_group_name) puts 'Attempting to display log stream data for the log group ' \ "named '#{log_group_name}'..." describe_log_streams_response = cloudwatchlogs_client.describe_log_streams( log_group_name: log_group_name, order_by: 'LastEventTime', descending: true ) if describe_log_streams_response.key?(:log_streams) && describe_log_streams_response.log_streams.count.positive? describe_log_streams_response.log_streams.each do |log_stream| get_log_events_response = cloudwatchlogs_client.get_log_events( log_group_name: log_group_name, log_stream_name: log_stream.log_stream_name ) puts "\nLog messages for '#{log_stream.log_stream_name}':" puts '-' * (log_stream.log_stream_name.length + 20) if get_log_events_response.key?(:events) && get_log_events_response.events.count.positive? get_log_events_response.events.each do |event| puts event.message end else puts 'No log messages for this log stream.' end end end rescue StandardError => e puts 'Error getting information about the log streams or their messages: ' \ "#{e.message}" end # Displays a reminder to the caller to manually clean up any associated # AWS resources that they no longer need. # # @param topic_name [String] The name of the Amazon SNS topic. # @param role_name [String] The name of the IAM role. # @param rule_name [String] The name of the Amazon CloudWatch Events rule. # @param log_group_name [String] The name of the Amazon CloudWatch Logs log group. # @param instance_id [String] The ID of the Amazon EC2 instance. # @example # manual_cleanup_notice( # 'aws-doc-sdk-examples-topic', # 'aws-doc-sdk-examples-cloudwatch-events-rule-role', # 'aws-doc-sdk-examples-ec2-state-change', # 'aws-doc-sdk-examples-cloudwatch-log', # 'i-033c48ef067af3dEX' # ) def manual_cleanup_notice( topic_name, role_name, rule_name, log_group_name, instance_id ) puts '-' * 10 puts 'Some of the following AWS resources might still exist in your account.' puts 'If you no longer want to use this code example, then to clean up' puts 'your AWS account and avoid unexpected costs, you might want to' puts 'manually delete any of the following resources if they exist:' puts "- The Amazon SNS topic named '#{topic_name}'." puts "- The IAM role named '#{role_name}'." puts "- The Amazon CloudWatch Events rule named '#{rule_name}'." puts "- The Amazon CloudWatch Logs log group named '#{log_group_name}'." puts "- The Amazon EC2 instance with the ID '#{instance_id}'." end # Full example call: def run_me # Properties for the Amazon SNS topic. topic_name = 'aws-doc-sdk-examples-topic' email_address = 'mary@example.com' # Properties for the IAM role. role_name = 'aws-doc-sdk-examples-cloudwatch-events-rule-role' # Properties for the Amazon CloudWatch Events rule. rule_name = 'aws-doc-sdk-examples-ec2-state-change' rule_description = 'Triggers when any available EC2 instance starts.' instance_state = 'running' target_id = 'sns-topic' # Properties for the Amazon EC2 instance. instance_id = 'i-033c48ef067af3dEX' # Properties for displaying the event rule's activity. start_time = Time.now - 600 # Go back over the past 10 minutes # (10 minutes * 60 seconds = 600 seconds). end_time = Time.now period = 60 # Look back every 60 seconds over the past 10 minutes. # Properties for the Amazon CloudWatch Logs log group. log_group_name = 'aws-doc-sdk-examples-cloudwatch-log' # AWS service clients for this code example. region = 'us-east-1' sts_client = Aws::STS::Client.new(region: region) sns_client = Aws::SNS::Client.new(region: region) iam_client = Aws::IAM::Client.new(region: region) cloudwatchevents_client = Aws::CloudWatchEvents::Client.new(region: region) ec2_client = Aws::EC2::Client.new(region: region) cloudwatch_client = Aws::CloudWatch::Client.new(region: region) cloudwatchlogs_client = Aws::CloudWatchLogs::Client.new(region: region) # Get the caller's account ID for use in forming # Amazon Resource Names (ARNs) that this code relies on later. account_id = sts_client.get_caller_identity.account # If the Amazon SNS topic doesn't exist, create it. topic_arn = "arn:aws:sns:#{region}:#{account_id}:#{topic_name}" unless topic_exists?(sns_client, topic_arn) topic_arn = create_topic(sns_client, topic_name, email_address) if topic_arn == 'Error' puts 'Could not create the Amazon SNS topic correctly. Program stopped.' manual_cleanup_notice( topic_name, role_name, rule_name, log_group_name, instance_id ) exit 1 end end # If the IAM role doesn't exist, create it. role_arn = "arn:aws:iam::#{account_id}:role/#{role_name}" unless role_exists?(iam_client, role_arn) role_arn = create_role(iam_client, role_name) if role_arn == 'Error' puts 'Could not create the IAM role correctly. Program stopped.' manual_cleanup_notice( topic_name, role_name, rule_name, log_group_name, instance_id ) end end # If the Amazon CloudWatch Events rule doesn't exist, create it. unless rule_exists?(cloudwatchevents_client, rule_name) unless rule_created?( cloudwatchevents_client, rule_name, rule_description, instance_state, role_arn, target_id, topic_arn ) puts 'Could not create the Amazon CloudWatch Events rule correctly. ' \ 'Program stopped.' manual_cleanup_notice( topic_name, role_name, rule_name, log_group_name, instance_id ) end end # If the Amazon CloudWatch Logs log group doesn't exist, create it. unless log_group_exists?(cloudwatchlogs_client, log_group_name) unless log_group_created?(cloudwatchlogs_client, log_group_name) puts 'Could not create the Amazon CloudWatch Logs log group ' \ 'correctly. Program stopped.' manual_cleanup_notice( topic_name, role_name, rule_name, log_group_name, instance_id ) end end # Restart the Amazon EC2 instance, which triggers the rule. unless instance_restarted?( ec2_client, cloudwatchlogs_client, instance_id, log_group_name ) puts 'Could not restart the instance to trigger the rule. ' \ 'Continuing anyway to show information about the rule and logs...' end # Display how many times the rule was triggered over the past 10 minutes. display_rule_activity( cloudwatch_client, rule_name, start_time, end_time, period ) # Display related log data in Amazon CloudWatch Logs. display_log_data(cloudwatchlogs_client, log_group_name) # Reminder the caller to clean up any AWS resources that are used # by this code example and are no longer needed. manual_cleanup_notice( topic_name, role_name, rule_name, log_group_name, instance_id ) end run_me if $PROGRAM_NAME == __FILE__