Deploy Go Lambda functions with .zip file archives

1. Download the lambda library from GitHub.

   go get github.com/aws/aws-lambda-go/lambda

2. Compile your executable.

   GOOS=linux GOARCH=amd64 go build -o main main.go

   Setting GOOS to linux ensures that the compiled executable is compatible with the Go runtime, even if you compile it in a non-Linux environment.

3. (Optional) If your main package consists of multiple files, use the following go build command to compile the package:

   GOOS=linux GOARCH=amd64 go build main

4. (Optional) You may need to compile packages with CGO_ENABLED=0 set on Linux:

   GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -o main main.go

   This command creates a stable binary package for standard C library (libc) versions, which may be different on Lambda and other devices.

5. Lambda uses POSIX file permissions, so you may need to set permissions for the deployment package folder before you create the .zip file archive.

6. Create a deployment package by packaging the executable in a .zip file.

   zip main.zip main

1. Download the lambda library from GitHub.

   go get github.com/aws/aws-lambda-go/lambda

2. Download the build-lambda-zip tool from GitHub.

   go.exe install github.com/aws/aws-lambda-go/cmd/build-lambda-zip@latest

3. Use the tool from your GOPATH to create a .zip file. If you have a default installation of Go, the tool is typically in %USERPROFILE%\Go\bin. Otherwise, navigate to where you installed the Go runtime and do one of the following:

   cmd.exe

   In cmd.exe, run the following:

   set GOOS=linux
   set GOARCH=amd64
   set CGO_ENABLED=0
   go build -o main main.go
   %USERPROFILE%\Go\bin\build-lambda-zip.exe -o main.zip main

   PowerShell

   In PowerShell, run the following:

   $env:GOOS = "linux"
   $env:GOARCH = "amd64"
   $env:CGO_ENABLED = "0"
   go build -o main main.go
   ~\Go\Bin\build-lambda-zip.exe -o main.zip main

1. Create a trust policy giving the Lambda service permission to assume the execution role. Copy the following JSON and create a file named trust-policy.json in the current directory.

   {
     "Version": "2012-10-17",
     "Statement": [
       {
         "Effect": "Allow",
         "Principal": {
           "Service": "lambda.amazonaws.com"
         },
         "Action": "sts:AssumeRole"
       }
     ]
   }

2. Create the execution role.

   aws iam create-role --role-name lambda-ex --assume-role-policy-document file://trust-policy.json

   You should see the following output. Make a note of your role's ARN. You will need this to create your function.

   {
       "Role": {
           "Path": "/",
           "RoleName": "lambda-ex",
           "RoleId": "AROAQFOXMPL6TZ6ITKWND",
           "Arn": "arn:aws-cn:iam::123456789012:role/lambda-ex",
           "CreateDate": "2020-01-17T23:19:12Z",
           "AssumeRolePolicyDocument": {
               "Version": "2012-10-17",
               "Statement": [
                   {
                       "Effect": "Allow",
                       "Principal": {
                           "Service": "lambda.amazonaws.com"
                       },
                       "Action": "sts:AssumeRole"
                   }
               ]
           }
       }
   }

3. Add permissions to the role using the attach-role-policy command. In the example below, you add the AWSLambdaBasicExecutionRole managed policy, which allows your Lambda function to upload logs to CloudWatch. If your Lambda function interacts with other Amazon services, such as Amazon S3 or DynamoDB, you will need to add policies allowing your Lambda function to access these services. See Amazon managed policies for Lambda features for more information.

   aws iam attach-role-policy --role-name lambda-ex --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

4. Create the function.

   aws lambda create-function --function-name my-function --runtime go1.x --role arn:aws:iam::123456789012:role/lambda-ex --handler main --zip-file fileb://main.zip

Using Amazon SAM to build Go for AL2 function

1. Update the Amazon SAM template to use the provided.al2 runtime. Also set the BuildMethod to makefile.

   Resources:
     HelloWorldFunction:
       Type: AWS::Serverless::Function
       Properties:
         CodeUri: hello-world/
         Handler: my.bootstrap.file
         Runtime: provided.al2
         Architectures: [arm64]  
       Metadata:
         BuildMethod: makefile        
         

   Remove the Architectures property to build the package for the x86_64 instruction set architecture.

2. Add file makefile to the project folder, with the following contents:

   GOOS=linux go build -o bootstrap
   	cp ./bootstrap $(ARTIFACTS_DIR)/.