Creating a Lambda Function - AWS SDK for Go (version 1)

We announced the upcoming end-of-support for AWS SDK for Go V1. We recommend that you migrate to AWS SDK for Go V2. For dates, additional details, and information on how to migrate, please refer to the linked announcement.

Creating a Lambda Function

The following example creates the Lambda function functionName in the us-west-2 region using the following values:

  • Role ARN: resourceArn. In most cases, you need to attach only the AWSLambdaExecute managed policy to the policy for this role.

  • Function entry point: handler

  • Runtime: runtime

  • Zip file: zipFileName + .zip

  • Bucket: bucketName

  • Key: zipFileName

The first step is to import the packages we use in the example.

import (
    "flag"
    "fmt"
    "io/ioutil"

    "github.com/aws/aws-sdk-go/aws/session"
    "github.com/aws/aws-sdk-go/service/lambda"
)

Get the zip file name, bucket name, function name, handler, ARN, and runtime values from the command line. If any are missing, print and error message and quit.

zipFile := flag.String("z", "", "The name of the ZIP file, without the .zip extension.")
bucket := flag.String("b", "", "the name of bucket to which the ZIP file is uploaded.")
function := flag.String("f", "", "The name of the Lambda function.")
handler := flag.String("h", "main", "The name of the package.class handling the call.")
roleARN := flag.String("a", "", "The ARN of the role that calls the function.")
runtime := flag.String("r", "go1.x", "The runtime for the function.")

flag.Parse()

if *zipFile == "" || *bucket == "" || *function == "" || *handler == "" || *roleARN == "" || *runtime == "" {
    fmt.Println("You must supply a zip file name, bucket name, function name, handler (package) name, role ARN, and runtime value.")
    return
}

Create the session and Lambda client and get the contents of the zip file. If you cannot read the zip file contents, print an error message and quit.

sess := session.Must(session.NewSessionWithOptions(session.Options{
    SharedConfigState: session.SharedConfigEnable,
}))

Next, create the structures for the input argument to the CreateFunction function.

createCode := &lambda.FunctionCode{
    //      S3Bucket:        bucket,
    //      S3Key:           zipFile,
    //      S3ObjectVersion: aws.String("1"),
    ZipFile: contents,
}

createArgs := &lambda.CreateFunctionInput{
    Code:         createCode,
    FunctionName: function,
    Handler:      handler,
    Role:         role,
    Runtime:      runtime,
}

Finally, call CreateFunction and display a message with the result of the call.

result, err := svc.CreateFunction(createArgs)

See the complete example on GitHub.