Example: Create an AWS CodeCommit trigger for an AWS Lambda function

Sign in to the AWS Management Console and open the AWS Lambda console at https://console.aws.amazon.com/lambda/.

On the Lambda Functions page, choose Create function. (If you have not used Lambda before, choose Get Started Now.)

On the Create function page, choose Author from scratch. In Function Name, provide a name for the function, for example MyLambdaFunctionforCodeCommit. In Runtime, choose the language you want to use to write your function, and then choose Create function.

On the Configuration tab, choose Add trigger.

In Trigger configuration, choose CodeCommit from the services drop-down list.

Choose Add.

On the Configuration page, in Function Code, in Code entry type, choose Edit code inline.. In Runtime, choose Node.js. If you want to create a sample Python function, choose Python.

In Code entry type, choose Edit code inline, and then replace the hello world code with one of the two following samples.

For Node.js:

import {
  CodeCommitClient,
  GetRepositoryCommand,
} from "@aws-sdk/client-codecommit";

const codecommit = new CodeCommitClient({ region: "your-region" });

/**
 * @param {{ Records: { codecommit: { references: { ref: string }[] }, eventSourceARN: string  }[]} event
 */
export const handler = async (event) => {
  // Log the updated references from the event
  const references = event.Records[0].codecommit.references.map(
    (reference) => reference.ref,
  );
  console.log("References:", references);

  // Get the repository from the event and show its git clone URL
  const repository = event.Records[0].eventSourceARN.split(":")[5];
  const params = {
    repositoryName: repository,
  };

  try {
    const data = await codecommit.send(new GetRepositoryCommand(params));
    console.log("Clone URL:", data.repositoryMetadata.cloneUrlHttp);
    return data.repositoryMetadata.cloneUrlHttp;
  } catch (error) {
    console.error("Error:", error);
    throw new Error(
      `Error getting repository metadata for repository ${repository}`,
    );
  }
};

For Python:

import json
import boto3

codecommit = boto3.client("codecommit")


def lambda_handler(event, context):
    # Log the updated references from the event
    references = {
        reference["ref"]
        for reference in event["Records"][0]["codecommit"]["references"]
    }
    print("References: " + str(references))

    # Get the repository from the event and show its git clone URL
    repository = event["Records"][0]["eventSourceARN"].split(":")[5]
    try:
        response = codecommit.get_repository(repositoryName=repository)
        print("Clone URL: " + response["repositoryMetadata"]["cloneUrlHttp"])
        return response["repositoryMetadata"]["cloneUrlHttp"]
    except Exception as e:
        print(e)
        print(
            "Error getting repository {}. Make sure it exists and that your repository is in the same region as this function.".format(
                repository
            )
        )
        raise e

In the Permissions tab, in Execution role, choose the role to open it in the IAM console. Edit the attached policy to add GetRepository permission for the repository you want to use the trigger.

Open the CodeCommit console at https://console.aws.amazon.com/codesuite/codecommit/home.

In Repositories, choose the repository where you want to view triggers.

In the navigation pane for the repository, choose Settings, and then choose Triggers.

Review the list of triggers for the repository. You should see the trigger you created in the Lambda console. Choose it from the list and then choose Test trigger. This option attempts to invoke the function with sample data about your repository, including the most recent commit ID for the repository. (If no commit history exists, sample values consisting of zeroes are generated instead.) This helps you confirm that you have correctly configured access between AWS CodeCommit and the Lambda function.

To further verify the functionality of the trigger, make and push a commit to the repository where you configured the trigger. You should see a response from the Lambda function on the Monitoring tab for that function in the Lambda console. From the Monitoring tab, choose View logs in CloudWatch. The CloudWatch console opens in a new tab and displays events for your function. Select the log stream from the list that corresponds to the time you pushed your commit. You should see event data similar to the following:

START RequestId: 70afdc9a-EXAMPLE Version: $LATEST
2015-11-10T18:18:28.689Z	70afdc9a-EXAMPLE	References: [ 'refs/heads/main' ]
2015-11-10T18:18:29.814Z	70afdc9a-EXAMPLE	Clone URL: https://git-codecommit.us-east-2.amazonaws.com/v1/repos/MyDemoRepo
END RequestId: 70afdc9a-EXAMPLE
REPORT RequestId: 70afdc9a-EXAMPLE Duration: 1126.87 ms Billed Duration: 1200 ms Memory Size: 128 MB Max Memory Used: 14 MB