Update Lambda@Edge Function

deploy-to-edge.js

const fs = require('fs');
const {exec} = require('child_process');

const cloudFrontDistributionId = 'EXXXXXXXXXXXXX';
const currentCloudFrontConfigFile = 'cf_config.json';
const updatedCloudFrontConfigFile = 'cf_config_updated.json';
const lambdaPublishResponseFile = 'lambda_publish_response.json';

exec(`aws cloudfront get-distribution-config --id ${cloudFrontDistributionId} > ${currentCloudFrontConfigFile}`, (error, stdout, stderr) => {
    if (error) {
        console.error(`error: ${error.message}`);

        return process.exit(1);
    }

    if (stderr) {
        console.error(`stderr: ${stderr}`);

        return process.exit(1);
    }

    if (!fs.existsSync(lambdaPublishResponseFile)) {
        console.error('Run this first: `aws lambda publish-version --function-name LambdaFunctionName > lambda_publish_response.json`');

        return process.exit(1);
    }

    let cfConfig = JSON.parse(fs.readFileSync(currentCloudFrontConfigFile));
    const etag = cfConfig.ETag;
    const lambdaPublishData = JSON.parse(fs.readFileSync(lambdaPublishResponseFile));

    cfConfig.DistributionConfig.DefaultCacheBehavior.LambdaFunctionAssociations.Items[0].LambdaFunctionARN = lambdaPublishData.FunctionArn;

    fs.writeFileSync(updatedCloudFrontConfigFile, JSON.stringify(cfConfig.DistributionConfig));

    exec(`aws cloudfront update-distribution --distribution-config file://${updatedCloudFrontConfigFile} --id ${cloudFrontDistributionId} --if-match ${etag}`, (error, stdout, stderr) => {
        if (error) {
            return console.error(`error: ${error.message}`);
        }

        if (stderr) {
            return console.error(`stderr: ${stderr}`);
        }

        console.log(`stdout: ${stdout}`);

        fs.unlinkSync(lambdaPublishResponseFile);
        fs.unlinkSync(currentCloudFrontConfigFile);
        fs.unlinkSync(updatedCloudFrontConfigFile);
    });
});

Update Lambda@Edge Function.md

First, zip up your function:

rm lambda.zip; zip -r lambda.zip lambda-function/*

Then, update the current working function:

aws lambda update-function-code --zip-file fileb://lambda.zip --function-name LambdaFunctionName

Next, publish the current working function, and capture the response:

aws lambda publish-version --function-name LambdaFunctionName > lambda_publish_response.json

Finally, run deploy-to-edge.js. It will take the response found in lambda_publish_response.json, and update the CloudFront Distribution specified to use the new version of the Lambda function.

I just stumbled upon this via a Google search that led me to this StackOverflow comment… you just saved my day!

I was gonna spend hours building this script when I ended up just copying and adapting it a bit (mostly to use process.env to get some variables like the CloudFront Distribution ID and the lambda function's name and add some process.exitCode = 1 to show the pipeline has failed).

THANK YOU SO MUCH!

@viki53 I'm glad I could help!