awscli - lambda function update trigger

Question

We have a lambda@edge function which listens to cloudfront distribution origin request and response events. We are trying to automate the deployment. So far we succeeding in updating the code and publishing the new version.

  - npm install
  - zip -r lambda.zip *
  - aws lambda update-function-code --function-name LambdaFunction1 --zip-file fileb://lambda.zip
  - aws lambda publish-version --function-name LambdaFunction1

But how do we update CloudFront triggers to point to the latest published version?

Answer 1

Perform the following steps-

1. Check the versions of lambda first by running the following cli command. And the Fetch the FunctionARN of the latest version.

aws lambda list-versions-by-function --function-name LAMBDA_NAME

2. Get the cloudfront distribution json data first by the following command.

aws cloudfront get-distribution-config --id DISTRIBUTION_ID > cf_config.json

3. Create a file named updated_cf_config.json by fetching DistributionConfig key from the cf_config.json.

4. Now Put the FunctionARN of the latest Version of lambda inside the "LambdaFunctionAssociations" -> "LambdaFunctionARN"

5. Update cloudfront distribution by running the command. To update the cloudfront distribution we need ETAG from cf_config.json:

aws cloudfront update-distribution --distribution-config file://cf_config.json --id DISTRIBUTION_ID --if-match ETAG