Readable CodePipeline deploy notifications with AWS Lambda

AWS CodePipeline is a flexible and start-up friendly (i.e. cheap) way to get CI/CD (Continous Integration/Continous Deployment). git push origin master is all it takes to commit, test & deploy. That’s great.

But deploy fail/success notifications are a pain. Here’s how an SMS looks like, sent via CloudWatch Events and SNS:

Filmhub>{“version”:”0",”id”:”12345678–3a74–42ca-55b7–41a6029aefc2",”detail-type”:”CodePipeline Pipeline Execution State Change”,”source”:”aws.codepipeline”,”account”:”123456789101",”time”:”2018–10–08T00:02:14Z”,”region”:”us-east-1",”resources”:[“arn:aws:codepipeline:us-east-1:123456789101:basics-production-WebPipeline-ABC0DEF1HIJ2”],”detail”:{“pipeline”:”basics-production-WebPipeline-ABC0DEF1HIJ2",”execution-id”:”12345678-fa67–4716–8582–2bd632ee0018",”state”:”SUCCEEDED”,”version”:15}}`

Can you spot the successful deploy? Then you’re fluent in raw minified JSON. I’d rather have something like this:

Filmhub> Deploy of master SUCCEEDED

Here’s how we solved this.

A little lambda helps

Instead of targeting SNS directly to send the raw CloudWatch Event coming from CodePipeline, we will put this Lambda helper function “in the middle”.

Simple, but wiring it up is a bit more involved.

First, the function needs two environment variables: TOPIC_ARN is the ARN of the SNS topic to send the notification to, and BRANCH is the git branch we trigger a CodePipeline execution with. We have everything in CloudFormation, here is the Lambda function resource in the template:

CloudFormation template — lambda function

The DeployBranch is the git branch CodePipeline is triggered by. We use a template parameter to define it.

CloudFormation template — DeployBranch parameter

Let’s invoke the Lambda function. A Lambda policy defines how — as the target of a CloudWatch event rule. Here is both.

All that’s left is the actual SNS topic. Here I’m subscribed to receive deploy notifications on my cell phone.

How it works

To summarize how this works:

1. A git push to Github (or CodeCommit) starts a CodePipeline deploy
2. This fires a CloudWatch event rule which invokes our Lambda function
3. The Lambda function publishes a clean deploy message to an SNS topic
4. SNS sends emails and SMS messages to all subscribers of the SNS topic

Here’s also the complete CloudFormation template with all resources.

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