corymhall / cdk-diff-action

GitHub action to post CDK diff to PR comments

👋 Hello! I'm Cory.

• 🔭 I’m currently working at Pulumi
• 💥 Former AWS CDK team member
• 🌱 I’m currently learning about Pulumi!
• ⚡ Fun fact: I love Neovim ❤️
• 📘 I have a blog

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📝 Latest Blog Posts

• CDK Diff GitHub Action
• Go Construct Patterns
• Building, bundling, and deploying applications with the AWS CDK
• Bootstrapping multiple AWS accounts for AWS CDK using CloudFormation StackSets

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cdk-diff-action's Issues

Fails with error "Body is too long" for apps with many stacks/stages

Hi @corymhall , I tried using this action on a private repo with many stacks to replace a different (but worse) diff tool. You know which repo. It has a lot of stacks and it seems like this causes the action to fail with the following error:

Error commenting stages:  RequestError [HttpError]: Validation Failed: {"resource":"IssueComment","code":"unprocessable","field":"data","message":"Body is too long (maximum is 65536 characters)"}

Maybe an option to have a comment per stack? Or do some clever magic to shorten the body?

Show commit id on comment

GitHub Actions can't find the @v1 version of the action

It seems the example in the readme file is using @v1 as the version of the action. GitHub can't find this version. Using @v1.0.0 works, so I guess there either needs to be a new tag/release with just v1 or the example should be updated to use v1.0.0.

The action itself works really well, thank you!

Support `diffForStages` and `failOnDestructiveChanges`

This is basically the inverse of the current noDiffForStages and noFailOnDestructiveChanges.

But that's probably just one solution to my actual use case:

• I have a large app with many stacks/stages across different regions
• For reasons, I cannot have a single role that can perform diff for all stages across all regions
• I am looking for a way to group my stacks into multiple jobs that each use a different role and diff a subset of stages
• Currently I have to exclude the unwanted stages, which causes a lot of repetition.

PS: Not using failOnDestructiveChanges. Just threw this in for good measure. 😂

Ignore certain stages

Add the ability to ignore certain stages.

1. Ignore stages completely
2. Show the diff, but don't fail anything for the stage

Summarize non-asset changes

handle authentication issues

I don't think we are currently handling authentication issues very well. We should at a minimum

• Compare the credentials with the stack account and if they don't match, throw an error
• Log a warning if the lookup role is not found

Feature Request: Allow to run this on subfolders

The action should accept an optional "subfolder" where the CDK project lives. This is useful for monorepo projects, where there might be a folder for backend, folder for frontend and folder for IaC, rather than everything being in the root.

Update PR description instead of making a comment

Will it be possible to post to the PR description instead of commenting on the PR?

This will reduce noise, because GitHub notifies for every comment created on a PR. I am not sure if the PR description length will be the limiting factor here. If it does, maybe post to the PR description first, but if it is too long, truncate and create the rest as comments.

Show empty diff for stacks with no changes

Allow overriding destructive changes failure with labels

Error commenting stages: Error: Comment for stack foobar is too long, please report this as a bug

#32 is fixed and works great, however we are still getting the following error for one of the stacks. Reporting this for completeness. FWIW I think we are getting this because the diff (incorrectly, but probably a configuration issue on my end) believes this is a new stack and so it just lists all changes which is very long.

Further ideas for fixing:

• truncate if needed
• maybe there's a way to give github extra long strings, just not as a comment?
• The IAM change list is very long. It's obviously useful though.

Run corymhall/cdk-diff-action@e154417b2bd6f6c53234d7432043044d965e69d5
  
Error commenting stages:  Error: Comment for stack foobar is too long, please report this as a bug https://github.com/corymhall/cdk-diff-action/issues/new
Error: Comment for stack foobar is too long, please report this as a bug https://github.com/corymhall/cdk-diff-action/issues/new
    at StageProcessor.commentStacks (/home/runner/work/_actions/corymhall/cdk-diff-action/e154417b2bd6f6c53234d7432043044d965e69d5/lib/stage-processor.js:94:1)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at StageProcessor.commentStages (/home/runner/work/_actions/corymhall/cdk-diff-action/e154417b2bd6f6c53234d7432043044d965e69d5/lib/stage-processor.js:[12](https://github.com/cdklabs/cdk-ops/actions/runs/7299188526/job/19891550494?pr=3055#step:8:13)5:1)
    at run (/home/runner/work/_actions/corymhall/cdk-diff-action/e154417b2bd6f6c53234d7432043044d965e69d5/lib/action.js:61:1)
Error performing diff:  Error: Comment for stack foobar is too long, please report this as a bug https://github.com/corymhall/cdk-diff-action/issues/new
    at StageProcessor.commentStacks (/home/runner/work/_actions/corymhall/cdk-diff-action/e154417b2bd6f6c53234d7432043044d965e69d5/lib/stage-processor.js:94:1)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at StageProcessor.commentStages (/home/runner/work/_actions/corymhall/cdk-diff-action/e154417b2bd6f6c53234d7432043044d965e69d5/lib/stage-processor.js:125:1)
    at run (/home/runner/work/_actions/corymhall/cdk-diff-action/e[15](https://github.com/cdklabs/cdk-ops/actions/runs/7299188526/job/19891550494?pr=3055#step:8:16)44[17](https://github.com/cdklabs/cdk-ops/actions/runs/7299188526/job/19891550494?pr=3055#step:8:18)b2bd6f6c53234d743[20](https://github.com/cdklabs/cdk-ops/actions/runs/7299188526/job/19891550494?pr=3055#step:8:21)43044d965e69d5/lib/action.js:61:1)