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Ileriayo Adebiyi
Ileriayo Adebiyi

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Debugging an AWS CodeBuild Failure

#aws #cloud #devops #cloudnative

My introduction to AWS CodeBuild was an error log sent to me by a software engineer. I saw in the logs a NestJS application, as indicated by the nest start command in it.

I immediately recognized from the name of the AWS service (CodeBuild) and from the logs that this had to be a build system, similar to what you could achieve in GitHub Actions.

Well, a nest build command was failing; however, it seemed to run successfully on the engineer's computer.

I needed to understand how CodeBuild was being triggered, and like most build systems, there ought to be a build config. I didn't find anything useful while browsing the AWS Console, so I looked at the root of the repo and found a buildspec.yml. This had to be it.

Looking in the file, I found something that made sense:

version: 0.2

phases:
  install:
    commands:
      - npm install
      - npm install typescript
  pre_build:
    commands:
      ...
  build:
    commands:
      ...
  post_build:
    commands:
      ...
artifacts:
  files:
    - '**/*'
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There must be some way to run this locally in a container, I thought, and true to that, I found that I could.

First, I pulled the Amazon Linux 2 image:

docker pull public.ecr.aws/codebuild/amazonlinux-x86_64-standard:4.0
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Next, I pulled the agent (x86_64 version)

docker pull public.ecr.aws/codebuild/local-builds:latest
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Afterwards, I downloaded a bash script into the root of the repository and made it executable:

$ curl -O  https://raw.githubusercontent.com/aws/aws-codebuild-docker-images/master/local_builds/codebuild_build.sh

$ chmod +x codebuild_build.sh
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Finally, I ran the script with the

./codebuild_build.sh -i public.ecr.aws/codebuild/amazonlinux-x86_64-standard:4.0 -a <output directory>
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And then the logs came out just like I saw on the AWS Console.

After examing the logs and the application code, it was the typescript version that needed a change.

version: 0.2

phases:
  install:
    commands:
      - npm install
      - npm install typescript@5.5.4
...
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Running the script one more time with this new buildspec.yml, there was no failure.

I made a PR, and that problem was fixed.

Pros of Debugging locally:

  1. Cost: AWS charges you for every build on AWS CodeBuild. Rerunning the CodeBuild with costs low.
  2. Velocity: You can make changes locally and test all within an IDE, skipping the need for commits, PR reviews, etc.

Cons of Debuigging locally:

  1. The Amazon Linux Image may be large and might pose a challenge in a low internet environment.

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