Synth generates new assets on each run

[kborisov-ottofeller]

I have a strange issue in my CodePipeline. 'cdk synth' generates new assets for all bundled assets in each run.
For example here are an asset for a lambda:
index.js index.meta.json index.js.map
At first run it is placed in the asset.fdce21718a4f7a8581303fce3acd019cef5a860374122d76dec11000589d2253, the next run it goes into asset.9d18db04ce59290e3a058c8458c6171a49376b3f8c4aca15f59edd5f6d326334
The index.js and index.js.map are exactly the same and here is the difference between index.meta.json:
`
Comparing files index.meta.json and ASSET.9D18DB04CE59290E3A058C8458C6171A49376B3F8C4ACA15F59EDD5F6D326334\INDEX.META.JSON
***** index.meta.json
"outputs": { "cdk.out/asset.fdce21718a4f7a8581303fce3acd019cef5a860374122d76dec11000589d2253/index.js.map": { "imports": [],
***** ASSET.9D18DB04CE59290E3A058C8458C6171A49376B3F8C4ACA15F59EDD5F6D326334\INDEX.META.JSON
"outputs": { "cdk.out/asset.9d18db04ce59290e3a058c8458c6171a49376b3f8c4aca15f59edd5f6d326334/index.js.map": { "imports": [],

---

***** index.meta.json
},"cdk.out/asset.fdce21718a4f7a8581303fce3acd019cef5a860374122d76dec11000589d2253/index.js": { "imports": [
***** ASSET.9D18DB04CE59290E3A058C8458C6171A49376B3F8C4ACA15F59EDD5F6D326334\INDEX.META.JSON
},"cdk.out/asset.9d18db04ce59290e3a058c8458c6171a49376b3f8c4aca15f59edd5f6d326334/index.js": { "imports": [

---

`
So difference basically only in the reference on the asset hash which should not affect the hash.
Currently all the lambda functions are being re-synthesized and the cache does not help.

This does not happen for assets, which contains images only or other fixed files, it will be something like asset.3d0e5fc...8801 on every run.

I couldn't reproduce this locally. This happens only on CodeBuild container. CDK version is 2.97.0.

Could somebody suggest how this can be fixed or debugged further?

[kborisov-ottofeller]

Looks like the asset ids are being generated based on the current path. The path in the container is new each time (/codebuild/output/srcXXXXXXXX/src). Because of that the assets are new on each synth().

It looks like I am doing something wrong. Any input would be really helpful.

What is the standard way to do synthesized files caching in CodePipeline? How can I make CodeBuild to not generate new assets each time?

[kborisov-ottofeller]

Nevermind I found out that our lambdas have their base class redefined, and the bundling uses full path instead of the relative one.
Update: actually it is on our code base, it's a bug in AWS CDK, caused by this PR: link. It indtroduces an absolute path instead of a relative one which goes later in the hash.

[github-actions[bot]]

Hello! Reopening this discussion to make it searchable.