[ECS] PipeCD failed to recognize last success deployment in PlanPreview

[vuongvm812]

What happened:

• During the first deployment of a service, that deployment failed so the next PR for fixing that service will always lead to the below error Error: Reason: failed while calculating diff, cannot get the old manifests without the last successful deployment

What you expected to happen:

• If the first deployment of a service failed, the next Plan Preview for that service should consider it as a new deployment instead of finding last successful deployment.

How to reproduce it:

• Create PipeCD app.pipecd.yaml config file.
• Create an app on the Web UI.
• Let that first deployment fail.
• Create another PR to fix that first deployment.

Environment:

• piped version: v0.51.0
• control-plane version: v0.51.0
• Others:
  • actions-plan-preview: v1.7.6

[ani1609]

@t-kikuc hey, can i work on this?

[t-kikuc]

@ani1609 Thank you. Please leave investigation note here before submitting a PR

[t-kikuc]

@vuongvm812 You mean it failed while PlanPreview, not while deployment, right?

[t-kikuc]

@vuongvm812 I changed the title to avoid misunderstanding. If my title is wrong, please tell me 👍

[vuongvm812]

@vuongvm812 You mean it failed while PlanPreview, not while deployment, right?

Sorry for missing your replies. Yes this is when we ran Plan Preview, not deployment.

[armistcxy]

@t-kikuc Hi, I've noticed that this issue have stayed idle for a while

I have my quick investigation here:

• The error breakdown into 2 parts: "failed while calculating diff" and "cannot get the old manifests without the last successful"
• The first part belong to line 269 pkg/app/piped/planpreview/builder.go, which just only wrap the error when calculating the diff between old and new manifest.
• The second part belong to line 49 - line 52 pkg/app/piped/planpreview/ecsdiff.go

if lastCommit == "" {
	fmt.Fprintf(buf, "failed to find the commit of the last successful deployment")
	return nil, fmt.Errorf("cannot get the old manifests without the last successful deployment")
}

lastCommit will be empty since the first deployment was failed.

The simplest way solution maybe follow how kubernetesdiff.go handles calculating diff.

var oldManifests, newManifests []provider.Manifest
...
if lastSuccessfulCommit != "" {
	runningDSP := deploysource.NewProvider(
		b.workingDir,
		deploysource.NewGitSourceCloner(b.gitClient, b.repoCfg, "running", lastSuccessfulCommit),
		*app.GitPath,
		b.secretDecrypter,
	)
	oldManifests, err = loadKubernetesManifests(ctx, *app, runningDSP, b.appManifestsCache, b.gitClient, b.logger)
	if err != nil {
		fmt.Fprintf(buf, "failed to load kubernetes manifests at the running commit (%v)\n", err)
		return nil, err
	}
}

This mean if lastCommit is empty, oldManifest will be empty and provider.DiffList will result in empty change, which also mean this will trigger

if result.NoChange() {
	fmt.Fprintln(buf, "No changes were detected")
	return &diffResult{
		summary:  "No changes were detected",
		noChange: true,
	}, nil
}

I want to ask you some questions before futher investigation

1. The code checking lastCommit != "" is also applied for cloud run and lambda, why there was no other similar report/issue
2. If I resolve this issue, should I record video or capture screen as a proof

And can you also assign this issue for me.

[armistcxy]

Hi @t-kikuc, I just wanted to check whether this bug is low priority, since PlanPreview might be moved to a separate repository and everyone is focusing on the PipeCD v1 release. If PipeCD v1 is nearly released, let me know where I can help with