Implement the sync state calculation for the kubernetes livestate plugin

[Warashi]

What this PR does:

as title

Why we need it:

We want to support DriftDetection feature with k8s plugin

Which issue(s) this PR fixes:

Part of #5363

Does this PR introduce a user-facing change?: No

• How are users affected by this change:
• Is this breaking change:
• How to migrate (if breaking change):

[codecov]

Codecov Report

Attention: Patch coverage is 41.55844% with 45 lines in your changes missing coverage. Please review.

Project coverage is 25.68%. Comparing base (317a7c9) to head (3278eba).
Report is 6 commits behind head on master.

Files with missing lines	Patch %	Lines
.../app/pipedv1/plugin/kubernetes/livestate/plugin.go	41.55%	44 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5676      +/-   ##
==========================================
- Coverage   25.73%   25.68%   -0.06%     
==========================================
  Files         478      476       -2     
  Lines       51400    50973     -427     
==========================================
- Hits        13230    13092     -138     
+ Misses      37166    36890     -276     
+ Partials     1004      991      -13     

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[Warashi]

reference implementation is here

pipecd/pkg/app/piped/driftdetector/kubernetes/detector.go

Lines 385 to 422 in 57c48c1

	func makeSyncState(r *provider.DiffListResult, commit string) model.ApplicationSyncState {
	if r.NoChange() {
	return model.ApplicationSyncState{
	Status: model.ApplicationSyncStatus_SYNCED,
	ShortReason: "",
	Reason: "",
	Timestamp: time.Now().Unix(),
	}
	}
	total := len(r.Adds) + len(r.Deletes) + len(r.Changes)
	shortReason := fmt.Sprintf("There are %d manifests not synced (%d adds, %d deletes, %d changes)", total, len(r.Adds), len(r.Deletes), len(r.Changes))
	if len(commit) >= 7 {
	commit = commit[:7]
	}
	var b strings.Builder
	b.WriteString(fmt.Sprintf("Diff between the defined state in Git at commit %s and actual state in cluster:\n\n", commit))
	b.WriteString("--- Actual (LiveState)\n+++ Expected (Git)\n\n")
	details := r.Render(provider.DiffRenderOptions{
	MaskSecret: true,
	MaskConfigMap: true,
	MaxChangedManifests: 3,
	// Currently, we do not use the diff command to render the result
	// because Kubernetes adds a large number of default values to the
	// running manifest that causes a wrong diff text.
	UseDiffCommand: false,
	})
	b.WriteString(details)
	return model.ApplicationSyncState{
	Status: model.ApplicationSyncStatus_OUT_OF_SYNC,
	ShortReason: shortReason,
	Reason: b.String(),
	Timestamp: time.Now().Unix(),
	}
	}

[ffjlabo]

[ask] Does the logic for calculateSyncState depend on each resource kind?

[Warashi]

The ConfigMap and Secrets are masked. The other kinds are treated as the same.

[ffjlabo]

I see. Then, we can fix the test case name to clarify the spec for the function.
For example "changed two resources". WDYT?

[Warashi]

OK, it's a good name to show the spec.
Also, I'll change the second test case, deployment spec changes, to changed one resource.

[Warashi]

Fixed on this commit
9a4b84a

[ffjlabo]

[nit] It would be nice to add some testcases to cover the spec.

• The maximum count of the changes is three.
• ConfigMap and Secret are masked on the text

[Warashi]

Thank you!
Added at this commit 2306bc9

[ffjlabo]

Sorry, just only one more nit 🙏

[ffjlabo]

LGTM