feat: show diff preview when sync --interactive is used by vomba · Pull Request #2603 · helmfile/helmfile

vomba · 2026-05-20T10:51:50Z

Summary

When running helmfile sync --interactive, show a helm-diff preview of the changes before prompting for confirmation. This mirrors the existing helmfile apply --interactive behavior, giving users visibility into what will change before they commit to the sync.

Changes

cmd/sync.go: Added 13 diff-related CLI flags (--context, --output, --diff-args, --suppress, --suppress-secrets, --show-secrets, --no-hooks, --suppress-diff, --skip-diff-on-install, --include-tests, --detailed-exitcode, --strip-trailing-cr, --suppress-output-line-regex) to the sync command
pkg/config/sync.go: Added corresponding fields to SyncOptions and getter methods on SyncImpl so it satisfies DiffConfigProvider
pkg/app/app.go: In SyncState, when interactive is true and the config implements DiffConfigProvider, runs r.diff() to show a diff preview, then incorporates the output into the confirmation prompt
pkg/app/app_sync_test.go: Added TestSyncInteractive with 3 test cases covering non-interactive, interactive-with-confirmation, and interactive-with-rejection paths

Testing

All tests pass (go vet, go test -race):

=== RUN   TestSyncInteractive
=== RUN   TestSyncInteractive/non-interactive:_sync_proceeds_without_diff
=== RUN   TestSyncInteractive/interactive_with_diff:_user_confirms
=== RUN   TestSyncInteractive/interactive_with_diff:_user_rejects
--- PASS: TestSyncInteractive (0.34s)
=== RUN   TestSync
...
--- PASS: TestSync (5.70s)

Signed-off-by: vomba <[email protected]>

Copilot

Pull request overview

This PR aims to align helmfile sync --interactive with helmfile apply --interactive by showing a helm-diff preview before prompting the user for confirmation.

Changes:

Added diff-related CLI flags to helmfile sync and corresponding config plumbing so sync configs can act as a DiffConfigProvider.
Updated App.SyncState to run a diff preview during interactive sync and incorporate the resulting “affected releases” message into the confirmation prompt.
Added unit tests covering interactive vs non-interactive sync behavior.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
cmd/sync.go	Adds diff-related flags to the `sync` command.
pkg/config/sync.go	Extends `SyncOptions`/`SyncImpl` with diff-related fields/getters to satisfy `DiffConfigProvider`.
pkg/app/app.go	Runs a diff preview during interactive sync and uses it in the confirmation prompt.
pkg/app/app_sync_test.go	Adds `TestSyncInteractive` for interactive/non-interactive sync paths.

Comments suppressed due to low confidence (1)

pkg/app/app.go:2337

The diff preview runs before r.helm.SetExtraArgs(GetArgs(c.Args(), r.state)...) is applied, so --args / helmDefaults.args won’t affect the interactive helm diff preview. This can make the preview differ from the subsequent sync (e.g., kubeconfig/context-related args). Consider setting extra args before calling r.diff() (or have r.diff apply them internally) so preview and execution use the same Helm invocation context.

	var errs []error

	r.helm.SetExtraArgs(GetArgs(c.Args(), r.state)...)

+				TakeOwnership:           diffC.TakeOwnership(),
+				DetectedKubeVersion:     detectedKubeVersion,
+			}
+			infoMsgPtr, _, _, diffErrs := r.diff(false, false, diffC, diffOpts)


+	f.BoolVar(&syncOptions.SuppressDiff, "suppress-diff", false, "suppress diff in the output. Usable in new installs")
+	f.BoolVar(&syncOptions.SkipDiffOnInstall, "skip-diff-on-install", false, "Skips running helm-diff on releases being newly installed on this sync. Useful when the release manifests are too huge to be reviewed, or it's too time-consuming to diff at all")
+	f.BoolVar(&syncOptions.IncludeTests, "include-tests", false, "enable the diffing of the helm test hooks")
+	f.BoolVar(&syncOptions.DetailedExitcode, "detailed-exitcode", false, "return a non-zero exit code 2 instead of 0 when there were changes detected AND the changes are synced successfully")


+			// Use ForEachState to gain access to the Run so we can inject Ask
+			forEachErr := app.ForEachState(func(run *Run) (bool, []error) {
+				run.Ask = func(msg string) bool {
+					return tc.confirm
+				}
+				return app.SyncState(run, applyConfig{
+					concurrency: 1,
+					interactive: tc.interactive,
+					skipNeeds:   true,
+					logger:      logger,
+				})
+			}, false)


+				}
+				for flagIdx := range wantUpgrades[relIdx].Flags {
+					if wantUpgrades[relIdx].Flags[flagIdx] != helm.Releases[relIdx].Flags[flagIdx] {
+						t.Errorf("releaes[%d].flags[%d]: got %v, want %v", relIdx, flagIdx, helm.Releases[relIdx].Flags[flagIdx], wantUpgrades[relIdx].Flags[flagIdx])


yxxhero · 2026-05-20T12:57:51Z

@vomba

- Pass detailed-exitcode flag to diff preview so changes are properly detected and labeled - Wire up --detailed-exitcode flag on sync to return exit code 2 when changes are detected and synced (mirrors apply behavior) - Set extra args before diff preview so --args/helmDefaults.args affect the preview - Assert helm.Diffed was called in interactive test cases - Fix typo releaes -> releases in test error messages Signed-off-by: vomba <[email protected]>

Copilot

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

+	if ec, ok := c.(interface{ DetailedExitcode() bool }); ok && ec.DetailedExitcode() && any {
+		code := 2
+
+		return &Error{msg: "Identified at least one change", code: &code}
+	}


+	changesApplied := operationsAttempted && len(errs) == 0
+
+	return true, changesApplied, errs


+	f.StringVar(&syncOptions.DiffOutput, "output", "", "output format for diff plugin")
+	f.StringVar(&syncOptions.DiffArgs, "diff-args", "", `pass args to helm-diff`)
+	f.StringArrayVar(&syncOptions.Suppress, "suppress", nil, "suppress specified Kubernetes objects in the diff output. Can be provided multiple times. For example: --suppress KeycloakClient --suppress VaultSecret")
+	f.BoolVar(&syncOptions.SuppressSecrets, "suppress-secrets", false, "suppress secrets in the diff output. highly recommended to specify on CI/CD use-cases")
+	f.BoolVar(&syncOptions.ShowSecrets, "show-secrets", false, "do not redact secret values in the diff output. should be used for debug purpose only")
+	f.BoolVar(&syncOptions.NoHooks, "no-hooks", false, "do not diff changes made by hooks")
+	f.BoolVar(&syncOptions.SuppressDiff, "suppress-diff", false, "suppress diff in the output. Usable in new installs")
+	f.BoolVar(&syncOptions.SkipDiffOnInstall, "skip-diff-on-install", false, "Skips running helm-diff on releases being newly installed on this sync. Useful when the release manifests are too huge to be reviewed, or it's too time-consuming to diff at all")
+	f.BoolVar(&syncOptions.IncludeTests, "include-tests", false, "enable the diffing of the helm test hooks")
+	f.BoolVar(&syncOptions.DetailedExitcode, "detailed-exitcode", false, "return a non-zero exit code 2 instead of 0 when there were changes detected AND the changes are synced successfully")
+	f.BoolVar(&syncOptions.StripTrailingCR, "strip-trailing-cr", false, "strip trailing carriage return on input")
+	f.StringArrayVar(&syncOptions.SuppressOutputLineRegex, "suppress-output-line-regex", nil, "a list of regex patterns to suppress output lines from diff output")


yxxhero · 2026-05-20T23:39:37Z

@vomba new comments.

Co-authored-by: Copilot Autofix powered by AI <[email protected]>

- Update --detailed-exitcode help text to reflect that sync does not run a diff by default (unlike apply) - Add '(interactive preview only)' to all diff-related flag help texts to clarify they only take effect with --interactive Signed-off-by: vomba <[email protected]>

Sync and Apply both return exit code 2 when --detailed-exitcode is set, but Sync was printing 'Identified at least one change' while Apply printed nothing. Removing the message from Sync for consistency. Signed-off-by: vomba <[email protected]>

Signed-off-by: vomba <[email protected]>

vomba requested review from aditmeno, itscaro, mumoshu, xiaomudk, yxxhero and zhaque44 as code owners May 20, 2026 10:51

vomba force-pushed the feat/sync-diff-interactive-flag branch 2 times, most recently from f7fd021 to 43cd7be Compare May 20, 2026 10:56

yxxhero requested a review from Copilot May 20, 2026 12:50

Copilot started reviewing on behalf of yxxhero May 20, 2026 12:50 View session

feat: show diff preview when sync --interactive is used

58fa8b1

Signed-off-by: vomba <[email protected]>

yxxhero force-pushed the feat/sync-diff-interactive-flag branch from 43cd7be to 58fa8b1 Compare May 20, 2026 12:53

Copilot AI reviewed May 20, 2026

View reviewed changes

vomba force-pushed the feat/sync-diff-interactive-flag branch from ff2d12e to 940a364 Compare May 20, 2026 14:15

yxxhero requested a review from Copilot May 20, 2026 21:22

Copilot started reviewing on behalf of yxxhero May 20, 2026 21:22 View session

Copilot AI reviewed May 20, 2026

View reviewed changes

yxxhero and others added 2 commits May 21, 2026 08:47

Potential fix for pull request finding

72b91af

Co-authored-by: Copilot Autofix powered by AI <[email protected]>

vomba force-pushed the feat/sync-diff-interactive-flag branch from feb499b to af804c6 Compare May 21, 2026 07:58

vomba force-pushed the feat/sync-diff-interactive-flag branch from 5fceb95 to 2e14154 Compare May 21, 2026 08:09

test: add coverage for --detailed-exitcode exit code 2 on sync

7533a7e

Signed-off-by: vomba <[email protected]>

vomba force-pushed the feat/sync-diff-interactive-flag branch from b0a70f4 to 7533a7e Compare May 21, 2026 10:04

yxxhero approved these changes May 21, 2026

View reviewed changes

yxxhero merged commit 2a1574b into helmfile:main May 21, 2026
16 checks passed

BrewTestBot mentioned this pull request May 22, 2026

helmfile 1.5.2 Homebrew/homebrew-core#284150

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feat: show diff preview when sync --interactive is used#2603

feat: show diff preview when sync --interactive is used#2603
yxxhero merged 6 commits into
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vomba:feat/sync-diff-interactive-flag

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		changesApplied := operationsAttempted && len(errs) == 0

		return true, changesApplied, errs

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vomba commented May 20, 2026

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