fix: prevent confusing error messages when `installed: false` (#508)

This removes `release: "your_release_name" not found` errors seen for releases with `installed: false` when running `helmfile sync` and `helmfile apply`.

The problem was that helmfile had been running `helm status` to detect releases to be deleted. helmfile now use `helm list ^YOUR_RELEASE_NAME$` to detect if the release is currently installed or not, which emits no error-like logs on against uninstalled releases.

Fixes #507

Fixes #507

helmexec/exec.go

@@ -110,6 +110,13 @@ func (helm *execer) ReleaseStatus(name string) error {
 	return err
 }
 
+func (helm *execer) List(filter string) (string, error) {
+	helm.logger.Infof("Listing releases matching %v", filter)
+	out, err := helm.exec(append([]string{"list", filter})...)
+	helm.write(out)
+	return string(out), err
+}
+
 func (helm *execer) DecryptSecret(name string) (string, error) {
 	// Prevents https://github.com/roboll/helmfile/issues/258
 	helm.decryptionMutex.Lock()

helmexec/helmexec.go

@@ -17,6 +17,6 @@ type Interface interface {
 	ReleaseStatus(name string) error
 	DeleteRelease(name string, flags ...string) error
 	TestRelease(name string, flags ...string) error
-
+	List(filter string) (string, error)
 	DecryptSecret(name string) (string, error)
 }

state/state.go

@@ -252,24 +252,25 @@ func (st *HelmState) prepareSyncReleases(helm helmexec.Interface, additionalValu
 	return res, errs
 }
 
+func isReleaseInstalled(helm helmexec.Interface, release ReleaseSpec) (bool, error) {
+	out, err := helm.List("^" + release.Name + "$")
+	if err != nil {
+		return false, err
+	} else if out != "" {
+		return true, nil
+	}
+	return false, nil
+}
+
 func (st *HelmState) DetectReleasesToBeDeleted(helm helmexec.Interface) ([]*ReleaseSpec, error) {
 	detected := []*ReleaseSpec{}
 	for i, _ := range st.Releases {
 		release := st.Releases[i]
 		if release.Installed != nil && !*release.Installed {
-			err := helm.ReleaseStatus(release.Name)
+			installed, err := isReleaseInstalled(helm, release)
 			if err != nil {
-				switch e := err.(type) {
-				case *exec.ExitError:
-					// Propagate any non-zero exit status from the external command like `helm` that is failed under the hood
-					status := e.Sys().(syscall.WaitStatus)
-					if status.ExitStatus() != 1 {
-						return nil, e
-					}
-				default:
-					return nil, e
-				}
-			} else {
+				return nil, err
+			} else if installed {
 				detected = append(detected, &release)
 			}
 		}
@@ -304,7 +305,10 @@ func (st *HelmState) SyncReleases(helm helmexec.Interface, additionalValues []st
 				chart := normalizeChart(st.basePath, release.Chart)
 				var relErr *ReleaseError
 				if release.Installed != nil && !*release.Installed {
-					if err := helm.ReleaseStatus(release.Name); err == nil {
+					installed, err := isReleaseInstalled(helm, *release)
+					if err != nil {
+						relErr = &ReleaseError{release, err}
+					} else if installed {
 						if err := helm.DeleteRelease(release.Name, "--purge"); err != nil {
 							relErr = &ReleaseError{release, err}
 						}

state/state_test.go

@@ -614,6 +614,9 @@ func (helm *mockHelmExec) ReleaseStatus(release string) error {
 func (helm *mockHelmExec) DeleteRelease(name string, flags ...string) error {
 	return nil
 }
+func (helm *mockHelmExec) List(filter string) (string, error) {
+	return "", nil
+}
 func (helm *mockHelmExec) DecryptSecret(name string) (string, error) {
 	return "", nil
 }