feat(environment): Allow missing environment in helmfile.yaml, partly. (#294)

helmfile as of today ensures that all the targeted helmfile.yaml to have the specified environment defined in it.
That is, `helmfile --environment prod -f helmfile.d/ sync` fails if any helmfile under `helmfile.d/` is missing the `production` environment.

This changes the validation logic, so that helmfile fails only when all the helmfiles miss the environment.

Resolves #279

main.go

@@ -539,14 +539,15 @@ func findAndIterateOverDesiredStates(fileOrDir string, converge func(*state.Helm
 	if err != nil {
 		return err
 	}
-	allSelectorNotMatched := true
+	noTargetFoundForAllHelmfiles := true
 	for _, f := range desiredStateFiles {
 		logger.Debugf("Processing %s", f)
 		yamlBuf, err := tmpl.NewFileRenderer(ioutil.ReadFile, "", environment.EmptyEnvironment).RenderTemplateFileToBuffer(f)
 		if err != nil {
 			return err
 		}
-		state, helm, noReleases, err := loadDesiredStateFromFile(
+
+		st, helm, noReleasesMatchingSelector, err := loadDesiredStateFromFile(
 			yamlBuf.Bytes(),
 			f,
 			kubeContext,
@@ -555,12 +556,21 @@ func findAndIterateOverDesiredStates(fileOrDir string, converge func(*state.Helm
 			env,
 			logger,
 		)
-		if err != nil {
-			return err
-		}
 
-		if len(state.Helmfiles) > 0 {
-			for _, globPattern := range state.Helmfiles {
+		var noTarget bool
+		if err != nil {
+			switch stateLoadErr := err.(type) {
+			// Addresses https://github.com/roboll/helmfile/issues/279
+			case *state.StateLoadError:
+				switch stateLoadErr.Cause.(type) {
+				case *state.UndefinedEnvError:
+					noTarget = true
+				}
+			default:
+				return err
+			}
+		} else if len(st.Helmfiles) > 0 {
+			for _, globPattern := range st.Helmfiles {
 				matches, err := filepath.Glob(globPattern)
 				if err != nil {
 					return fmt.Errorf("failed processing %s: %v", globPattern, err)
@@ -573,19 +583,25 @@ func findAndIterateOverDesiredStates(fileOrDir string, converge func(*state.Helm
 				}
 			}
 			return nil
+		} else {
+			noTarget = noReleasesMatchingSelector
 		}
 
-		allSelectorNotMatched = allSelectorNotMatched && noReleases
-		if noReleases {
+		noTargetFoundForAllHelmfiles = noTargetFoundForAllHelmfiles && noTarget
+		if noTarget {
 			continue
 		}
-		errs := converge(state, helm)
-		if err := clean(state, errs); err != nil {
+		errs := converge(st, helm)
+		if err := clean(st, errs); err != nil {
 			return err
 		}
 	}
-	if allSelectorNotMatched {
-		logger.Error("specified selector did not match any releases in any helmfile")
+	if noTargetFoundForAllHelmfiles {
+		logger.Errorf(
+			"err: no releases found that matches specified selector(%s) and environment(%s), in any helmfile",
+			strings.Join(selectors, ", "),
+			env,
+		)
 		os.Exit(2)
 	}
 	return nil
@@ -651,7 +667,7 @@ func directoryExistsAt(path string) bool {
 func loadDesiredStateFromFile(yaml []byte, file string, kubeContext, namespace string, labels []string, env string, logger *zap.SugaredLogger) (*state.HelmState, helmexec.Interface, bool, error) {
 	st, err := state.CreateFromYaml(yaml, file, env, logger)
 	if err != nil {
-		return nil, nil, false, fmt.Errorf("failed to read %s: %v", file, err)
+		return nil, nil, false, err
 	}
 
 	if st.Context != "" {

state/create.go

@@ -13,6 +13,23 @@ import (
 	"path/filepath"
 )
 
+type StateLoadError struct {
+	msg   string
+	Cause error
+}
+
+func (e *StateLoadError) Error() string {
+	return fmt.Sprintf("%s: %v", e.msg, e.Cause)
+}
+
+type UndefinedEnvError struct {
+	msg string
+}
+
+func (e *UndefinedEnvError) Error() string {
+	return e.msg
+}
+
 func CreateFromYaml(content []byte, file string, env string, logger *zap.SugaredLogger) (*HelmState, error) {
 	return createFromYamlWithFileReader(content, file, env, logger, ioutil.ReadFile)
 }
@@ -22,7 +39,7 @@ func createFromYamlWithFileReader(content []byte, file string, env string, logge
 
 	state.basePath, _ = filepath.Abs(filepath.Dir(file))
 	if err := yaml.UnmarshalStrict(content, &state); err != nil {
-		return nil, err
+		return nil, &StateLoadError{fmt.Sprintf("failed to read %s", file), err}
 	}
 	state.FilePath = file
 
@@ -38,7 +55,7 @@ func createFromYamlWithFileReader(content []byte, file string, env string, logge
 
 	e, err := state.loadEnv(env, readFile)
 	if err != nil {
-		return nil, err
+		return nil, &StateLoadError{fmt.Sprintf("failed to read %s", file), err}
 	}
 	state.env = *e
 
@@ -92,7 +109,7 @@ func (state *HelmState) loadEnv(name string, readFile func(string) ([]byte, erro
 			}
 		}
 	} else if name != DefaultEnv {
-		return nil, fmt.Errorf("environment \"%s\" is not defined in \"%s\"", name, state.FilePath)
+		return nil, &UndefinedEnvError{msg: fmt.Sprintf("environment \"%s\" is not defined", name)}
 	}
 
 	return &environment.Environment{Name: name, Values: envVals}, nil