Do not fail due to missing env in base helmfile (#1009)

When helmfile is run with `--environment NAME` and there was a base hemlfile that misses `environments`, helmfile had been trying to load env values for NAME and failing.

A base helmfile is allowed to reference values from within itself, but that's optional. In other words, a base helmfile that misses the env is okay as long as it doesn't self-reference env values.

So, this change allows missing env and env values while loading base helmfile. After loading, a base helmfile can fail due to referencing missing env values, but that's okay.

Fixes #1008

pkg/app/app_test.go

@@ -177,6 +177,42 @@ releases:
 	}
 }
 
+func TestVisitDesiredStatesWithReleasesFiltered_Issue1008_MissingNonDefaultEnvInBase(t *testing.T) {
+	files := map[string]string{
+		"/path/to/base.yaml": `
+helmDefaults:
+  wait: true
+`,
+		"/path/to/helmfile.yaml": `
+bases:
+- base.yaml
+environments:
+  test:
+releases:
+- name: zipkin
+  chart: stable/zipkin
+`,
+	}
+	fs := testhelper.NewTestFs(files)
+	app := &App{
+		KubeContext: "default",
+		Logger:      helmexec.NewLogger(os.Stderr, "debug"),
+		Namespace:   "",
+		Env:         "test",
+	}
+	app = injectFs(app, fs)
+	noop := func(st *state.HelmState, helm helmexec.Interface) []error {
+		return []error{}
+	}
+
+	err := app.VisitDesiredStatesWithReleasesFiltered(
+		"helmfile.yaml", noop,
+	)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+}
+
 func TestVisitDesiredStatesWithReleasesFiltered_MissingEnvValuesFileHandler(t *testing.T) {
 	testcases := []struct {
 		name        string

pkg/state/create.go

@@ -116,10 +116,10 @@ func (c *StateCreator) Parse(content []byte, baseDir, file string) (*HelmState,
 }
 
 // LoadEnvValues loads environment values files relative to the `baseDir`
-func (c *StateCreator) LoadEnvValues(target *HelmState, env string, ctxEnv *environment.Environment) (*HelmState, error) {
+func (c *StateCreator) LoadEnvValues(target *HelmState, env string, ctxEnv *environment.Environment, failOnMissingEnv bool) (*HelmState, error) {
 	state := *target
 
-	e, err := state.loadEnvValues(env, ctxEnv, c.readFile, c.glob)
+	e, err := state.loadEnvValues(env, failOnMissingEnv, ctxEnv, c.readFile, c.glob)
 	if err != nil {
 		return nil, &StateLoadError{fmt.Sprintf("failed to read %s", state.FilePath), err}
 	}
@@ -135,6 +135,7 @@ func (c *StateCreator) LoadEnvValues(target *HelmState, env string, ctxEnv *envi
 }
 
 // Parses YAML into HelmState, while loading environment values files relative to the `baseDir`
+// evaluateBases=true means that this is NOT a base helmfile
 func (c *StateCreator) ParseAndLoad(content []byte, baseDir, file string, envName string, evaluateBases bool, envValues *environment.Environment) (*HelmState, error) {
 	state, err := c.Parse(content, baseDir, file)
 	if err != nil {
@@ -145,14 +146,14 @@ func (c *StateCreator) ParseAndLoad(content []byte, baseDir, file string, envNam
 		if len(state.Bases) > 0 {
 			return nil, errors.New("nested `base` helmfile is unsupported. please submit a feature request if you need this!")
 		}
+	} else {
+		state, err = c.loadBases(envValues, state, baseDir)
+		if err != nil {
+			return nil, err
+		}
 	}
 
-	state, err = c.loadBases(envValues, state, baseDir)
+	state, err = c.LoadEnvValues(state, envName, envValues, evaluateBases)
-	if err != nil {
-		return nil, err
-	}
-
-	state, err = c.LoadEnvValues(state, envName, envValues)
 	if err != nil {
 		return nil, err
 	}
@@ -182,7 +183,7 @@ func (c *StateCreator) loadBases(envValues *environment.Environment, st *HelmSta
 	return layers[0], nil
 }
 
-func (st *HelmState) loadEnvValues(name string, ctxEnv *environment.Environment, readFile func(string) ([]byte, error), glob func(string) ([]string, error)) (*environment.Environment, error) {
+func (st *HelmState) loadEnvValues(name string, failOnMissingEnv bool, ctxEnv *environment.Environment, readFile func(string) ([]byte, error), glob func(string) ([]string, error)) (*environment.Environment, error) {
 	envVals := map[string]interface{}{}
 	envSpec, ok := st.Environments[name]
 	if ok {
@@ -210,7 +211,7 @@ func (st *HelmState) loadEnvValues(name string, ctxEnv *environment.Environment,
 				return nil, err
 			}
 		}
-	} else if ctxEnv == nil && name != DefaultEnv {
+	} else if ctxEnv == nil && name != DefaultEnv && failOnMissingEnv {
 		return nil, &UndefinedEnvError{msg: fmt.Sprintf("environment \"%s\" is not defined", name)}
 	}
 

pkg/state/create_test.go

@@ -20,7 +20,7 @@ func createFromYaml(content []byte, file string, env string, logger *zap.Sugared
 		abs:      filepath.Abs,
 		Strict:   true,
 	}
-	return c.ParseAndLoad(content, filepath.Dir(file), file, env, false, nil)
+	return c.ParseAndLoad(content, filepath.Dir(file), file, env, true, nil)
 }
 
 func TestReadFromYaml(t *testing.T) {
@@ -108,7 +108,7 @@ bar: {{ readFile "bar.txt" }}
 	})
 	testFs.Cwd = "/example/path/to"
 
-	state, err := NewCreator(logger, testFs.ReadFile, testFs.FileExists, testFs.Abs, testFs.Glob, nil, nil).ParseAndLoad(yamlContent, filepath.Dir(yamlFile), yamlFile, "production", false, nil)
+	state, err := NewCreator(logger, testFs.ReadFile, testFs.FileExists, testFs.Abs, testFs.Glob, nil, nil).ParseAndLoad(yamlContent, filepath.Dir(yamlFile), yamlFile, "production", true, nil)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}