piper: Use stageName from parametersJSON, log value and source (#1920)

stageName from parametersJSON was ignored up until now and there was a TODO in the code. The precedence from the TODO is not clear to me. It said "first env.STAGE_NAME, second: parametersJSON, third: flag". So maybe I implemented it wrongly, but it would be easy to change. Right now, STAGE_NAME is always in the ENV when piper is called from Jenkins, but to mimic the behavior of being able to pass `stageName` in the parameters and override the ENV value, this is what happens in go as well now.

The reason why `stageName` needs to be evaluated before other step parameters is that it affects config evaluation. So I've added a function which is called first in `PrepareConfig()`.

cmd/getConfig.go

@@ -33,6 +33,7 @@ func ConfigCommand() *cobra.Command {
 			path, _ := os.Getwd()
 			fatalHook := &log.FatalHook{CorrelationID: GeneralConfig.CorrelationID, Path: path}
 			log.RegisterHook(fatalHook)
+			initStageName(false)
 		},
 		Run: func(cmd *cobra.Command, _ []string) {
 			err := generateConfig()

cmd/piper.go

@@ -52,7 +52,6 @@ var rootCmd = &cobra.Command{
 This project 'Piper' binary provides a CI/CD step library.
 It contains many steps which can be used within CI/CD systems as well as directly on e.g. a developer's machine.
 `,
-	//ToDo: respect stageName to also come from parametersJSON -> first env.STAGE_NAME, second: parametersJSON, third: flag
 }
 
 // GeneralConfig contains global configuration flags for piper binary
@@ -113,7 +112,7 @@ func addRootFlags(rootCmd *cobra.Command) {
 	rootCmd.PersistentFlags().BoolVar(&GeneralConfig.IgnoreCustomDefaults, "ignoreCustomDefaults", false, "Disables evaluation of the parameter 'customDefaults' in the pipeline configuration file")
 	rootCmd.PersistentFlags().StringVar(&GeneralConfig.ParametersJSON, "parametersJSON", os.Getenv("PIPER_parametersJSON"), "Parameters to be considered in JSON format")
 	rootCmd.PersistentFlags().StringVar(&GeneralConfig.EnvRootPath, "envRootPath", ".pipeline", "Root path to Piper pipeline shared environments")
-	rootCmd.PersistentFlags().StringVar(&GeneralConfig.StageName, "stageName", os.Getenv("STAGE_NAME"), "Name of the stage for which configuration should be included")
+	rootCmd.PersistentFlags().StringVar(&GeneralConfig.StageName, "stageName", "", "Name of the stage for which configuration should be included")
 	rootCmd.PersistentFlags().StringVar(&GeneralConfig.StepConfigJSON, "stepConfigJSON", os.Getenv("PIPER_stepConfigJSON"), "Step configuration in JSON format")
 	rootCmd.PersistentFlags().BoolVar(&GeneralConfig.NoTelemetry, "noTelemetry", false, "Disables telemetry reporting")
 	rootCmd.PersistentFlags().BoolVarP(&GeneralConfig.Verbose, "verbose", "v", false, "verbose output")
@@ -121,9 +120,60 @@ func addRootFlags(rootCmd *cobra.Command) {
 
 }
 
+const stageNameEnvKey = "STAGE_NAME"
+
+// initStageName initializes GeneralConfig.StageName from either GeneralConfig.ParametersJSON
+// or the environment variable 'STAGE_NAME', unless it has been provided as command line option.
+// Log output needs to be suppressed via outputToLog by the getConfig step.
+func initStageName(outputToLog bool) {
+	var stageNameSource string
+	if outputToLog {
+		defer func() {
+			log.Entry().Infof("Using stageName '%s' from %s", GeneralConfig.StageName, stageNameSource)
+		}()
+	}
+
+	if GeneralConfig.StageName != "" {
+		// Means it was given as command line argument and has the highest precedence
+		stageNameSource = "command line arguments"
+		return
+	}
+
+	// Use stageName from ENV as fall-back, for when extracting it from parametersJSON fails below
+	GeneralConfig.StageName = os.Getenv(stageNameEnvKey)
+	stageNameSource = fmt.Sprintf("env variable '%s'", stageNameEnvKey)
+
+	if len(GeneralConfig.ParametersJSON) == 0 {
+		return
+	}
+
+	var params map[string]interface{}
+	err := json.Unmarshal([]byte(GeneralConfig.ParametersJSON), &params)
+	if err != nil {
+		if outputToLog {
+			log.Entry().Infof("Failed to extract 'stageName' from parametersJSON: %v", err)
+		}
+		return
+	}
+
+	stageName, hasKey := params["stageName"]
+	if !hasKey {
+		return
+	}
+
+	if stageNameString, ok := stageName.(string); ok && stageNameString != "" {
+		stageNameSource = "parametersJSON"
+		GeneralConfig.StageName = stageNameString
+	}
+}
+
 // PrepareConfig reads step configuration from various sources and merges it (defaults, config file, flags, ...)
 func PrepareConfig(cmd *cobra.Command, metadata *config.StepData, stepName string, options interface{}, openFile func(s string) (io.ReadCloser, error)) error {
 
+	log.SetFormatter(GeneralConfig.LogFormat)
+
+	initStageName(true)
+
 	filters := metadata.GetParameterFilters()
 
 	// add telemetry parameter "collectTelemetryData" to ALL, GENERAL and PARAMETER filters
@@ -138,8 +188,6 @@ func PrepareConfig(cmd *cobra.Command, metadata *config.StepData, stepName strin
 	var myConfig config.Config
 	var stepConfig config.StepConfig
 
-	log.SetFormatter(GeneralConfig.LogFormat)
-
 	if len(GeneralConfig.StepConfigJSON) != 0 {
 		// ignore config & defaults in favor of passed stepConfigJSON
 		stepConfig = config.GetStepConfigWithJSON(flagValues, GeneralConfig.StepConfigJSON, filters)

cmd/piper_test.go

@@ -31,6 +31,56 @@ func TestAddRootFlags(t *testing.T) {
 
 }
 
+func TestAdoptStageNameFromParametersJSON(t *testing.T) {
+	tt := []struct {
+		name          string
+		stageNameArg  string
+		stageNameEnv  string
+		stageNameJSON string
+	}{
+		{name: "no stage name", stageNameArg: "", stageNameEnv: "", stageNameJSON: ""},
+		{name: "stage name arg+env", stageNameArg: "arg", stageNameEnv: "env", stageNameJSON: "json"},
+		{name: "stage name env", stageNameArg: "", stageNameEnv: "env", stageNameJSON: "json"},
+		{name: "stage name json", stageNameArg: "", stageNameEnv: "", stageNameJSON: "json"},
+		{name: "stage name arg", stageNameArg: "arg", stageNameEnv: "", stageNameJSON: "json"},
+	}
+
+	for _, test := range tt {
+		t.Run(test.name, func(t *testing.T) {
+			// init
+			GeneralConfig.StageName = test.stageNameArg
+
+			resetValue := os.Getenv(stageNameEnvKey)
+			defer func() { _ = os.Setenv(stageNameEnvKey, resetValue) }()
+
+			err := os.Setenv(stageNameEnvKey, test.stageNameEnv)
+			if err != nil {
+				t.Fatalf("could not set env var %s", stageNameEnvKey)
+			}
+
+			if test.stageNameJSON != "" {
+				GeneralConfig.ParametersJSON = fmt.Sprintf("{\"stageName\":\"%s\"}", test.stageNameJSON)
+			} else {
+				GeneralConfig.ParametersJSON = "{}"
+			}
+			// test
+			initStageName(false)
+
+			// assert
+			// Order of if-clauses reflects wanted precedence.
+			if test.stageNameArg != "" {
+				assert.Equal(t, test.stageNameArg, GeneralConfig.StageName)
+			} else if test.stageNameJSON != "" {
+				assert.Equal(t, test.stageNameJSON, GeneralConfig.StageName)
+			} else if test.stageNameEnv != "" {
+				assert.Equal(t, test.stageNameEnv, GeneralConfig.StageName)
+			} else {
+				assert.Equal(t, "", GeneralConfig.StageName)
+			}
+		})
+	}
+}
+
 func TestPrepareConfig(t *testing.T) {
 	defaultsBak := GeneralConfig.DefaultConfig
 	GeneralConfig.DefaultConfig = []string{"testDefaults.yml"}
@@ -73,7 +123,7 @@ func TestPrepareConfig(t *testing.T) {
 			}
 
 			err := PrepareConfig(testCmd, &metadata, "testStep", &testOptions, mock.OpenFileMock)
-			assert.NoError(t, err, "no error expected but error occured")
+			assert.NoError(t, err, "no error expected but error occurred")
 
 			//assert config
 			assert.Equal(t, "testValue", testOptions.TestParam, "wrong value retrieved from config")
@@ -93,7 +143,7 @@ func TestPrepareConfig(t *testing.T) {
 			metadata := config.StepData{}
 
 			err := PrepareConfig(testCmd, &metadata, "testStep", &testOptions, mock.OpenFileMock)
-			assert.Error(t, err, "error expected but none occured")
+			assert.Error(t, err, "error expected but none occurred")
 		})
 	})
 }