Make feature-flags config map name customizable

The config maps used by Tekton Pipeline should be able to take custom
names to avoid collisions with other services.

However, the feature-flags config map wasn't customizable because its
name hardcoded its usages.

By defining an env var in controller.yaml, from which the feature-flags
config map name can be derived, we enable it to be customizable.

Fixes #1805.

Author: Jerop Kipruto

config/controller.yaml

@@ -71,6 +71,8 @@ spec:
           value: config-artifact-bucket
         - name: CONFIG_ARTIFACT_PVC_NAME
           value: config-artifact-pvc
+        - name: CONFIG_FEATURE_FLAGS_NAME
+          value: feature-flags
         - name: METRICS_DOMAIN
           value: tekton.dev/pipeline
       volumes:

pkg/pod/pod.go

@@ -18,6 +18,7 @@ package pod
 
 import (
 	"fmt"
+	"os"
 	"path/filepath"
 
 	"github.com/tektoncd/pipeline/pkg/apis/pipeline"
@@ -31,13 +32,21 @@ import (
 	"k8s.io/client-go/kubernetes"
 )
 
+// GetFeatureFlagsConfigName returns the name of the configmap containing all
+// customizations for the feature flags.
+func GetFeatureFlagsConfigName() string {
+	if e := os.Getenv("CONFIG_FEATURE_FLAGS_NAME"); e != "" {
+		return e
+	}
+	return "feature-flags"
+}
+
 const (
 	homeDir = "/tekton/home"
 
 	// ResultsDir is the folder used by default to create the results file
 	ResultsDir = "/tekton/results"
 
-	featureFlagConfigMapName        = "feature-flags"
 	featureFlagDisableHomeEnvKey    = "disable-home-env-overwrite"
 	featureFlagDisableWorkingDirKey = "disable-working-directory-overwrite"
 
@@ -323,7 +332,7 @@ func getLimitRangeMinimum(namespace string, kubeclient kubernetes.Interface) (co
 //
 // For further reference see https://github.com/tektoncd/pipeline/issues/2013
 func ShouldOverrideHomeEnv(kubeclient kubernetes.Interface) bool {
-	configMap, err := kubeclient.CoreV1().ConfigMaps(system.GetNamespace()).Get(featureFlagConfigMapName, metav1.GetOptions{})
+	configMap, err := kubeclient.CoreV1().ConfigMaps(system.GetNamespace()).Get(GetFeatureFlagsConfigName(), metav1.GetOptions{})
 	if err == nil && configMap != nil && configMap.Data != nil && configMap.Data[featureFlagDisableHomeEnvKey] == "true" {
 		return false
 	}
@@ -337,7 +346,7 @@ func ShouldOverrideHomeEnv(kubeclient kubernetes.Interface) bool {
 //
 // For further reference see https://github.com/tektoncd/pipeline/issues/1836
 func shouldOverrideWorkingDir(kubeclient kubernetes.Interface) bool {
-	configMap, err := kubeclient.CoreV1().ConfigMaps(system.GetNamespace()).Get(featureFlagConfigMapName, metav1.GetOptions{})
+	configMap, err := kubeclient.CoreV1().ConfigMaps(system.GetNamespace()).Get(GetFeatureFlagsConfigName(), metav1.GetOptions{})
 	if err == nil && configMap != nil && configMap.Data != nil && configMap.Data[featureFlagDisableWorkingDirKey] == "true" {
 		return false
 	}

pkg/pod/pod_test.go

@@ -18,6 +18,7 @@ package pod
 
 import (
 	"fmt"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -813,14 +814,14 @@ func TestShouldOverrideHomeEnv(t *testing.T) {
 	}{{
 		description: "Default behaviour: A missing disable-home-env-overwrite flag should result in true",
 		configMap: &corev1.ConfigMap{
-			ObjectMeta: metav1.ObjectMeta{Name: featureFlagConfigMapName, Namespace: system.GetNamespace()},
+			ObjectMeta: metav1.ObjectMeta{Name: GetFeatureFlagsConfigName(), Namespace: system.GetNamespace()},
 			Data:       map[string]string{},
 		},
 		expected: true,
 	}, {
 		description: "Setting disable-home-env-overwrite to false should result in true",
 		configMap: &corev1.ConfigMap{
-			ObjectMeta: metav1.ObjectMeta{Name: featureFlagConfigMapName, Namespace: system.GetNamespace()},
+			ObjectMeta: metav1.ObjectMeta{Name: GetFeatureFlagsConfigName(), Namespace: system.GetNamespace()},
 			Data: map[string]string{
 				featureFlagDisableHomeEnvKey: "false",
 			},
@@ -829,7 +830,7 @@ func TestShouldOverrideHomeEnv(t *testing.T) {
 	}, {
 		description: "Setting disable-home-env-overwrite to true should result in false",
 		configMap: &corev1.ConfigMap{
-			ObjectMeta: metav1.ObjectMeta{Name: featureFlagConfigMapName, Namespace: system.GetNamespace()},
+			ObjectMeta: metav1.ObjectMeta{Name: GetFeatureFlagsConfigName(), Namespace: system.GetNamespace()},
 			Data: map[string]string{
 				featureFlagDisableHomeEnvKey: "true",
 			},
@@ -847,6 +848,37 @@ func TestShouldOverrideHomeEnv(t *testing.T) {
 	}
 }
 
+func TestGetFeatureFlagsConfigName(t *testing.T) {
+	for _, tc := range []struct {
+		description         string
+		featureFlagEnvValue string
+		expected            string
+	}{{
+		description:         "Feature flags config value not set",
+		featureFlagEnvValue: "",
+		expected:            "feature-flags",
+	}, {
+		description:         "Feature flags config value set",
+		featureFlagEnvValue: "feature-flags-test",
+		expected:            "feature-flags-test",
+	}} {
+		t.Run(tc.description, func(t *testing.T) {
+			original := os.Getenv("CONFIG_FEATURE_FLAGS_NAME")
+			defer t.Cleanup(func() {
+				os.Setenv("CONFIG_FEATURE_FLAGS_NAME", original)
+			})
+			if tc.featureFlagEnvValue != "" {
+				os.Setenv("CONFIG_FEATURE_FLAGS_NAME", tc.featureFlagEnvValue)
+			}
+			got := GetFeatureFlagsConfigName()
+			want := tc.expected
+			if got != want {
+				t.Errorf("GetFeatureFlagsConfigName() = %s, want %s", got, want)
+			}
+		})
+	}
+}
+
 func TestShouldOverrideWorkingDir(t *testing.T) {
 	for _, tc := range []struct {
 		description string
@@ -855,14 +887,14 @@ func TestShouldOverrideWorkingDir(t *testing.T) {
 	}{{
 		description: "Default behaviour: A missing disable-working-directory-overwrite flag should result in true",
 		configMap: &corev1.ConfigMap{
-			ObjectMeta: metav1.ObjectMeta{Name: featureFlagConfigMapName, Namespace: system.GetNamespace()},
+			ObjectMeta: metav1.ObjectMeta{Name: GetFeatureFlagsConfigName(), Namespace: system.GetNamespace()},
 			Data:       map[string]string{},
 		},
 		expected: true,
 	}, {
 		description: "Setting disable-working-directory-overwrite to false should result in true",
 		configMap: &corev1.ConfigMap{
-			ObjectMeta: metav1.ObjectMeta{Name: featureFlagConfigMapName, Namespace: system.GetNamespace()},
+			ObjectMeta: metav1.ObjectMeta{Name: GetFeatureFlagsConfigName(), Namespace: system.GetNamespace()},
 			Data: map[string]string{
 				featureFlagDisableWorkingDirKey: "false",
 			},
@@ -871,7 +903,7 @@ func TestShouldOverrideWorkingDir(t *testing.T) {
 	}, {
 		description: "Setting disable-working-directory-overwrite to true should result in false",
 		configMap: &corev1.ConfigMap{
-			ObjectMeta: metav1.ObjectMeta{Name: featureFlagConfigMapName, Namespace: system.GetNamespace()},
+			ObjectMeta: metav1.ObjectMeta{Name: GetFeatureFlagsConfigName(), Namespace: system.GetNamespace()},
 			Data: map[string]string{
 				featureFlagDisableWorkingDirKey: "true",
 			},