Make namespace configurable

README.md

@@ -40,7 +40,8 @@ This is what the output of another Pod's startup event would look like:
 ## Configuration
 The application is configurable via the environment variables:
 
-| Environment Variable | Description                                                      | Default Value |
-|:--------------------:|------------------------------------------------------------------|:-------------:|
-|          TZ          | Timezone of the logged event's timestamp (UTC for example)       |               |
-|      LOG_LEVEL       | The application's internal logging level (not related to events) |     INFO      |
+| Environment Variable | Description                                                                                                                                         | Default Value |
+|:--------------------:|-----------------------------------------------------------------------------------------------------------------------------------------------------|:-------------:|
+|          TZ          | Timezone of the logged event's timestamp (UTC for example)                                                                                          |      UTC      |
+|      NAMESPACE       | Namespace in which this application is running. If not set, tries to detect it automatically from the injected environment variable "POD_NAMESPACE" | event-logging |
+|      LOG_LEVEL       | The application's internal logging level (not related to events)                                                                                    |     INFO      |

persistence/timestamp_persister.go

@@ -6,11 +6,12 @@ import (
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
+	"os"
 	"strconv"
 	"time"
 )
 
-var namespace = "event-logging"
+var namespace string
 var timestampConfigMapName = "timestamp"
 
 type TimestampPersister struct {
@@ -22,6 +23,7 @@ type TimestampPersister struct {
 }
 
 func Init(client *kubernetes.Clientset, logger *logging.Logger) *TimestampPersister {
+	namespace = getConfiguredNamespace()
 	configMap, err := getConfigMap(client)
 	var currentTimestamp time.Time
 
@@ -59,6 +61,20 @@ func Init(client *kubernetes.Clientset, logger *logging.Logger) *TimestampPersis
 	return persister
 }
 
+// getConfiguredNamespace returns the namespace in which the ConfigMap should be updated.
+// It returns the value in the following priority order:
+// Environment variable "POD_NAMESPACE", Environment variable "NAMESPACE" or else "event-logging" by default
+func getConfiguredNamespace() string {
+	if podNamespace, isSet := os.LookupEnv("POD_NAMESPACE"); isSet {
+		return podNamespace
+	}
+	if namespace, isSet := os.LookupEnv("NAMESPACE"); isSet {
+		return namespace
+	}
+
+	return "event-logging"
+}
+
 func (s *TimestampPersister) runScheduledUpdates() {
 	for {
 		select {