helm: add NAMESPACE env var to EPP deployment for pool namespace fallback

Author: jyizheng

config/charts/inferencepool/values.yaml

@@ -6,7 +6,14 @@ inferenceExtension:
     tag: main
     pullPolicy: Always
   extProcPort: 9002
-  env: []
+  # Environment variables for the EPP container.
+  # The NAMESPACE variable is used as a fallback for the pool namespace if the --pool-namespace flag is not set.
+  # By default, this is set from the pod's metadata.namespace.
+  env:
+    - name: NAMESPACE
+      valueFrom:
+        fieldRef:
+          fieldPath: metadata.namespace
   pluginsConfigFile: "default-plugins.yaml"
   # Define additional container ports
   extraContainerPorts: []