Merge pull request #117 from Yolean/broker-init-pod-labler

Fix RBAC, set useful labels on broker pods from init script

Author: solsson

README.md

@@ -68,8 +68,6 @@ For clusters that enfoce [RBAC](https://kubernetes.io/docs/admin/authorization/r
 kubectl apply -f rbac-namespace-default/
 ```
 
-For example rack awareness can fail without this, `logs -c init-config` showing `Error from server (Forbidden): pods "kafka-0" is forbidden: User "system:serviceaccount:kafka:default" cannot get pods in the namespace "kafka": Unknown user "system:serviceaccount:kafka:default"`.
-
 ## Tests
 
 Tests are based on the [kube-test](https://github.com/Yolean/kube-test) concept.

kafka/10broker-config.yml

@@ -11,6 +11,8 @@ data:
     KAFKA_BROKER_ID=${HOSTNAME##*-}
     sed -i "s/#init#broker.id=#init#/broker.id=$KAFKA_BROKER_ID/" /etc/kafka/server.properties
 
+    LABELS="kafka-broker-id=$KAFKA_BROKER_ID"
+
     hash kubectl 2>/dev/null || {
       sed -i "s/#init#broker.rack=#init#/#init#broker.rack=# kubectl not found in path/" /etc/kafka/server.properties
     } && {
@@ -21,17 +23,20 @@ data:
         sed -i "s/#init#broker.rack=#init#/#init#broker.rack=# zone label not found for node $NODE_NAME/" /etc/kafka/server.properties
       else
         sed -i "s/#init#broker.rack=#init#/broker.rack=$ZONE/" /etc/kafka/server.properties
+        LABELS="$LABELS kafka-broker-rack=$ZONE"
       fi
 
-      # This requires additional RBAC, and won't be needed after https://github.com/kubernetes/kubernetes/pull/55329
-      kubectl -n $POD_NAMESPACE label pod $POD_NAME kafka-broker-id=$KAFKA_BROKER_ID
-
       OUTSIDE_HOST=$(kubectl get node "$NODE_NAME" -o jsonpath='{.status.addresses[?(@.type=="InternalIP")].address}')
       if [ $? -ne 0 ]; then
         echo "Outside (i.e. cluster-external access) host lookup command failed"
       else
-        OUTSIDE_HOST=${OUTSIDE_HOST}:3240${KAFKA_BROKER_ID}
-        sed -i "s|#init#advertised.listeners=OUTSIDE://#init#|advertised.listeners=OUTSIDE://${OUTSIDE_HOST}|" /etc/kafka/server.properties
+        OUTSIDE_PORT=3240${KAFKA_BROKER_ID}
+        sed -i "s|#init#advertised.listeners=OUTSIDE://#init#|advertised.listeners=OUTSIDE://${OUTSIDE_HOST}:${OUTSIDE_PORT}|" /etc/kafka/server.properties
+        LABELS="$LABELS kafka-listener-outside-host=$OUTSIDE_HOST kafka-listener-outside-port=$OUTSIDE_PORT"
+      fi
+
+      if [ ! -z "$LABELS" ]; then
+        kubectl -n $POD_NAMESPACE label pod $POD_NAME $LABELS || echo "Failed to label $POD_NAMESPACE.$POD_NAME - RBAC issue?"
       fi
     }
 

rbac-namespace-default/pod-labler.yml

@@ -0,0 +1,39 @@
+# To see if init containers need RBAC:
+#
+# $ kubectl -n kafka logs kafka-2 -c init-config
+# ...
+# Error from server (Forbidden): pods "kafka-2" is forbidden: User "system:serviceaccount:kafka:default" cannot get pods in the namespace "kafka": Unknown user "system:serviceaccount:kafka:default"
+#
+---
+kind: Role
+apiVersion: rbac.authorization.k8s.io/v1
+metadata:
+  name: pod-labler
+  namespace: kafka
+  labels:
+    origin: github.com_Yolean_kubernetes-kafka
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - pods
+  verbs:
+  - get
+  - update
+  - patch
+---
+kind: RoleBinding
+apiVersion: rbac.authorization.k8s.io/v1
+metadata:
+  name: kafka-pod-labler
+  namespace: kafka
+  labels:
+    origin: github.com_Yolean_kubernetes-kafka
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: pod-labler
+subjects:
+- kind: ServiceAccount
+  name: default
+  namespace: kafka