k8s/cartservice: add init container to wait redis

otherwise nullpointerexception persists

Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

kubernetes-manifests/cartservice.yaml

@@ -8,6 +8,20 @@ spec:
       labels:
         app: cartservice
     spec:
+      terminationGracePeriodSeconds: 5
+      initContainers:
+      - name: wait-redis
+        image: redis:alpine
+        command: ['sh', '-c', 'set -x;
+          until timeout -t 5 redis-cli -h "${REDIS_HOST}" -p "${REDIS_PORT}" ping; do 
+            echo "waiting for redis at ${REDIS_HOST}:${REDIS_PORT}..."; 
+            sleep 2;
+          done;']
+        env:
+        - name: REDIS_HOST
+          value: "redis-cart"
+        - name: REDIS_PORT
+          value: "6379"
       containers:
       - name: server
         image: cartservice