Run zookeeper-statsd as the zookeeper user

We may as well align it with the other processes running on this system.

Change-Id: I6de0e5463b3dc66eae46a771d70d1d741527a35e

docker/zookeeper-statsd/Dockerfile

@@ -18,4 +18,17 @@ FROM docker.io/opendevorg/python-base:3.7
 
 COPY zookeeper-statsd.py /usr/local/bin
 RUN pip install statsd
+
+# 10001 is what we default to in our playbooks when deploying
+# zookeeper proper.
+RUN addgroup zookeeper --gid 10001 --system \
+  && adduser \
+    --system \
+    --uid 10001 \
+    --home /home/zookeeper \
+    --shell /bin/bash \
+    --ingroup zookeeper \
+    zookeeper
+
+USER 10001:10001
 CMD ["/usr/local/bin/zookeeper-statsd.py"]

playbooks/roles/zookeeper/files/zookeeper-compose/docker-compose.yaml

@@ -18,6 +18,7 @@ services:
     restart: always
     image: docker.io/opendevorg/zookeeper-statsd:latest
     network_mode: host
+    user: "10001:10001"
     environment:
       STATSD_HOST: graphite.opendev.org
       STATSD_PORT: 8125