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kubernetesgoogle-kubernetes-enginekubernetes-statefulset

Is there any less hacky way of passing an Ordinal Index to StatefulSet environment variable?

I'm trying to run a zookeeper ensemble and am having an issue passing a unique ID as envrionment varible ZOO_MY_ID as required by official zookeeeper image found here.

I've tried reading about this and found similar overflow questions but none seems to be working.

kubernetes statefulsets index/ordinal exposed in template Is there a way to get ordinal index of a pod with in kubernetes statefulset configuration file?

For some reason, I am still seeing the ID for all servers to be the default id of 1

2019-05-24 01:38:31,648 [myid:1] - INFO  [QuorumPeer[myid=1]/0:0:0:0:0:0:0:0:2181:FastLeaderElection@847] - Notification time out: 60000
2019-05-24 01:38:31,649 [myid:1] - INFO  [WorkerSender[myid=1]:QuorumCnxManager@347] - Have smaller server identifier, so dropping the connection: (2, 1)
2019-05-24 01:38:31,649 [myid:1] - INFO  [WorkerReceiver[myid=1]:FastLeaderElection@595] - Notification: 1 (message format version), 1 (n.leader), 0x0 (n.zxid), 0x1 (n.round), LOOKING (n.state), 1 (n.sid), 0x0 (n.peerEpoch) LOOKING (my state)
2019-05-24 01:38:31,649 [myid:1] - INFO  [/0.0.0.0:3888:QuorumCnxManager$Listener@743] - Received connection request /10.24.1.64:37382
2019-05-24 01:38:31,650 [myid:1] - WARN  [RecvWorker:1:QuorumCnxManager$RecvWorker@1025] - Connection broken for id 1, my id = 1, error = 
java.io.EOFException
        at java.io.DataInputStream.readInt(DataInputStream.java:392)
        at org.apache.zookeeper.server.quorum.QuorumCnxManager$RecvWorker.run(QuorumCnxManager.java:1010)
2019-05-24 01:38:31,651 [myid:1] - WARN  [RecvWorker:1:QuorumCnxManager$RecvWorker@1028] - Interrupting SendWorker

Running the following command shows that no ID is passed however I am using the hacky way shown here: https://stackoverflow.com/a/48086813/5813215

kubectl exec -it zoo-2 -n kafka-dev printenv | grep "ZOO_"

ZOO_USER=zookeeper
ZOO_CONF_DIR=/conf
ZOO_DATA_DIR=/data
ZOO_DATA_LOG_DIR=/datalog
ZOO_LOG_DIR=/logs
ZOO_PORT=2181
ZOO_TICK_TIME=2000
ZOO_INIT_LIMIT=5
ZOO_SYNC_LIMIT=2
ZOO_AUTOPURGE_PURGEINTERVAL=0
ZOO_AUTOPURGE_SNAPRETAINCOUNT=3
ZOO_MAX_CLIENT_CNXNS=60
Solution

  • A cleaner solution is to use the ordinal number of the kubernetes. By default the ordinal number starts from 0. You can also set the starting number in V1.27 or later.

    env:
  - name: ZOO_MY_ID
    valueFrom:
      fieldRef:
        fieldPath: metadata.labels['apps.kubernetes.io/pod-index']