A docker image for running ZooKeeper ensemble in Kubernetes.
latest/3.4.5-0.1.0 (ZooKeeper v3.4.5)
Naming convention for images is $ZK_VERSION-$KUBE_ZK_VERSION
0.1.0- initial release.
- based on ZooKeeper 3.4.5
The image supports the following ZooKeeper modes:
- Clustered
- Standalone
First, you need to be sure kube-dns is running in your kubernetes cluster. This image assumes each pod which consists of zookeeper ensemble can be resolved by Kubernetes' DNS.
# (1) create Headless Service to setup subdomain for zookeeper ensemble
$ kubectl create -f zookeeper.svc.yaml
# (2) start zookeeper ensemble which consists three pods in the example
$ kubectl create -f zookeeper.pod.yaml
To start the image in clustered mode you need to specify a couple of environment variables for the container.
| Environment Variable | Description |
|---|---|
| KUBE_ZK_MY_ID | The id of the server |
| KUBE_ZK_MAX_SERVERS | The number of servers in the ensemble |
| KUBE_ZK_HOSTNAME_PREFIX | The prefix of hostname(default: myid-). This must be matched with 'spec.hostname' in the pod definition. |
| KUBE_ZK_SUBDOMAIN | subdomain in which the ensemble lives. This must be matched with 'spec.subdomain' in the pod definition. |
| NAMESPACE | namespace in which the pod lives. |
| CLUSTER_DOMAIN | cluster domain of kubernetes cluster |
Each container started with all of the above variables will use the following env variable setup (for example, let KUBE_ZK_MAX_SERVERS=N, KUBE_ZK_HOSTNAME_PREFIX=myid-, KUBE_ZK_SUB_DOMAIN=zookeeper, NAMESPACE=default, CLUSTER_DOMAIN=cluster.local):
server.1=myid-1.zookeeper.default.svc.cluster.local:2888:3888
server.2=myid-2.zookeeper.default.svc.cluster.local:2888:3888
server.3=myid-3.zookeeper.default.svc.cluster.local:2888:3888
...
server.N=myid-N.zookeeper.default.svc.cluster.local:2888:3888
To start the image in standalone mode you can simply use:
kubectl run zk-standalone --image=everpeace/kube-zookeeper --quiet --rm -i --tty --restart=Never