Zookeeper in a Docker container

In this setup, the port configuration is:

• 2181 for client communication
• 2888 for peer servers
• 3888 for elections

They are currently not modifiable.

Environment Variables

The following variables control the configuration for the zookeeper process in the container. If ZK_CLUSTER_SIZE is not specified, a single node cluster is assumed.

• ZK_CLUSTER_SIZE - Number of instances in this Zookeeper ensemble
• ZK_SERVER_ID - Server ID of the node, must be between 1 and ZK_CLUSTER_SIZE
• ZK_MAX_SNAPSHOT_RETAIN_COUNT - Number of snapshots to retain (default 10)
• ZK_PURGE_INTERVAL - Snapshot purging interval in hours (default 24)
• ZK_SERVER_i_HOST - Hostname or IP of the server with ID "i" (replace the "i" with the ID of the corresponding server)

For example, the following configuration sets up a 3 node cluster:

ZK_CLUSTER_SIZE=3
ZK_SERVER_ID=1
ZK_SERVER_1_HOST=10.0.0.1
ZK_SERVER_2_HOST=10.0.0.2
ZK_SERVER_3_HOST=10.0.0.3

The above is the configuration for the container on 10.0.0.1. On 10.0.0.2 and 10.0.0.3, the ZK_SERVER_ID is 2 and 3 respectively. Other variables remain the same.

Volumes

The following volumes may be mounted on the host if desired (with no existing data on first startup):

• /var/lib/zookeeper - Zookeeper data directory
• /var/log/zookeeper - Zookeeper logs