innuendonh/docker-zk-exhibitor repository overview

Runs an Exhibitor⁠-managed ZooKeeper⁠ instance using S3 for backups and automatic node discovery.

Available on the Docker Index as mbabineau/zookeeper-exhibitor⁠:

docker pull mbabineau/zookeeper-exhibitor

⁠Versions

• Exhibitor 1.5.5
• ZooKeeper 3.4.6

⁠Usage

The container expects the following environment variables to be passed in:

• CONFIG_TYPE - the value to be passed to --configtype; accepts none, file, s3, zookeeper;
• HOSTNAME - addressable hostname for this node (Exhibitor will forward users of the UI to this address)
• HTTP_PROXY_HOST - (optional) HTTP Proxy hostname
• HTTP_PROXY_PORT - (optional) HTTP Proxy port
• HTTP_PROXY_USERNAME - (optional) HTTP Proxy username
• HTTP_PROXY_PASSWORD - (optional) HTTP Proxy password
• ZK_PASSWORD - (optional) the HTTP Basic Auth password for the "zk" user
• ZK_DATA_DIR - (optional) Zookeeper data directory
• ZK_LOG_DIR - (optional) Zookeeper log directory

Variables for config type s3:

• S3_BUCKET - (optional) bucket used by Exhibitor for backups and coordination
• S3_PREFIX - (optional) key prefix within S3_BUCKET to use for this cluster
• AWS_ACCESS_KEY_ID - (optional) AWS access key ID with read/write permissions on S3_BUCKET
• AWS_SECRET_ACCESS_KEY - (optional) secret key for AWS_ACCESS_KEY_ID
• AWS_REGION - (optional) the AWS region of the S3 bucket (defaults to us-west-2)

Variables for config type zookeeper:

• ZK_CONFIG_CONNECT - hostname and port of the zookeeper instance holding the shared config; passed to parameter --zkconfigconnect
• ZK_CONFIG_EXHIBITOR_PATH - (optional) defaults to /; passed to parameter --zkconfigexhibitorpath
• ZK_CONFIG_EXHIBITOR_PORT - (optional) defaults to 8181; passed to parameter --zkconfigexhibitorport

Starting the container:

docker run -p 8181:8181 -p 2181:2181 -p 2888:2888 -p 3888:3888 \
    -e S3_BUCKET=<bucket> \
    -e S3_PREFIX=<key_prefix> \
    -e AWS_ACCESS_KEY_ID=<access_key> \
    -e AWS_SECRET_ACCESS_KEY=<secret_key> \
    -e HOSTNAME=<host> \
    mbabineau/zookeeper-exhibitor:latest

Once the container is up, confirm Exhibitor is running:

$ curl -s localhost:8181/exhibitor/v1/cluster/status | python -m json.tool
[
    {
        "code": 3, 
        "description": "serving", 
        "hostname": "<host>", 
        "isLeader": true
    }
]

See Exhibitor's wiki⁠ for more details on its REST API.

You can also check Exhibitor's web UI at http://<host>:8181/exhibitor/v1/ui/index.html

Then confirm ZK is available:

$ echo ruok | nc <host> 2181
imok

⁠AWS IAM Policy

Exhibitor can also use an IAM Role attached to an instance instead of passing access or secret keys. This is an example policy that would be needed for the instance:

{
    "Statement": [
        {
            "Resource": [
                "arn:aws:s3:::exhibitor-bucket/*",
                "arn:aws:s3:::exhibitor-bucket"
            ],
            "Action": [
                "s3:AbortMultipartUpload",
                "s3:DeleteObject",
                "s3:GetBucketAcl",
                "s3:GetBucketPolicy",
                "s3:GetObject",
                "s3:GetObject",
                "s3:GetObjectAcl",
                "s3:ListBucket",
                "s3:ListBucketMultipartUploads",
                "s3:ListMultipartUploadParts",
                "s3:PutObject",
                "s3:PutObjectAcl"
            ],
            "Effect": "Allow"
        }
    ]
}

Starting the container:

docker run -p 8181:8181 -p 2181:2181 -p 2888:2888 -p 3888:3888 \
    -e S3_BUCKET=<bucket> \
    -e S3_PREFIX=<key_prefix> \
    -e HOSTNAME=<host> \
    mbabineau/zookeeper-exhibitor:latest