zookeeper

Description

Get a Kafka cluster automated and manage its lifecycle with Juju and charms.

Usage

See config.yaml for the full list of options and descriptions.

Adding extra configurations

Kafka broker charms allows to append configurations to config files such as zookeeper.properties or service override.conf.

It is yaml-formatted list of key: value field. Can be added in a bundle with:

    zookeeper:
        charm: cs:zookeeper
        options:
            server-properties: |
                maxClientCnxns: 0
                initLimit: 5
                syncLimit: 2

Or using CLI, as for example:

    $ juju config kafka-broker server-properties="maxClientCnxns: 0
      initLimit: 5
      syncLimit: 2"

IMPORTANT: in case of a conflict between option OR charm's decision as for a relation, for example; the relation setup (i.e. the value defined by the charm for that given configuration) will be used instead of the value set in the option.

Certificate management

Zookeeper uses a keystore to contain the certificate and keys for TLS. Besides, it uses a truststore with all the trusted certificates for each unit. Each listener gets its own keystore / truststore.

To disable certificates, do the following steps:

1. Remove any ssl_* configs or certificates relation
2. if keystore is set to empty, certificates will not be used for that relation
3. case disabling certificates for peer relation, set sslQuorum: false

JMX Exporter support

Zookeeper's JVM can export information to Prometheus. Setup the integration with the following options:

    jmx_exporter_version: v0.12
    jmx_exporter_url: Maven's URL from where JMX jar can be downloaded.
        Format it to replace the versions.
    jmx-exporter-port: Port to be exposed by the exporter for prometheus.
    jmx_exporter_labels: comma-separated list of key=value tags.
    jmx_exporter_use_internal: use internal endpoint of Prometheus relation

The setup above will render the option in override.conf service:

    -javaagent:/opt/prometheus/jmx_prometheus_javaagent.jar=9409:/opt/prometheus/prometheus.yml

Nagios Integration

Set nagios_context config to allow NRPE integration to work. This option is used as a prefix for the check names and should change per environment.

Authentication with Kerberos

To set Kerberos, there are two steps that needs to be taken into consideration. First step, set the correct configuration on:

    kerberos-protocol
    kerberos-realm
    kerberos-domain
    kerberos-kdc-hostname
    kerberos-admin-hostname

Once the units are deployed, they will be blocked, waiting for the keytab file. That should be added per-unit, according to its hostname, using actions. Check the actions documentation for more details.

Developing

Create and activate a virtualenv with the development requirements:

virtualenv -p python3 venv
source venv/bin/activate
pip install -r requirements-dev.txt