Implement clustering for Vertica datastore

[OpenStack Infra]

https://review.openstack.org/159566
commit c61a3bf5f90291d3bece56aef0432d4b7af03c27
Author: Sushil Kumar <email address hidden>
Date: Wed Mar 18 13:59:08 2015 +0000

    Implement clustering for Vertica datastore

    A specification for this change was submitted for review in
    https://review.openstack.org/#/c/151279

    - HP Vertica Community Edition supports upto a 3-node cluster.
    - HP Vertica requires a minimum of 3 nodes to achieve fault tolerance.
    - This patchset provides ability to launch HP Vertica 3-node cluster.
    - The cluster-show API, would also list the IPs of underlying instances.

    Code Added:
    - Added API strategy, taskmanager strategy, and guestagent strategy.
    - Included unit tests.

    Workflow for building Vertica cluster is as follows:
    - Guest instances are booted using new API strategy which then
      sends control to taskmanager strategy for further communication
      and guestagent API execution.
    - Once the guest instances are active in nova,
      they receive "prepare" message and following steps are performed:
        - Mount the data disk on device_path.
        - Check if vertica packages have been installed, install_if_needed().
        - Run Vertica pre-install test, prepare_for_install_vertica().
        - Get to a status BUILD_PENDING.
    - Cluster-Taskmanager strategy waits for all the instances
      in cluster to get to BUILD_PENDING state.
    - Once all instances in a cluster get to BUILD_PENDING state,
      taskmanager first, configures passwordless ssh for os-users(root, dbadmin)
      with the help of guestagent APIs get_keys and authroize_keys.
    - Once passwordless ssh has been configured, the taskmanager calls
      install_cluster guestagent API, which installs cluster on
      member instances and creates a database on the cluster.
    - Once this method finishes its job then taskmanager calls
      another guestagent API cluster_complete to
      notify cluster member of completion of cluster creation.

    New Files:
    - A new directory, vertica, has been created, for api, taskmanager,
      guestagent strategies under
      trove/common/strategies/cluster/experimental.
    - Unit-tests for cluster-controller, api and taskmanager code.

    DocImpact
    Change-Id: Ide30d1d2a136c7e638532a115db5ff5ab2a75e72
    Implements: blueprint implement-vertica-cluster

[Gauvain Pocentek (gpocentek)]

The options are in the config-ref.