Configuring the beacon agent
============================

TPA installs and configures the beacon agent on nodes which have the
role ``beacon-agent`` in ``config.yml`` . If ``--enable-beacon-agent``
is passed to ``tpaexec configure`` , then all of the postgres nodes in
the cluster have this role.

Beacon agent package version
----------------------------

By default, TPA installs the latest available version of
``beacon-agent`` .

The version of the ``beacon-agent`` package that is installed can be
specified by including ``beacon_agent_package_version: xxx`` under the
``cluster_vars`` section of the ``config.yml`` file.

.. code:: yaml

   cluster_vars:
       …
       beacon_agent_package_version: 1.56.2-1
       …

You may use any version specifier that apt or yum would accept.

If your version does not match, try appending a ``*`` wildcard. This is
often necessary when the package version has an epoch qualifier like
``2:...`` .

Beacon agent configuration
--------------------------

The beacon agent configuration contains two parameters which must be set
per-cluster, the access key and the project id.

The access key is kept encrypted in the cluster directory and can be set
or read using tpa’s ``store-password`` and ``show-password`` commands:

.. code:: bash

   $ tpaexec store-password . beacon_agent_access_key
   Password:

.. code:: bash

   $ tpaexec show-password . beacon_agent_access_key

If the environment variable BEACON_AGENT_ACCESS_KEY is set when
``tpaexec provision`` is run, the access key is set from its value.

The project id is stored in ``config.yml`` under the
``beacon_agent_project_id`` key in ``cluster_vars`` . If the
``--beacon_agent_project_id`` argument is passed to
``tpaexec configure`` then its value is written to ``config.yml``
appropriately.

Installing the beacon agent
---------------------------

TPA installs the beacon agent from EDB’s repositories and creates an
operating system user called ``beacon`` and a database user called
``beacon`` . A configuration file for the agent is written to
``.beacon/beacon_agent.yaml`` in the beacon user’s home directory.

Running the beacon agent
------------------------

TPA installs a systemd service unit file to start the agent at
boot-time, running as the beacon user.