This commit follows up the work in Kolla to provide deploy and configure the
Prometheus blackbox exporter.

An example blackbox-exporter module has been added (disabled by default)
called os_endpoint. This allows for the probing of endpoints over HTTP
and HTTPS. This can be used to monitor that OpenStack endpoints return a status
code of either 200 or 300, and the word 'versions' in the payload.

This change introduces a new variable `prometheus_blackbox_exporter_endpoints`.
Currently no defaults are specified because the configuration is heavily
dependent on the deployment.

Co-authored-by: Jack Heskett <Jack.Heskett@gresearch.co.uk>
Change-Id: I36ad4961078d90e2fd70c9a3368f5157d6fd89cd

Many tasks that use Docker have become specified already, but
not all. This change ensures all tasks that use the following
modules have become:

* kolla_docker
* kolla_ceph_keyring
* kolla_toolbox
* kolla_container_facts

It also adds become for 'command' tasks that use docker CLI.

Change-Id: I4a5ebcedaccb9261dbc958ec67e8077d7980e496

This patch implements the support for the elasticsearch-exporter in
kolla-ansible

The configuration and prechecks are reused from the other exporters

Depends-On: Id138f12e10102a6dd2cd8d84f2cc47aa29af3972
Change-Id: Iae0eac0179089f159804490bf71f1cf2c38dde54

This patch implements the initial support for the
openstack-exporter[0] in the kolla-ansible
prometheus monitoring system.

The configuration and prechecks are reused from the other
exporters and a new template is provided for generating
a os-client-config file required by the exporter.

The default scrape interval is 60 seconds, but it can
be extended via a configuration option.

[0] https://github.com/Linaro/openstack-exporter

Change-Id: I4a34c4bb56e74b5cd544972cbd6540d9acb6e4a1

Add missing `prometheus_memcached_exporter` container_fact
Fix conditional container_fact for haproxy_exporter

Change-Id: Id0f3b94af956f51e3c782c0244c6ce7a340119bd
Closes-Bug: #1808820

This patch extends the prometheus role for being able
to deploy the prometheus-alertmanager[0] container.

The variable enable_prometheus_alertmanager
decides if the container should be deployed and enabled.

If enabled, the following configuration and actions are performed:

- The alerting section on the prometheus-server configuration
is added pointing the prometheus-alertmanager host group as targets.

- HAProxy is configured to load-balance over the prometheus-alertmanager
host group. (external/internal).

Please note that a default (dummy) configuration is provided, that
allows the service to start, the operator should extend it via a node custom config

[0] https://github.com/openstack/kolla/tree/master/docker/prometheus/prometheus-alertmanager



Change-Id: I3a13342c67744a278cc8d52900a913c3ccc452ae
Closes-Bug: 1774725
Signed-off-by: Jorge Niedbalski <jorge.niedbalski@linaro.org>

cAdvisor (Container Advisor) provides metrics on resource usage and
performance characteristics of running containers.  This change
deploys a cadvisor container and configures prometheus to scrape
data from it.

Change-Id: I55dd4fee954f9be68efda397746861ddaaa0a565
Partially-Implements: blueprint prometheus

This patch adds the prometheus_memcached_exporter[0] to the
list of  available exporters, following the conventions
used by the previously integrated exporters.

[0] https://github.com/openstack/kolla/tree/master/docker/prometheus-memcached-exporter



Change-Id: I103b0ee19ef2fd17ce19a27d60773675ad234c1c
Closes-Bug: #1773303
Signed-off-by: Jorge Niedbalski <jorge.niedbalski@linaro.org>

the prometheus container is not exits, it should be
prometheus_server[0]

[0]: https://github.com/openstack/kolla-ansible/blob/master/ansible/roles/prometheus/defaults/main.yml#L6

Change-Id: Ib44390af9b8af5156dafbd0b0da6ae061a926ec7

This patch adds the ansible role to deploy the prometheus service which
can be used to collect performance metrics accross the environment

Partially-Implements: blueprint prometheus
Change-Id: I908b9c9dad63ab5c9b80be1e3a80a4fc8191cb9e