prometheus
==========

The present role :
  - installs prometheus server inside a Docker container
  - installs various prometheus exporter
    - node
    - blackbox
    - apache
    - varnish
    - php-fpm
    - opcache
    - redis
    - memcached
    - mysql
    - postgres
    - mongodb

Please note that Docker and Haproxy their own embedded exporters.
  - https://docs.docker.com/config/daemon/prometheus/
  - https://www.haproxy.com/fr/blog/haproxy-exposes-a-prometheus-metrics-endpoint/

The role has been successfully tested on :
  - Debian 9
  - Debian 10
  - Debian 11

Forced upgrade of installed exporters can be done by setting the extra parameters "exporter_upgrade" to "yes".

```
ansible-playbook playbook/myhost.yml -t prometheus -e "exporter_upgrade=yes"
```

Role variables
--------------

| Variable                                     | Type    | Choices                                                                            | Default                 | Comment         |
|----------------------------------------------|---------|------------------------------------------------------------------------------------|-------------------------|-----------------|
| prometheus_server_enable                     | string  | true / false                                                                       |                         |                 |
| prometheus_server_version                    | string  |                                                                                    |  latest                 |                 |
| prometheus_server_monitor                    | string  |                                                                                    |                         |                 |
| prometheus_server_global_scrape_interval     | string  |                                                                                    |  15                     |                 |
| prometheus_server_global_evaluation_interval | string  |                                                                                    |  15                     |                 |
| prometheus_server_job_name                   | string  |                                                                                    |  prometheus             |                 |
| prometheus_server_scrape_interval            | string  |                                                                                    |  5                      |                 |
| prometheus_server_scrape_timeout             | string  |                                                                                    |  5                      |                 |
| prometheus_exporter_packages                 | list    | node / mysqld / postgresql / mongodb / phpfpm / apache / haproxy / varnish / redis |                         |                 |
| prometheus_node_exporter_targets             | list    |                                                                                    |                         |                 |
| prometheus_mysqld_exporter_targets           | list    |                                                                                    |                         |                 |
| prometheus_mongodb_exporter_targets          | list    |                                                                                    |                         |                 |
| prometheus_postgres_exporter_targets         | list    |                                                                                    |                         |                 |
| prometheus_redis_exporter_targets            | list    |                                                                                    |                         |                 |
| prometheus_proxysql_exporter_targets         | list    |                                                                                    |                         | [Enable exporter](https://proxysql.com/documentation/prometheus-exporter/)  |
| prometheus_mysqld_exporter_user              | string  |                                                                                    |                         |                 |
| prometheus_mysqld_exporter_password          | string  |                                                                                    |                         |                 |
| prometheus_mongodb_exporter_host             | string  |                                                                                    | localhost               |                 |
| prometheus_mongodb_exporter_port             | string  |                                                                                    | 27017                   |                 |
| prometheus_mongodb_exporter_user             | string  |                                                                                    |                         |                 |
| prometheus_mongodb_exporter_pass             | string  |                                                                                    |                         |                 |
| prometheus_server_version                    | string  |                                                                                    |  latest                 |                 |
| prometheus_redis_exporter_addr               | string  |                                                                                    | redis://localhost:6379  |                 |
| prometheus_redis_exporter_user               | string  |                                                                                    |                         |                 |
| prometheus_redis_exporter_password           | string  |                                                                                    |                         |                 |

Dependencies
------------

  - jq
  - Docker must installed and running for prometheus server

Example Playbook
----------------

    - hosts: prometheus
      ignore_errors: "{{ ansible_check_mode }}" # ignore errors only in check mode !

      roles:
        - { role: brainsys.prometheus, tags: ['prometheus'] }

Example variables
-----------------

    ---
    prometheus_server_enable: 'true'
    prometheus_server_monitor: 'example'

    prometheus_exporter_packages:
      - node
      - mysqld

    prometheus_mysqld_exporter_user: 'foo'
    prometheus_mysqld_exporter_password: 'bar'

    prometheus_node_exporter_targets:
      - server01
      - server02

    prometheus_mysqld_exporter_targets:
      - server01

TODO
----

  - documentation
    - review / enhance documentation
  - memcached
    - add options to exporter launch
      - --memcached.address="localhost:11211"
      - --memcached.timeout=1s
      - --memcached.pid-file=""
    - handle multi instances for memcached exporter

License
-------

GPLv3

Author Information
------------------

Written by Ludovic Cartier <ludovic.cartier@brainsys.io>