Merge pull request #1094 from coetzeer/master

Add support for a prometheus postgres exporter
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Slavi Pantaleev 2021-05-28 08:42:46 +03:00 committed by GitHub
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10 changed files with 236 additions and 3 deletions

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@ -0,0 +1,29 @@
# Enabling metrics and graphs for Postgres (optional)
Expanding on the metrics exposed by the [syapse exporter and the node exporter](configuring-playbook-prometheus-grafana.md), the playbook enables the [postgres exporter](https://github.com/prometheus-community/postgres_exporter) that exposes more detailed information about what's happening on your postgres database.
You can enable this with the following settings in your configuration file (`inventory/host_vars/matrix.<your-domain>/vars.yml`):
```yaml
matrix_prometheus_postgres_exporter_enabled: true
# the role creates a postgres user as credential. You can configure these if required:
matrix_prometheus_postgres_exporter_database_username: 'matrix_prometheus_postgres_exporter'
matrix_prometheus_postgres_exporter_database_password: 'some-password'
```
## What does it do?
Name | Description
-----|----------
`matrix_prometheus_postgres_exporter_enabled`|Enable the postgres prometheus exporter. This sets up the docker container, connects it to the database and adds a 'job' to the prometheus config which tells prometheus about this new exporter. The default is 'false'
`matrix_prometheus_postgres_exporter_database_username`| The 'username' for the user that the exporter uses to connect to the database. The default is 'matrix_prometheus_postgres_exporter'
`matrix_prometheus_postgres_exporter_database_password`| The 'username' for the user that the exporter uses to connect to the database.
## More information
- [The PostgresSQL dashboard](https://grafana.com/grafana/dashboards/9628) (generic postgres dashboard)

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@ -1466,6 +1466,13 @@ matrix_postgres_additional_databases: |
'username': matrix_sygnal_database_username,
'password': matrix_sygnal_database_password,
}] if (matrix_sygnal_enabled and matrix_sygnal_database_engine == 'postgres' and matrix_sygnal_database_hostname == 'matrix-postgres') else [])
+
([{
'name': matrix_prometheus_postgres_exporter_database_name,
'username': matrix_prometheus_postgres_exporter_database_username,
'password': matrix_prometheus_postgres_exporter_database_password,
}] if (matrix_prometheus_postgres_exporter_enabled and matrix_prometheus_postgres_exporter_database_hostname == 'matrix-postgres') else [])
}}
matrix_postgres_import_roles_to_ignore: |
@ -1766,6 +1773,10 @@ matrix_prometheus_scraper_synapse_rules_synapse_tag: "{{ matrix_synapse_docker_i
matrix_prometheus_scraper_node_enabled: "{{ matrix_prometheus_node_exporter_enabled }}"
matrix_prometheus_scraper_node_targets: "{{ ['matrix-prometheus-node-exporter:9100'] if matrix_prometheus_node_exporter_enabled else [] }}"
matrix_prometheus_scraper_postgres_enabled: "{{ matrix_prometheus_postgres_exporter_enabled }}"
matrix_prometheus_scraper_postgres_targets: "{{ ['matrix-prometheus-postgres-exporter:'+ matrix_prometheus_postgres_exporter_port|string] if matrix_prometheus_scraper_postgres_enabled else [] }}"
######################################################################
#
# /matrix-prometheus
@ -1773,6 +1784,27 @@ matrix_prometheus_scraper_node_targets: "{{ ['matrix-prometheus-node-exporter:91
######################################################################
######################################################################
#
# matrix-prometheus-postgres-exporter
#
######################################################################
matrix_prometheus_postgres_exporter_enabled: false
matrix_prometheus_postgres_exporter_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'prometheus.pg.db') | to_uuid }}"
matrix_prometheus_postgres_exporter_systemd_required_services_list: |
{{
['docker.service']
+
(['matrix-postgres.service'] if matrix_postgres_enabled else [])
}}
######################################################################
#
# /matrix-prometheus-postgres-exporter
#
######################################################################
######################################################################
#
@ -1787,6 +1819,14 @@ matrix_grafana_enabled: false
# Grafana's HTTP port to the local host.
matrix_grafana_container_http_host_bind_port: "{{ '' if matrix_nginx_proxy_enabled else '127.0.0.1:3000' }}"
matrix_grafana_dashboard_download_urls_all: |
{{
matrix_grafana_dashboard_download_urls
+
(matrix_prometheus_postgres_exporter_dashboard_urls if matrix_prometheus_postgres_exporter_enabled else [])
}}
######################################################################
#
# /matrix-grafana

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@ -64,7 +64,7 @@
mode: 0440
owner: "{{ matrix_user_username }}"
group: "{{ matrix_user_groupname }}"
with_items: "{{ matrix_grafana_dashboard_download_urls }}"
with_items: "{{ matrix_grafana_dashboard_download_urls_all }}"
when: matrix_grafana_enabled|bool
- name: Ensure matrix-grafana.service installed

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# matrix-prometheus-postgres-exporter is an Prometheus exporter for postgres metrics
# See: https://github.com/prometheus-community/postgres_exporter
matrix_prometheus_postgres_exporter_enabled: false
matrix_prometheus_postgres_exporter_version: v0.9.0
matrix_prometheus_postgres_exporter_port: 9187
matrix_prometheus_postgres_exporter_docker_image: "quay.io/prometheuscommunity/postgres-exporter:{{ matrix_prometheus_postgres_exporter_version }}"
matrix_prometheus_postgres_exporter_docker_image_force_pull: "{{ matrix_prometheus_postgres_exporter_docker_image.endswith(':latest') }}"
# A list of extra arguments to pass to the container
matrix_prometheus_postgres_exporter_container_extra_arguments: ["-e PG_EXPORTER_AUTO_DISCOVER_DATABASES=true",
"-e PG_EXPORTER_WEB_LISTEN_ADDRESS=\":{{matrix_prometheus_postgres_exporter_port}}\"",
"-e DATA_SOURCE_NAME=\"postgresql://{{matrix_prometheus_postgres_exporter_database_username}}:{{matrix_prometheus_postgres_exporter_database_password}}@{{matrix_prometheus_postgres_exporter_database_hostname}}:5432/{{matrix_prometheus_postgres_exporter_database_name}}?sslmode=disable\"" ]
# List of systemd services that matrix-prometheus-postgres-exporter.service depends on
matrix_prometheus_postgres_exporter_systemd_required_services_list: ['docker.service']
# List of systemd services that matrix-prometheus-postgres-exporter.service wants
matrix_prometheus_postgres_exporter_systemd_wanted_services_list: []
# details for connecting to the database
matrix_prometheus_postgres_exporter_database_username: 'matrix_prometheus_postgres_exporter'
matrix_prometheus_postgres_exporter_database_password: 'some-password'
matrix_prometheus_postgres_exporter_database_hostname: 'matrix-postgres'
matrix_prometheus_postgres_exporter_database_port: 5432
matrix_prometheus_postgres_exporter_database_name: 'matrix_prometheus_postgres_exporter'
# Controls whether the matrix-prometheus container exposes its HTTP port (tcp/9100 in the container).
#
# Takes an "<ip>:<port>" value (e.g. "127.0.0.1:9100"), or empty string to not expose.
#
# Official recommendations are to run this container with `--net=host`,
# but we don't do that, since it:
# - likely exposes the metrics web server way too publicly (before applying https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1008)
# - or listens on a loopback interface only (--net=host and 127.0.0.1:9100), which is not reachable from another container (like `matrix-prometheus`)
#
# Using `--net=host` and binding to Docker's `matrix` bridge network may be a solution to both,
# but that's trickier to accomplish and won't necessarily work (hasn't been tested).
#
# Not using `--net=host` means that our network statistic reports are likely broken (inaccurate),
# because node-exporter can't see all interfaces, etc.
# For now, we'll live with that, until someone develops a better solution.
matrix_prometheus_postgres_exporter_container_http_host_bind_port: ''
matrix_prometheus_postgres_exporter_dashboard_urls:
- "https://grafana.com/api/dashboards/9628/revisions/7/download"

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@ -0,0 +1,5 @@
- set_fact:
matrix_systemd_services_list: "{{ matrix_systemd_services_list + ['matrix-prometheus-postgres-exporter.service'] }}"
when: matrix_prometheus_postgres_exporter_enabled|bool

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@ -0,0 +1,8 @@
- import_tasks: "{{ role_path }}/tasks/init.yml"
tags:
- always
- import_tasks: "{{ role_path }}/tasks/setup.yml"
tags:
- setup-all
- setup-prometheus-postgres-exporter

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@ -0,0 +1,54 @@
---
#
# Tasks related to setting up matrix-prometheus-postgres-exporter
#
- name: Ensure matrix-prometheus-postgres-exporter image is pulled
docker_image:
name: "{{ matrix_prometheus_postgres_exporter_docker_image }}"
source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
force_source: "{{ matrix_prometheus_postgres_exporter_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_prometheus_postgres_exporter_docker_image_force_pull }}"
when: "matrix_prometheus_postgres_exporter_enabled|bool"
- name: Ensure matrix-prometheus-postgres-exporter.service installed
template:
src: "{{ role_path }}/templates/systemd/matrix-prometheus-postgres-exporter.service.j2"
dest: "{{ matrix_systemd_path }}/matrix-prometheus-postgres-exporter.service"
mode: 0644
register: matrix_prometheus_postgres_exporter_systemd_service_result
when: matrix_prometheus_postgres_exporter_enabled|bool
- name: Ensure systemd reloaded after matrix-prometheus.service installation
service:
daemon_reload: yes
when: "matrix_prometheus_postgres_exporter_enabled|bool and matrix_prometheus_postgres_exporter_systemd_service_result.changed"
#
# Tasks related to getting rid of matrix-prometheus-postgres-exporter (if it was previously enabled)
#
- name: Check existence of matrix-prometheus-postgres-exporter service
stat:
path: "{{ matrix_systemd_path }}/matrix-prometheus-postgres-exporter.service"
register: matrix_prometheus_postgres_exporter_service_stat
- name: Ensure matrix-prometheus-postgres-exporter is stopped
service:
name: matrix-prometheus-postgres-exporter
state: stopped
daemon_reload: yes
register: stopping_result
when: "not matrix_prometheus_postgres_exporter_enabled|bool and matrix_prometheus_postgres_exporter_service_stat.stat.exists"
- name: Ensure matrix-prometheus-postgres-exporter.service doesn't exist
file:
path: "{{ matrix_systemd_path }}/matrix-prometheus-postgres-exporter.service"
state: absent
when: "not matrix_prometheus_postgres_exporter_enabled|bool and matrix_prometheus_postgres_exporter_service_stat.stat.exists"
- name: Ensure systemd reloaded after matrix-prometheus-postgres-exporter.service removal
service:
daemon_reload: yes
when: "not matrix_prometheus_postgres_exporter_enabled|bool and matrix_prometheus_postgres_exporter_service_stat.stat.exists"

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#jinja2: lstrip_blocks: "True"
[Unit]
Description=matrix-prometheus-postgres-exporter
{% for service in matrix_prometheus_postgres_exporter_systemd_required_services_list %}
Requires={{ service }}
After={{ service }}
{% endfor %}
{% for service in matrix_prometheus_postgres_exporter_systemd_wanted_services_list %}
Wants={{ service }}
{% endfor %}
DefaultDependencies=no
[Service]
Type=simple
Environment="HOME={{ matrix_systemd_unit_home_path }}"
ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-prometheus-postgres-exporter 2>/dev/null'
ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-prometheus-postgres-exporter 2>/dev/null'
ExecStart={{ matrix_host_command_docker }} run --rm --name matrix-prometheus-postgres-exporter \
--log-driver=none \
--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
--cap-drop=ALL \
--read-only \
{% for arg in matrix_prometheus_postgres_exporter_container_extra_arguments %}
{{ arg }} \
{% endfor %}
--network={{ matrix_docker_network }} \
{% if matrix_prometheus_postgres_exporter_container_http_host_bind_port %}
-p {{ matrix_prometheus_postgres_exporter_container_http_host_bind_port }}:{{matrix_prometheus_postgres_exporter_port}} \
{% endif %}
--pid=host \
{{ matrix_prometheus_postgres_exporter_docker_image }}
ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-prometheus-postgres-exporter 2>/dev/null'
ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-prometheus-postgres-exporter 2>/dev/null'
Restart=always
RestartSec=30
SyslogIdentifier=matrix-prometheus-postgres-exporter
[Install]
WantedBy=multi-user.target

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@ -38,3 +38,9 @@ scrape_configs:
static_configs:
- targets: {{ matrix_prometheus_scraper_node_targets|to_json }}
{% endif %}
{% if matrix_prometheus_scraper_postgres_enabled %}
- job_name: postgres
static_configs:
- targets: {{ matrix_prometheus_scraper_postgres_targets|to_json }}
{% endif %}

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@ -54,5 +54,5 @@
- matrix-coturn
- matrix-aux
- matrix-postgres-backup
- matrix-prometheus-postgres-exporter
- matrix-common-after