Merge pull request #838 from Peetz0r/stats

Prometheus and Grafana on stats.<domain>
2024-12-25 10:28:29 +01:00 · 2021-02-12 14:03:17 +02:00 · 2021-02-12 14:03:17 +02:00 · 2ac2b02cb4
commit 2ac2b02cb4
parent 11b310d259 890e4ad1af
34 changed files with 971 additions and 7 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -1,3 +1,12 @@
+# 2021-02-12
+
+## Monitoring/metrics support using Prometheus and Grafana
+
+Thanks to [@Peetz0r](https://github.com/Peetz0r), the playbook can now install a bunch of tools for monitoring your Matrix server: the [Prometheus](https://prometheus.io) time-series database server, the Prometheus [node-exporter](https://prometheus.io/docs/guides/node-exporter/) host metrics exporter, and the [Grafana](https://grafana.com/) web UI.
+
+To get get these installed, follow our [Enabling metrics and graphs (Prometheus, Grafana) for your Matrix server](docs/configuring-playbook-prometheus-grafana.md) docs page.
+
+
 # 2021-01-31

 ## Etherpad support
--- a/docs/configuring-dns.md
+++ b/docs/configuring-dns.md
@ -15,21 +15,25 @@ As we discuss in [Server Delegation](howto-server-delegation.md), there are 2 di
 This playbook mostly discusses the well-known file method, because it's easier to manage with regard to certificates.
 If you decide to go with the alternative method ([Server Delegation via a DNS SRV record (advanced)](howto-server-delegation.md#server-delegation-via-a-dns-srv-record-advanced)), please be aware that the general flow that this playbook guides you through may not match what you need to do.

-
-## General outline of DNS settings you need to do
+## Required DNS settings for services enabled by default

 | Type  | Host                         | Priority | Weight | Port | Target                 |
 | ----- | ---------------------------- | -------- | ------ | ---- | ---------------------- |
 | A     | `matrix`                     | -        | -      | -    | `matrix-server-IP`     |
 | CNAME | `element`                    | -        | -      | -    | `matrix.<your-domain>` |
-| CNAME | `dimension` (*)              | -        | -      | -    | `matrix.<your-domain>` |
-| CNAME | `jitsi` (*)                  | -        | -      | -    | `matrix.<your-domain>` |
 | SRV   | `_matrix-identity._tcp`      | 10       | 0      | 443  | `matrix.<your-domain>` |

+Be mindful as to how long it will take for the DNS records to propagate.

-DNS records marked with `(*)` above are optional. They refer to services that will not be installed by default (see the section below). If you won't be installing these services, feel free to skip creating these DNS records. Also be mindful as to how long it will take for the DNS records to propagate.
+If you are using Cloudflare DNS, make sure to disable the proxy and set all records to `DNS only`. Otherwise, fetching certificates will fail.

->  If you are using Cloudflare DNS, make sure to disable the proxy and set all records to `DNS only`. Otherwise, fetching certificates will fail.
+## Required DNS settings for optional services
+
+| Type  | Host                         | Priority | Weight | Port | Target                 |
+| ----- | ---------------------------- | -------- | ------ | ---- | ---------------------- |
+| CNAME | `dimension` (*)              | -        | -      | -    | `matrix.<your-domain>` |
+| CNAME | `jitsi` (*)                  | -        | -      | -    | `matrix.<your-domain>` |
+| CNAME | `stats` (*)                  | -        | -      | -    | `matrix.<your-domain>` |

 ## Subdomains setup

@ -42,6 +46,8 @@ The `dimension.<your-domain>` subdomain may be necessary, because this playbook

 The `jitsi.<your-domain>` subdomain may be necessary, because this playbook could install the [Jitsi video-conferencing platform](https://jitsi.org/) for you. Jitsi installation is disabled by default, because it may be heavy and is not a core required component. To learn how to install it, see our [Jitsi](configuring-playbook-jitsi.md) guide. If you do not wish to set up Jitsi, feel free to skip the `jitsi.<your-domain>` DNS record.

+The `stats.<your-domain>` subdomain may be necessary, because this playbook could install [Grafana](https://grafana.com/) and setup performance metrics for you. Grafana installation is disabled by default, it is not a core required component. To learn how to install it, see our [metrics and graphs guide](configuring-playbook-prometheus-grafana.md). If you do not wish to set up Grafana, feel free to skip the `stats.<your-domain>` DNS record. It is possible to install Prometheus without installing Grafana, this would also not require the `stats.<your-domain>` subdomain.
+

 ## `_matrix-identity._tcp` SRV record setup

--- a/docs/configuring-playbook-prometheus-grafana.md
+++ b/docs/configuring-playbook-prometheus-grafana.md
@ -0,0 +1,66 @@
+# Enabling metrics and graphs for your Matrix server (optional)
+
+It can be useful to have some (visual) insight into the performance of your homeserver.
+
+You can enable this with the following settings in your configuration file (`inventory/host_vars/matrix.<your-domain>/vars.yml`):
+
+```yaml
+matrix_prometheus_enabled: true
+
+matrix_prometheus_node_exporter_enabled: true
+
+matrix_grafana_enabled: true
+
+matrix_grafana_anonymous_access: false
+
+# This has no relation to your Matrix user id. It can be any username you'd like.
+# Changing the username subsequently won't work.
+matrix_grafana_default_admin_user: some_username_chosen_by_you
+
+# Passwords containing special characters may be troublesome.
+# Changing the password subsequently won't work.
+matrix_grafana_default_admin_password: some_strong_password_chosen_by_you
+```
+
+By default, a [Grafana](https://grafana.com/) web user-interface will be available at `https://stats.<your-domain>`.
+
+
+## What does it do?
+
+Name | Description
+-----|----------
+`matrix_prometheus_enabled`|[Prometheus](https://prometheus.io) is a time series database. It holds all the data we're going to talk about.
+`matrix_prometheus_node_exporter_enabled`|[Node Exporter](https://prometheus.io/docs/guides/node-exporter/) is an addon of sorts to Prometheus that collects generic system information such as CPU, memory, filesystem, and even system temperatures
+`matrix_grafana_enabled`|[Grafana](https://grafana.com/) is the visual component. It shows (on the `stats.<your-domain>` subdomain) the dashboards with the graphs that we're interested in
+`matrix_grafana_anonymous_access`|By default you need to log in to see graphs. If you want to publicly share your graphs (e.g. when asking for help in [`#synapse:matrix.org`](https://matrix.to/#/#synapse:matrix.org?via=matrix.org&via=privacytools.io&via=mozilla.org)) you'll want to enable this option.
+`matrix_grafana_default_admin_user`<br>`matrix_grafana_default_admin_password`|By default Grafana creates a user with `admin` as the username and password. If you feel this is insecure and you want to change it beforehand, you can do that here
+
+
+## Security and privacy
+
+Metrics and resulting graphs can contain a lot of information. This includes system specs but also usage patterns. This applies especially to small personal/family scale homeservers. Someone might be able to figure out when you wake up and go to sleep by looking at the graphs over time. Think about this before enabling anonymous access. And you should really not forget to change your Grafana password.
+
+Most of our docker containers run with limited system access, but the `prometheus-node-exporter` has access to the host network stack and (readonly) root filesystem. This is required to report on them. If you don't like that, you can set `matrix_prometheus_node_exporter_enabled: false` (which is actually the default). You will still get Synapse metrics with this container disabled. Both of the dashboards will always be enabled, so you can still look at historical data after disabling either source.
+
+
+## Collecting metrics to an external Prometheus server
+
+If you wish, you could expose homeserver metrics without enabling (installing) Prometheus and Grafana via the playbook. This may be useful for hooking Matrix services to an external Prometheus/Grafana installation.
+
+To do this, you may be interested in the following variables:
+
+Name | Description
+-----|----------
+`matrix_synapse_metrics_enabled`|Set this to `true` to make Synapse expose metrics (locally, on the container network)
+`matrix_nginx_proxy_proxy_synapse_metrics`|Set this to `true` to make matrix-nginx-proxy expose the Synapse metrics at `https://matrix.DOMAIN/_synapse/metrics`
+`matrix_nginx_proxy_proxy_synapse_metrics_basic_auth_enabled`|Set this to `true` to password-protect (using HTTP Basic Auth) `https://matrix.DOMAIN/_synapse/metrics` (the username is always `prometheus`, the password is defined in `matrix_nginx_proxy_proxy_synapse_metrics_basic_auth_key`)
+`matrix_nginx_proxy_proxy_synapse_metrics_basic_auth_key`|Set this to a password to use for HTTP Basic Auth for protecting `https://matrix.DOMAIN/_synapse/metrics` (the username is always `prometheus` - it's not configurable)
+
+
+## More inforation
+
+- [Understanding Synapse Performance Issues Through Grafana Graphs](https://github.com/matrix-org/synapse/wiki/Understanding-Synapse-Performance-Issues-Through-Grafana-Graphs) at the Synapse Github Wiki
+- [The Prometheus scraping rules](https://github.com/matrix-org/synapse/tree/master/contrib/prometheus) (we use v2)
+- [The Synapse Grafana dashboard](https://github.com/matrix-org/synapse/tree/master/contrib/grafana)
+- [The Node Exporter dashboard](https://github.com/rfrail3/grafana-dashboards) (for generic non-synapse performance graphs)
+
--- a/docs/configuring-playbook.md
+++ b/docs/configuring-playbook.md
@ -35,6 +35,8 @@ When you're done with all the configuration you'd like to do, continue with [Ins

 - [Setting up Dynamic DNS](configuring-playbook-dynamic-dns.md) (optional)

+- [Enabling metrics and graphs (Prometheus, Grafana) for your Matrix server](configuring-playbook-prometheus-grafana.md) (optional)
+
 ### Core service adjustments

 - [Configuring Synapse](configuring-playbook-synapse.md) (optional)
--- a/docs/container-images.md
+++ b/docs/container-images.md
@ -85,3 +85,9 @@ These services are not part of our default installation, but can be enabled by [
 - [anoa/matrix-reminder-bot](https://hub.docker.com/r/anoa/matrix-reminder-bot) - the [matrix-reminder-bot](https://github.com/anoadragon453/matrix-reminder-bot) bot for one-off & recurring reminders and alarms (optional)

 - [awesometechnologies/synapse-admin](https://hub.docker.com/r/awesometechnologies/synapse-admin) - the [synapse-admin](https://github.com/Awesome-Technologies/synapse-admin) web UI tool for administrating users and rooms on your Matrix server (optional)
+
+- [prom/prometheus](https://hub.docker.com/r/prom/prometheus/) - [Prometheus](https://github.com/prometheus/prometheus/) is a systems and service monitoring system
+
+- [prom/node-exporter](https://hub.docker.com/r/prom/node-exporter/) - [Prometheus Node Exporter](https://github.com/prometheus/node_exporter/) is an addon for Prometheus that gathers standard system metrics
+
+- [grafana/grafana](https://hub.docker.com/r/grafana/grafana/) - [Grafana](https://github.com/grafana/grafana/) is a graphing tool that works well with the above two images. Our playbook also adds two dashboards for [Synapse](https://github.com/matrix-org/synapse/tree/master/contrib/grafana) and  [Node Exporter](https://github.com/rfrail3/grafana-dashboards)
--- a/group_vars/matrix_servers
+++ b/group_vars/matrix_servers
@ -974,6 +974,7 @@ matrix_nginx_proxy_proxy_matrix_enabled: true
 matrix_nginx_proxy_proxy_element_enabled: "{{ matrix_client_element_enabled }}"
 matrix_nginx_proxy_proxy_dimension_enabled: "{{ matrix_dimension_enabled }}"
 matrix_nginx_proxy_proxy_jitsi_enabled: "{{ matrix_jitsi_enabled }}"
+matrix_nginx_proxy_proxy_grafana_enabled: "{{ matrix_grafana_enabled }}"

 matrix_nginx_proxy_proxy_matrix_corporal_api_enabled: "{{ matrix_corporal_enabled and matrix_corporal_http_api_enabled }}"
 matrix_nginx_proxy_proxy_matrix_corporal_api_addr_with_container: "matrix-corporal:41081"
@ -991,7 +992,10 @@ matrix_nginx_proxy_proxy_matrix_federation_api_addr_sans_container: "127.0.0.1:8

 matrix_nginx_proxy_container_federation_host_bind_port: "{{ matrix_federation_public_port }}"

-matrix_nginx_proxy_proxy_synapse_metrics: "{{ matrix_synapse_metrics_enabled }}"
+# This used to be hooked to `matrix_synapse_metrics_enabled`, but we don't do it anymore.
+# The fact that someone wishes to enable Synapse metrics does not necessarily mean they want to make them public.
+# A local Prometheus can consume them over the container network.
+matrix_nginx_proxy_proxy_synapse_metrics: false
 matrix_nginx_proxy_proxy_synapse_metrics_addr_with_container: "matrix-synapse:{{ matrix_synapse_metrics_port }}"
 matrix_nginx_proxy_proxy_synapse_metrics_addr_sans_container: "127.0.0.1:{{ matrix_synapse_metrics_port }}"

@ -1024,6 +1028,8 @@ matrix_ssl_domains_to_obtain_certificates_for: |
    +
    ([matrix_server_fqn_jitsi] if matrix_jitsi_enabled else [])
    +
+    ([matrix_server_fqn_grafana] if matrix_grafana_enabled else [])
+    +
    ([matrix_domain] if matrix_nginx_proxy_base_domain_serving_enabled else [])
  }}

@ -1297,6 +1303,9 @@ matrix_synapse_tls_private_key_path: ~

 matrix_synapse_federation_port_openid_resource_required: "{{ not matrix_synapse_federation_enabled and (matrix_dimension_enabled or matrix_ma1sd_enabled) }}"

+# If someone instals Prometheus via the playbook, they most likely wish to monitor Synapse.
+matrix_synapse_metrics_enabled: "{{ matrix_prometheus_enabled }}"
+
 matrix_synapse_email_enabled: "{{ matrix_mailer_enabled }}"
 matrix_synapse_email_smtp_host: "matrix-mailer"
 matrix_synapse_email_smtp_port: 8025
@ -1368,6 +1377,75 @@ matrix_synapse_admin_container_self_build: "{{ matrix_architecture != 'amd64' }}



+######################################################################
+#
+# matrix-prometheus-node-exporter
+#
+######################################################################
+
+matrix_prometheus_node_exporter_enabled: false
+
+# Normally, matrix-nginx-proxy is enabled and nginx can reach Prometheus Node Exporter over the container network.
+# If matrix-nginx-proxy is not enabled, or you otherwise have a need for it, you can expose
+# Prometheus' HTTP port to the local host.
+matrix_prometheus_node_exporter_container_http_host_bind_port: "{{ '' if matrix_nginx_proxy_enabled else '127.0.0.1:9100' }}"
+
+######################################################################
+#
+# /matrix-prometheus-node-exporter
+#
+######################################################################
+
+
+
+######################################################################
+#
+# matrix-prometheus
+#
+######################################################################
+
+matrix_prometheus_enabled: false
+
+# Normally, matrix-nginx-proxy is enabled and nginx can reach Prometheus over the container network.
+# If matrix-nginx-proxy is not enabled, or you otherwise have a need for it, you can expose
+# Prometheus' HTTP port to the local host.
+matrix_prometheus_container_http_host_bind_port: "{{ '' if matrix_nginx_proxy_enabled else '127.0.0.1:9090' }}"
+
+matrix_prometheus_scraper_synapse_enabled: "{{ matrix_synapse_enabled and matrix_synapse_metrics_enabled }}"
+matrix_prometheus_scraper_synapse_targets: ['matrix-synapse:{{ matrix_synapse_metrics_port }}']
+matrix_prometheus_scraper_synapse_rules_synapse_tag: "{{ matrix_synapse_docker_image_tag }}"
+
+matrix_prometheus_scraper_node_enabled: "{{ matrix_prometheus_node_exporter_enabled }}"
+
+######################################################################
+#
+# /matrix-prometheus
+#
+######################################################################
+
+
+
+######################################################################
+#
+# matrix-grafana
+#
+######################################################################
+
+matrix_grafana_enabled: false
+
+# Normally, matrix-nginx-proxy is enabled and nginx can reach Grafana over the container network.
+# If matrix-nginx-proxy is not enabled, or you otherwise have a need for it, you can expose
+# 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
+#
+######################################################################
+
+
+
 ######################################################################
 #
 # matrix-registration
--- a/roles/matrix-base/defaults/main.yml
+++ b/roles/matrix-base/defaults/main.yml
@ -21,6 +21,9 @@ matrix_server_fqn_dimension: "dimension.{{ matrix_domain }}"
 # This is where you access Jitsi.
 matrix_server_fqn_jitsi: "jitsi.{{ matrix_domain }}"

+# This is where you access Grafana.
+matrix_server_fqn_grafana: "stats.{{ matrix_domain }}"
+
 matrix_federation_public_port: 8448

 # The architecture that your server runs.
--- a/roles/matrix-grafana/defaults/main.yml
+++ b/roles/matrix-grafana/defaults/main.yml
@ -0,0 +1,47 @@
+# matrix-grafana is open source visualization and analytics software
+# See: https://github.com/matrix-org/synapse/blob/master/docs/metrics-howto.md
+
+matrix_grafana_enabled: false
+
+matrix_grafana_docker_image: "docker.io/grafana/grafana:7.4.0"
+matrix_grafana_docker_image_force_pull: "{{ matrix_grafana_docker_image.endswith(':latest') }}"
+
+# Not conditional, because when someone disables metrics
+# they might still want to look at the old existing data.
+# So it would be silly to delete the dashboard in such case.
+matrix_grafana_dashboard_download_urls:
+- "https://raw.githubusercontent.com/matrix-org/synapse/master/contrib/grafana/synapse.json"
+- "https://raw.githubusercontent.com/rfrail3/grafana-dashboards/master/prometheus/node-exporter-full.json"
+
+matrix_grafana_base_path: "{{ matrix_base_data_path }}/grafana"
+matrix_grafana_config_path: "{{ matrix_grafana_base_path }}/config"
+matrix_grafana_data_path: "{{ matrix_grafana_base_path }}/data"
+
+# Allow viewing Grafana without logging in
+matrix_grafana_anonymous_access: false
+
+# specify organization name that should be used for unauthenticated users
+# if you change this in the Grafana admin panel, this needs to be updated
+# to match to keep anonymous logins working
+matrix_grafana_anonymous_access_org_name: 'Main Org.'
+
+
+# default admin credentials, you are asked to change these on first login
+matrix_grafana_default_admin_user: admin
+matrix_grafana_default_admin_password: admin
+
+# A list of extra arguments to pass to the container
+matrix_grafana_container_extra_arguments: []
+
+# List of systemd services that matrix-grafana.service depends on
+matrix_grafana_systemd_required_services_list: ['docker.service']
+
+# List of systemd services that matrix-grafana.service wants
+matrix_grafana_systemd_wanted_services_list: []
+
+# Controls whether the matrix-grafana container exposes its HTTP port (tcp/3000 in the container).
+#
+# Takes an "<ip>:<port>" or "<port>" value (e.g. "127.0.0.1:3000"), or empty string to not expose.
+matrix_grafana_container_http_host_bind_port: ''
+
+
--- a/roles/matrix-grafana/tasks/init.yml
+++ b/roles/matrix-grafana/tasks/init.yml
@ -0,0 +1,5 @@
+- set_fact:
+    matrix_systemd_services_list: "{{ matrix_systemd_services_list + ['matrix-grafana.service'] }}"
+  when: matrix_grafana_enabled|bool
+
+
--- a/roles/matrix-grafana/tasks/main.yml
+++ b/roles/matrix-grafana/tasks/main.yml
@ -0,0 +1,14 @@
+- import_tasks: "{{ role_path }}/tasks/init.yml"
+  tags:
+    - always
+
+- import_tasks: "{{ role_path }}/tasks/validate_config.yml"
+  when: run_setup|bool
+  tags:
+    - setup-all
+    - setup-grafana
+
+- import_tasks: "{{ role_path }}/tasks/setup.yml"
+  tags:
+    - setup-all
+    - setup-grafana
--- a/roles/matrix-grafana/tasks/setup.yml
+++ b/roles/matrix-grafana/tasks/setup.yml
@ -0,0 +1,115 @@
+---
+
+#
+# Tasks related to setting up matrix-grafana
+#
+
+- name: Ensure matrix-grafana image is pulled
+  docker_image:
+    name: "{{ matrix_grafana_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_grafana_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_grafana_docker_image_force_pull }}"
+  when: "matrix_grafana_enabled|bool"
+
+- name: Ensure grafana paths exists
+  file:
+    path: "{{ item }}"
+    state: directory
+    mode: 0750
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  with_items:
+    - "{{ matrix_grafana_base_path }}"
+    - "{{ matrix_grafana_config_path }}"
+    - "{{ matrix_grafana_config_path }}/provisioning"
+    - "{{ matrix_grafana_config_path }}/provisioning/datasources"
+    - "{{ matrix_grafana_config_path }}/provisioning/dashboards"
+    - "{{ matrix_grafana_config_path }}/dashboards"
+    - "{{ matrix_grafana_data_path }}"
+  when: matrix_grafana_enabled|bool
+  
+- name: Ensure grafana.ini present
+  template:
+    src: "{{ role_path }}/templates/grafana.ini.j2"
+    dest: "{{ matrix_grafana_config_path }}/grafana.ini"
+    mode: 0440
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  when: matrix_grafana_enabled|bool
+  
+- name: Ensure provisioning/datasources/default.yaml present
+  template:
+    src: "{{ role_path }}/templates/datasources.yaml.j2"
+    dest: "{{ matrix_grafana_config_path }}/provisioning/datasources/default.yaml"
+    mode: 0440
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  when: matrix_grafana_enabled|bool
+  
+- name: Ensure provisioning/dashboards/default.yaml present
+  template:
+    src: "{{ role_path }}/templates/dashboards.yaml.j2"
+    dest: "{{ matrix_grafana_config_path }}/provisioning/dashboards/default.yaml"
+    mode: 0440
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  when: matrix_grafana_enabled|bool
+  
+- name: Ensure dashboard(s) downloaded
+  get_url:
+    url: "{{ item }}"
+    dest: "{{ matrix_grafana_config_path }}/dashboards/"
+    force: true
+    mode: 0440
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  with_items: "{{ matrix_grafana_dashboard_download_urls }}"
+  when: matrix_grafana_enabled|bool
+
+- name: Ensure matrix-grafana.service installed
+  template:
+    src: "{{ role_path }}/templates/systemd/matrix-grafana.service.j2"
+    dest: "{{ matrix_systemd_path }}/matrix-grafana.service"
+    mode: 0644
+  register: matrix_grafana_systemd_service_result
+  when: matrix_grafana_enabled|bool
+
+- name: Ensure systemd reloaded after matrix-grafana.service installation
+  service:
+    daemon_reload: yes
+  when: "matrix_grafana_enabled|bool and matrix_grafana_systemd_service_result.changed"
+
+#
+# Tasks related to getting rid of matrix-grafana (if it was previously enabled)
+#
+
+- name: Check existence of matrix-grafana service
+  stat:
+    path: "{{ matrix_systemd_path }}/matrix-grafana.service"
+  register: matrix_grafana_service_stat
+
+- name: Ensure matrix-grafana is stopped
+  service:
+    name: matrix-grafana
+    state: stopped
+    daemon_reload: yes
+  register: stopping_result
+  when: "not matrix_grafana_enabled|bool and matrix_grafana_service_stat.stat.exists"
+
+- name: Ensure matrix-grafana.service doesn't exist
+  file:
+    path: "{{ matrix_systemd_path }}/matrix-grafana.service"
+    state: absent
+  when: "not matrix_grafana_enabled|bool and matrix_grafana_service_stat.stat.exists"
+
+- name: Ensure systemd reloaded after matrix-grafana.service removal
+  service:
+    daemon_reload: yes
+  when: "not matrix_grafana_enabled|bool and matrix_grafana_service_stat.stat.exists"
+
+- name: Ensure matrix-grafana Docker image doesn't exist
+  docker_image:
+    name: "{{ matrix_grafana_docker_image }}"
+    state: absent
+  when: "not matrix_grafana_enabled|bool"
--- a/roles/matrix-grafana/tasks/validate_config.yml
+++ b/roles/matrix-grafana/tasks/validate_config.yml
@ -0,0 +1,7 @@
+---
+
+- name: Fail if Prometheus not enabled
+  fail:
+    msg: >
+      You need to enable `matrix_prometheus_enabled` to use Prometheus as data source for Grafana.
+  when: "not matrix_prometheus_enabled"
--- a/roles/matrix-grafana/templates/dashboards.yaml.j2
+++ b/roles/matrix-grafana/templates/dashboards.yaml.j2
@ -0,0 +1,9 @@
+apiVersion: 1
+
+providers:
+  - name: {{ matrix_server_fqn_matrix }} - Dashboards
+    folder: '' # The folder where to place the dashboards
+    type: file
+    allowUiUpdates: true
+    options:
+      path: /etc/grafana/dashboards
--- a/roles/matrix-grafana/templates/datasources.yaml.j2
+++ b/roles/matrix-grafana/templates/datasources.yaml.j2
@ -0,0 +1,8 @@
+apiVersion: 1
+
+datasources:
+  - name: {{ matrix_server_fqn_matrix }} - Prometheus
+    type: prometheus
+    # Access mode - proxy (server in the UI) or direct (browser in the UI).
+    access: proxy
+    url: http://matrix-prometheus:9090
--- a/roles/matrix-grafana/templates/grafana.ini.j2
+++ b/roles/matrix-grafana/templates/grafana.ini.j2
@ -0,0 +1,20 @@
+[security]
+# default admin user, created on startup
+admin_user = {{ matrix_grafana_default_admin_user }}
+
+# default admin password, can be changed before first start of grafana,  or in profile settings
+admin_password = {{ matrix_grafana_default_admin_password }}
+
+[auth.anonymous]
+# enable anonymous access
+enabled = {{ matrix_grafana_anonymous_access }}
+
+# specify organization name that should be used for unauthenticated users
+org_name = {{ matrix_grafana_anonymous_access_org_name }}
+
+[dashboards]
+{% if matrix_synapse_metrics_enabled %}
+default_home_dashboard_path = /etc/grafana/dashboards/synapse.json
+{% else %}
+default_home_dashboard_path = /etc/grafana/dashboards/node-exporter-full.json
+{% endif %}
--- a/roles/matrix-grafana/templates/systemd/matrix-grafana.service.j2
+++ b/roles/matrix-grafana/templates/systemd/matrix-grafana.service.j2
@ -0,0 +1,43 @@
+#jinja2: lstrip_blocks: "True"
+[Unit]
+Description=matrix-grafana
+{% for service in matrix_grafana_systemd_required_services_list %}
+Requires={{ service }}
+After={{ service }}
+{% endfor %}
+{% for service in matrix_grafana_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-grafana 2>/dev/null'
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-grafana 2>/dev/null'
+
+
+ExecStart={{ matrix_host_command_docker }} run --rm --name matrix-grafana \
+			--log-driver=none \
+			--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
+			--cap-drop=ALL \
+			--read-only \
+			--network={{ matrix_docker_network }} \
+			{% if matrix_grafana_container_http_host_bind_port %}
+			-p {{ matrix_grafana_container_http_host_bind_port }}:3000 \
+			{% endif %}
+			-v {{ matrix_grafana_config_path }}:/etc/grafana:z \
+			-v {{ matrix_grafana_data_path }}:/var/lib/grafana:z \
+			{% for arg in matrix_grafana_container_extra_arguments %}
+			{{ arg }} \
+			{% endfor %}
+			{{ matrix_grafana_docker_image }}
+
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-grafana 2>/dev/null'
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-grafana 2>/dev/null'
+Restart=always
+RestartSec=30
+SyslogIdentifier=matrix-grafana
+
+[Install]
+WantedBy=multi-user.target
--- a/roles/matrix-nginx-proxy/defaults/main.yml
+++ b/roles/matrix-nginx-proxy/defaults/main.yml
@ -115,6 +115,10 @@ matrix_nginx_proxy_proxy_dimension_hostname: "{{ matrix_server_fqn_dimension }}"
 matrix_nginx_proxy_proxy_jitsi_enabled: false
 matrix_nginx_proxy_proxy_jitsi_hostname: "{{ matrix_server_fqn_jitsi }}"

+# Controls whether proxying the grafana domain should be done.
+matrix_nginx_proxy_proxy_grafana_enabled: false
+matrix_nginx_proxy_proxy_grafana_hostname: "{{ matrix_server_fqn_grafana }}"
+
 # Controls whether proxying for the matrix-corporal API (`/_matrix/corporal`) should be done (on the matrix domain)
 matrix_nginx_proxy_proxy_matrix_corporal_api_enabled: false
 matrix_nginx_proxy_proxy_matrix_corporal_api_addr_with_container: "matrix-corporal:41081"
@ -212,6 +216,9 @@ matrix_nginx_proxy_proxy_dimension_additional_server_configuration_blocks: []
 # A list of strings containing additional configuration blocks to add to Jitsi's server configuration.
 matrix_nginx_proxy_proxy_jitsi_additional_server_configuration_blocks: []

+# A list of strings containing additional configuration blocks to add to Grafana's server configuration.
+matrix_nginx_proxy_proxy_grafana_additional_server_configuration_blocks: []
+
 # A list of strings containing additional configuration blocks to add to the base domain server configuration.
 matrix_nginx_proxy_proxy_domain_additional_server_configuration_blocks: []

--- a/roles/matrix-nginx-proxy/tasks/setup_nginx_proxy.yml
+++ b/roles/matrix-nginx-proxy/tasks/setup_nginx_proxy.yml
@ -80,6 +80,13 @@
    mode: 0644
  when: matrix_nginx_proxy_proxy_jitsi_enabled|bool

+- name: Ensure Matrix nginx-proxy configuration for grafana domain exists
+  template:
+    src: "{{ role_path }}/templates/nginx/conf.d/matrix-grafana.conf.j2"
+    dest: "{{ matrix_nginx_proxy_confd_path }}/matrix-grafana.conf"
+    mode: 0644
+  when: matrix_nginx_proxy_proxy_grafana_enabled|bool
+
 - name: Ensure Matrix nginx-proxy data directory for base domain exists
  file:
    path: "{{ matrix_nginx_proxy_data_path }}/matrix-domain"
@ -183,6 +190,12 @@
    state: absent
  when: "not matrix_nginx_proxy_proxy_jitsi_enabled|bool"

+- name: Ensure Matrix nginx-proxy configuration for grafana domain deleted
+  file:
+    path: "{{ matrix_nginx_proxy_confd_path }}/matrix-grafana.conf"
+    state: absent
+  when: "not matrix_nginx_proxy_proxy_grafana_enabled|bool"
+
 - name: Ensure Matrix nginx-proxy homepage for base domain deleted
  file:
    path: "{{ matrix_nginx_proxy_data_path }}/matrix-domain/index.html"
--- a/roles/matrix-nginx-proxy/templates/nginx/conf.d/matrix-grafana.conf.j2
+++ b/roles/matrix-nginx-proxy/templates/nginx/conf.d/matrix-grafana.conf.j2
@ -0,0 +1,79 @@
+#jinja2: lstrip_blocks: "True"
+
+{% macro render_vhost_directives() %}
+	gzip on;
+	gzip_types text/plain application/json application/javascript text/css image/x-icon font/ttf image/gif;
+	add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+	add_header X-Content-Type-Options nosniff;
+	add_header X-Frame-Options SAMEORIGIN;
+	{% for configuration_block in matrix_nginx_proxy_proxy_grafana_additional_server_configuration_blocks %}
+		{{- configuration_block }}
+	{% endfor %}
+
+	location / {
+		{% if matrix_nginx_proxy_enabled %}
+			{# Use the embedded DNS resolver in Docker containers to discover the service #}
+			resolver 127.0.0.11 valid=5s;
+			set $backend "matrix-grafana:3000";
+			proxy_pass http://$backend;
+		{% else %}
+			{# Generic configuration for use outside of our container setup #}
+			proxy_pass http://127.0.0.1:3000;
+		{% endif %}
+
+		proxy_set_header Host $host;
+		proxy_set_header X-Forwarded-For $remote_addr;
+	}
+{% endmacro %}
+
+server {
+	listen {{ 8080 if matrix_nginx_proxy_enabled else 80 }};
+
+	server_name {{ matrix_nginx_proxy_proxy_grafana_hostname }};
+
+	server_tokens off;
+	root /dev/null;
+
+	{% if matrix_nginx_proxy_https_enabled %}
+		location /.well-known/acme-challenge {
+			{% if matrix_nginx_proxy_enabled %}
+				{# Use the embedded DNS resolver in Docker containers to discover the service #}
+				resolver 127.0.0.11 valid=5s;
+				set $backend "matrix-certbot:8080";
+				proxy_pass http://$backend;
+			{% else %}
+				{# Generic configuration for use outside of our container setup #}
+				proxy_pass http://127.0.0.1:{{ matrix_ssl_lets_encrypt_certbot_standalone_http_port }};
+			{% endif %}
+		}
+
+		location / {
+			return 301 https://$http_host$request_uri;
+		}
+	{% else %}
+		{{ render_vhost_directives() }}
+	{% endif %}
+}
+
+{% if matrix_nginx_proxy_https_enabled %}
+server {
+	listen {{ 8443 if matrix_nginx_proxy_enabled else 443 }} ssl http2;
+	listen [::]:{{ 8443 if matrix_nginx_proxy_enabled else 443 }} ssl http2;
+
+	server_name {{ matrix_nginx_proxy_proxy_grafana_hostname }};
+
+	server_tokens off;
+	root /dev/null;
+
+	ssl_certificate {{ matrix_ssl_config_dir_path }}/live/{{ matrix_nginx_proxy_proxy_grafana_hostname }}/fullchain.pem;
+	ssl_certificate_key {{ matrix_ssl_config_dir_path }}/live/{{ matrix_nginx_proxy_proxy_grafana_hostname }}/privkey.pem;
+
+	ssl_protocols {{ matrix_nginx_proxy_ssl_protocols }};
+	{% if matrix_nginx_proxy_ssl_ciphers != "" %}
+	ssl_ciphers {{ matrix_nginx_proxy_ssl_ciphers }};
+	{% endif %}
+	ssl_prefer_server_ciphers {{ matrix_nginx_proxy_ssl_prefer_server_ciphers }};
+
+	{{ render_vhost_directives() }}
+}
+{% endif %}
--- a/roles/matrix-prometheus-node-exporter/defaults/main.yml
+++ b/roles/matrix-prometheus-node-exporter/defaults/main.yml
@ -0,0 +1,21 @@
+# matrix-prometheus-node-exporter is an Prometheus exporter for machine metrics
+# See: https://prometheus.io/docs/guides/node-exporter/
+
+matrix_prometheus_node_exporter_enabled: false
+
+matrix_prometheus_node_exporter_docker_image: "docker.io/prom/node-exporter:v1.1.0"
+matrix_prometheus_node_exporter_docker_image_force_pull: "{{ matrix_prometheus_node_exporter_docker_image.endswith(':latest') }}"
+
+# A list of extra arguments to pass to the container
+matrix_prometheus_node_exporter_container_extra_arguments: []
+
+# List of systemd services that matrix-prometheus.service depends on
+matrix_prometheus_node_exporter_systemd_required_services_list: ['docker.service']
+
+# List of systemd services that matrix-prometheus.service wants
+matrix_prometheus_node_exporter_systemd_wanted_services_list: []
+
+# Controls whether the matrix-prometheus container exposes its HTTP port (tcp/9100 in the container).
+#
+# Takes an "<ip>:<port>" or "<port>" value (e.g. "127.0.0.1:9100"), or empty string to not expose.
+matrix_prometheus_node_exporter_container_http_host_bind_port: ''
--- a/roles/matrix-prometheus-node-exporter/tasks/init.yml
+++ b/roles/matrix-prometheus-node-exporter/tasks/init.yml
@ -0,0 +1,5 @@
+- set_fact:
+    matrix_systemd_services_list: "{{ matrix_systemd_services_list + ['matrix-prometheus-node-exporter.service'] }}"
+  when: matrix_prometheus_node_exporter_enabled|bool
+
+
--- a/roles/matrix-prometheus-node-exporter/tasks/main.yml
+++ b/roles/matrix-prometheus-node-exporter/tasks/main.yml
@ -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-node-exporter
--- a/roles/matrix-prometheus-node-exporter/tasks/setup.yml
+++ b/roles/matrix-prometheus-node-exporter/tasks/setup.yml
@ -0,0 +1,60 @@
+---
+
+#
+# Tasks related to setting up matrix-prometheus-node-exporter
+#
+
+- name: Ensure matrix-prometheus-node-exporter image is pulled
+  docker_image:
+    name: "{{ matrix_prometheus_node_exporter_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_prometheus_node_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_node_exporter_docker_image_force_pull }}"
+  when: "matrix_prometheus_node_exporter_enabled|bool"
+
+- name: Ensure matrix-prometheus-node-exporter.service installed
+  template:
+    src: "{{ role_path }}/templates/systemd/matrix-prometheus-node-exporter.service.j2"
+    dest: "{{ matrix_systemd_path }}/matrix-prometheus-node-exporter.service"
+    mode: 0644
+  register: matrix_prometheus_node_exporter_systemd_service_result
+  when: matrix_prometheus_node_exporter_enabled|bool
+
+- name: Ensure systemd reloaded after matrix-prometheus.service installation
+  service:
+    daemon_reload: yes
+  when: "matrix_prometheus_node_exporter_enabled|bool and matrix_prometheus_node_exporter_systemd_service_result.changed"
+
+#
+# Tasks related to getting rid of matrix-prometheus-node-exporter (if it was previously enabled)
+#
+
+- name: Check existence of matrix-prometheus-node-exporter service
+  stat:
+    path: "{{ matrix_systemd_path }}/matrix-prometheus-node-exporter.service"
+  register: matrix_prometheus_node_exporter_service_stat
+
+- name: Ensure matrix-prometheus-node-exporter is stopped
+  service:
+    name: matrix-prometheus-node-exporter
+    state: stopped
+    daemon_reload: yes
+  register: stopping_result
+  when: "not matrix_prometheus_node_exporter_enabled|bool and matrix_prometheus_node_exporter_service_stat.stat.exists"
+
+- name: Ensure matrix-prometheus-node-exporter.service doesn't exist
+  file:
+    path: "{{ matrix_systemd_path }}/matrix-prometheus-node-exporter.service"
+    state: absent
+  when: "not matrix_prometheus_node_exporter_enabled|bool and matrix_prometheus_node_exporter_service_stat.stat.exists"
+
+- name: Ensure systemd reloaded after matrix-prometheus-node-exporter.service removal
+  service:
+    daemon_reload: yes
+  when: "not matrix_prometheus_node_exporter_enabled|bool and matrix_prometheus_node_exporter_service_stat.stat.exists"
+
+- name: Ensure matrix-prometheus-node-exporter Docker image doesn't exist
+  docker_image:
+    name: "{{ matrix_prometheus_node_exporter_docker_image }}"
+    state: absent
+  when: "not matrix_prometheus_node_exporter_enabled|bool"
--- a/roles/matrix-prometheus-node-exporter/tasks/validate_config.yml
+++ b/roles/matrix-prometheus-node-exporter/tasks/validate_config.yml
@ -0,0 +1,7 @@
+---
+
+- name: Fail if Synapse metrics or Prometheus Node Exporter not enabled
+  fail:
+    msg: >
+      You need to enable `matrix_synapse_metrics_enabled` and/or `matrix_prometheus_node_exporter_enabled` for Prometheus grab metrics.
+  when: "not matrix_synapse_metrics_enabled and not matrix_prometheus_node_exporter_enabled"
--- a/roles/matrix-prometheus-node-exporter/templates/systemd/matrix-prometheus-node-exporter.service.j2
+++ b/roles/matrix-prometheus-node-exporter/templates/systemd/matrix-prometheus-node-exporter.service.j2
@ -0,0 +1,44 @@
+#jinja2: lstrip_blocks: "True"
+[Unit]
+Description=matrix-prometheus-node-exporter
+{% for service in matrix_prometheus_node_exporter_systemd_required_services_list %}
+Requires={{ service }}
+After={{ service }}
+{% endfor %}
+{% for service in matrix_prometheus_node_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-node-exporter 2>/dev/null'
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-prometheus-node-exporter 2>/dev/null'
+
+
+ExecStart={{ matrix_host_command_docker }} run --rm --name matrix-prometheus-node-exporter \
+			--log-driver=none \
+			--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
+			--cap-drop=ALL \
+			--read-only \
+			{% if matrix_prometheus_node_exporter_container_http_host_bind_port %}
+			-p {{ matrix_prometheus_node_exporter_container_http_host_bind_port }}:9100 \
+			{% endif %}
+			{% for arg in matrix_prometheus_node_exporter_container_extra_arguments %}
+			{{ arg }} \
+			{% endfor %}
+			--net=host \
+			--pid=host \
+			--mount type=bind,src=/,dst=/host,ro,bind-propagation=rslave \
+			{{ matrix_prometheus_node_exporter_docker_image }} \
+			--path.rootfs=/host
+
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-prometheus-node-exporter 2>/dev/null'
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-prometheus-node-exporter 2>/dev/null'
+Restart=always
+RestartSec=30
+SyslogIdentifier=matrix-prometheus-node-exporter
+
+[Install]
+WantedBy=multi-user.target
--- a/roles/matrix-prometheus/defaults/main.yml
+++ b/roles/matrix-prometheus/defaults/main.yml
@ -0,0 +1,66 @@
+# matrix-prometheus is an open-source systems monitoring and alerting toolkit
+# See: https://github.com/matrix-org/synapse/blob/master/docs/metrics-howto.md
+
+matrix_prometheus_enabled: false
+
+matrix_prometheus_docker_image: "docker.io/prom/prometheus:v2.24.1"
+matrix_prometheus_docker_image_force_pull: "{{ matrix_prometheus_docker_image.endswith(':latest') }}"
+
+matrix_prometheus_base_path: "{{ matrix_base_data_path }}/prometheus"
+matrix_prometheus_config_path: "{{ matrix_prometheus_base_path }}/config"
+matrix_prometheus_data_path: "{{ matrix_prometheus_base_path }}/data"
+
+# A list of extra arguments to pass to the container
+matrix_prometheus_container_extra_arguments: []
+
+# List of systemd services that matrix-prometheus.service depends on
+matrix_prometheus_systemd_required_services_list: ['docker.service']
+
+# List of systemd services that matrix-prometheus.service wants
+matrix_prometheus_systemd_wanted_services_list: []
+
+# Controls whether the matrix-prometheus container exposes its HTTP port (tcp/9090 in the container).
+#
+# Takes an "<ip>:<port>" or "<port>" value (e.g. "127.0.0.1:9090"), or empty string to not expose.
+matrix_prometheus_container_http_host_bind_port: ''
+
+# Tells whether the "synapse" scraper configuration is enabled.
+matrix_prometheus_scraper_synapse_enabled: false
+
+# Tells whether to download and load a Synapse rules file
+matrix_prometheus_scraper_synapse_rules_enabled: "{{ matrix_prometheus_scraper_synapse_enabled }}"
+matrix_prometheus_scraper_synapse_rules_synapse_tag: "master"
+matrix_prometheus_scraper_synapse_rules_download_url: "https://raw.githubusercontent.com/matrix-org/synapse/{{ matrix_prometheus_scraper_synapse_rules_synapse_tag }}/contrib/prometheus/synapse-v2.rules"
+
+matrix_prometheus_scraper_synapse_targets: []
+
+# Tells whether the "node" scraper configuration is enabled.
+# This configuration aims to scrape the current node (this server).
+matrix_prometheus_scraper_node_enabled: false
+
+# Target addresses for the "node" scraper configuration.
+# Unless you define this as a non-empty list, it gets populated at runtime with the IP address of `matrix-prometheus-node-exporter` and port 9100.
+matrix_prometheus_scraper_node_targets: []
+
+# Default prometheus configuration template which covers the generic use case.
+# You can customize it by controlling the various variables inside it.
+#
+# For a more advanced customization, you can extend the default (see `matrix_prometheus_configuration_extension_yaml`)
+# or completely replace this variable with your own template.
+matrix_prometheus_configuration_yaml: "{{ lookup('template', 'templates/prometheus.yml.j2') }}"
+
+matrix_prometheus_configuration_extension_yaml: |
+  # Your custom YAML configuration goes here.
+  # This configuration extends the default starting configuration (`matrix_prometheus_configuration_yaml`).
+  #
+  # You can override individual variables from the default configuration, or introduce new ones.
+  #
+  # If you need something more special, you can take full control by
+  # completely redefining `matrix_prometheus_configuration_yaml`.
+
+matrix_prometheus_configuration_extension: "{{ matrix_prometheus_configuration_extension_yaml|from_yaml if matrix_prometheus_configuration_extension_yaml|from_yaml is mapping else {} }}"
+
+# Holds the final configuration (a combination of the default and its extension).
+# You most likely don't need to touch this variable. Instead, see `matrix_prometheus_configuration_yaml`.
+matrix_prometheus_configuration: "{{ matrix_prometheus_configuration_yaml|from_yaml|combine(matrix_prometheus_configuration_extension, recursive=True) }}"
+
--- a/roles/matrix-prometheus/tasks/init.yml
+++ b/roles/matrix-prometheus/tasks/init.yml
@ -0,0 +1,5 @@
+- set_fact:
+    matrix_systemd_services_list: "{{ matrix_systemd_services_list + ['matrix-prometheus.service'] }}"
+  when: matrix_prometheus_enabled|bool
+
+
--- a/roles/matrix-prometheus/tasks/main.yml
+++ b/roles/matrix-prometheus/tasks/main.yml
@ -0,0 +1,21 @@
+- import_tasks: "{{ role_path }}/tasks/init.yml"
+  tags:
+    - always
+
+- import_tasks: "{{ role_path }}/tasks/validate_config.yml"
+  when: run_setup|bool
+  tags:
+    - setup-all
+    - setup-prometheus
+
+- import_tasks: "{{ role_path }}/tasks/setup_install.yml"
+  when: "run_setup|bool and matrix_prometheus_enabled|bool"
+  tags:
+    - setup-all
+    - setup-prometheus
+
+- import_tasks: "{{ role_path }}/tasks/setup_uninstall.yml"
+  when: "run_setup|bool and not matrix_prometheus_enabled|bool"
+  tags:
+    - setup-all
+    - setup-prometheus
--- a/roles/matrix-prometheus/tasks/setup_install.yml
+++ b/roles/matrix-prometheus/tasks/setup_install.yml
@ -0,0 +1,66 @@
+---
+
+- name: Ensure matrix-prometheus image is pulled
+  docker_image:
+    name: "{{ matrix_prometheus_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_prometheus_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_docker_image_force_pull }}"
+
+- name: Ensure Prometheus paths exists
+  file:
+    path: "{{ item }}"
+    state: directory
+    mode: 0750
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  with_items:
+    - "{{ matrix_prometheus_base_path }}"
+    - "{{ matrix_prometheus_config_path }}"
+    - "{{ matrix_prometheus_data_path }}"
+
+- block:
+    # Well, this actually creates the network if it doesn't exist, but..
+    # The network should have been created by `matrix-base` already.
+    # We don't rely on that other call and its result, because it runs
+    # on `--tags=setup-all`, but will get skipped during `--tags=setup-prometheus`.
+    - name: Fetch Matrix Docker network details
+      docker_network:
+        name: "{{ matrix_docker_network }}"
+        driver: bridge
+      register: matrix_docker_network_info
+
+    - set_fact:
+        matrix_prometheus_scraper_node_targets: ["{{ matrix_docker_network_info.network.IPAM.Config[0].Gateway }}:9100"]
+  when: "matrix_prometheus_scraper_node_enabled|bool and matrix_prometheus_scraper_node_targets|length == 0"
+
+
+- name: Download synapse-v2.rules
+  get_url:
+    url: "{{ matrix_prometheus_scraper_synapse_rules_download_url }}"
+    dest: "{{ matrix_prometheus_config_path }}/synapse-v2.rules"
+    force: true
+    mode: 0440
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  when: "matrix_prometheus_scraper_synapse_rules_enabled|bool"
+
+- name: Ensure prometheus.yml installed
+  copy:
+    content: "{{ matrix_prometheus_configuration|to_nice_yaml }}"
+    dest: "{{ matrix_prometheus_config_path }}/prometheus.yml"
+    mode: 0644
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+
+- name: Ensure matrix-prometheus.service installed
+  template:
+    src: "{{ role_path }}/templates/systemd/matrix-prometheus.service.j2"
+    dest: "{{ matrix_systemd_path }}/matrix-prometheus.service"
+    mode: 0644
+  register: matrix_prometheus_systemd_service_result
+
+- name: Ensure systemd reloaded after matrix-prometheus.service installation
+  service:
+    daemon_reload: yes
+  when: "matrix_prometheus_systemd_service_result.changed|bool"
--- a/roles/matrix-prometheus/tasks/setup_uninstall.yml
+++ b/roles/matrix-prometheus/tasks/setup_uninstall.yml
@ -0,0 +1,31 @@
+---
+
+- name: Check existence of matrix-prometheus service
+  stat:
+    path: "{{ matrix_systemd_path }}/matrix-prometheus.service"
+  register: matrix_prometheus_service_stat
+
+- name: Ensure matrix-prometheus is stopped
+  service:
+    name: matrix-prometheus
+    state: stopped
+    daemon_reload: yes
+  register: stopping_result
+  when: "matrix_prometheus_service_stat.stat.exists|bool"
+
+- name: Ensure matrix-prometheus.service doesn't exist
+  file:
+    path: "{{ matrix_systemd_path }}/matrix-prometheus.service"
+    state: absent
+  when: "matrix_prometheus_service_stat.stat.exists|bool"
+
+- name: Ensure systemd reloaded after matrix-prometheus.service removal
+  service:
+    daemon_reload: yes
+  when: "matrix_prometheus_service_stat.stat.exists|bool"
+
+- name: Ensure matrix-prometheus Docker image doesn't exist
+  docker_image:
+    name: "{{ matrix_prometheus_docker_image }}"
+    state: absent
+  when: "not matrix_prometheus_enabled|bool"
--- a/roles/matrix-prometheus/tasks/validate_config.yml
+++ b/roles/matrix-prometheus/tasks/validate_config.yml
@ -0,0 +1,7 @@
+---
+
+- name: Fail if Synapse metrics or Prometheus Node Exporter not enabled
+  fail:
+    msg: >
+      You need to enable `matrix_prometheus_scraper_synapse_enabled` and/or `matrix_prometheus_scraper_node_enabled` for Prometheus grab metrics.
+  when: "not matrix_prometheus_scraper_synapse_enabled and not matrix_prometheus_scraper_node_enabled"
--- a/roles/matrix-prometheus/templates/prometheus.yml.j2
+++ b/roles/matrix-prometheus/templates/prometheus.yml.j2
@ -0,0 +1,40 @@
+#jinja2: lstrip_blocks: "True"
+global:
+  scrape_interval:     15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
+  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.
+  # scrape_timeout is set to the global default (10s).
+
+# Load rules once and periodically evaluate them according to the global 'evaluation_interval'.
+rule_files:
+    {% if matrix_prometheus_scraper_synapse_rules_enabled %}
+    - 'synapse-v2.rules'
+    {% endif %}
+
+# A scrape configuration containing exactly one endpoint to scrape:
+# Here it's Prometheus itself.
+scrape_configs:
+  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
+  - job_name: 'prometheus'
+
+    # Override the global default and scrape targets from this job every 5 seconds.
+    scrape_interval: 5s
+    scrape_timeout: 5s
+
+    # metrics_path defaults to '/metrics'
+    # scheme defaults to 'http'.
+
+    static_configs:
+      - targets: ['localhost:9090']
+
+  {% if matrix_prometheus_scraper_synapse_enabled %}
+  - job_name: 'synapse'
+    metrics_path: '/_synapse/metrics'
+    static_configs:
+    - targets: {{ matrix_prometheus_scraper_synapse_targets|to_json }}
+  {% endif %}
+
+  {% if matrix_prometheus_scraper_node_enabled %}
+  - job_name: node
+    static_configs:
+      - targets: {{ matrix_prometheus_scraper_node_targets|to_json }}
+  {% endif %}
--- a/roles/matrix-prometheus/templates/systemd/matrix-prometheus.service.j2
+++ b/roles/matrix-prometheus/templates/systemd/matrix-prometheus.service.j2
@ -0,0 +1,43 @@
+#jinja2: lstrip_blocks: "True"
+[Unit]
+Description=matrix-prometheus
+{% for service in matrix_prometheus_systemd_required_services_list %}
+Requires={{ service }}
+After={{ service }}
+{% endfor %}
+{% for service in matrix_prometheus_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 2>/dev/null'
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-prometheus 2>/dev/null'
+
+
+ExecStart={{ matrix_host_command_docker }} run --rm --name matrix-prometheus \
+			--log-driver=none \
+			--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
+			--cap-drop=ALL \
+			--read-only \
+			--network={{ matrix_docker_network }} \
+			{% if matrix_prometheus_container_http_host_bind_port %}
+			-p {{ matrix_prometheus_container_http_host_bind_port }}:9090 \
+			{% endif %}
+			-v {{ matrix_prometheus_config_path }}:/etc/prometheus:z \
+			-v {{ matrix_prometheus_data_path }}:/prometheus:z \
+			{% for arg in matrix_prometheus_container_extra_arguments %}
+			{{ arg }} \
+			{% endfor %}
+			{{ matrix_prometheus_docker_image }}
+
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-prometheus 2>/dev/null'
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-prometheus 2>/dev/null'
+Restart=always
+RestartSec=30
+SyslogIdentifier=matrix-prometheus
+
+[Install]
+WantedBy=multi-user.target
--- a/setup.yml
+++ b/setup.yml
@ -28,6 +28,9 @@
    - matrix-bot-matrix-reminder-bot
    - matrix-synapse
    - matrix-synapse-admin
+    - matrix-prometheus-node-exporter
+    - matrix-prometheus
+    - matrix-grafana
    - matrix-registration
    - matrix-client-element
    - matrix-jitsi