Move roles/matrix* to roles/custom/matrix*

This paves the way for installing other roles into `roles/galaxy` using `ansible-galaxy`,
similar to how it's done in:

- https://github.com/spantaleev/gitea-docker-ansible-deploy
- https://github.com/spantaleev/nextcloud-docker-ansible-deploy

In the near future, we'll be removing a lot of the shared role code from here
and using upstream roles for it. Some of the core `matrix-*` roles have
already been extracted out into other reusable roles:

- https://github.com/devture/com.devture.ansible.role.postgres
- https://github.com/devture/com.devture.ansible.role.systemd_docker_base
- https://github.com/devture/com.devture.ansible.role.timesync
- https://github.com/devture/com.devture.ansible.role.vars_preserver
- https://github.com/devture/com.devture.ansible.role.playbook_runtime_messages
- https://github.com/devture/com.devture.ansible.role.playbook_help

We just need to migrate to those.

roles/custom/matrix-prometheus/defaults/main.yml

@@ -0,0 +1,82 @@
+---
+# matrix-prometheus is an open-source systems monitoring and alerting toolkit
+# See: https://github.com/matrix-org/synapse/blob/master/docs/metrics-howto.md
+# Project source code URL: https://github.com/prometheus/prometheus
+
+matrix_prometheus_enabled: false
+
+matrix_prometheus_version: v2.39.1
+matrix_prometheus_docker_image: "{{ matrix_container_global_registry_prefix }}prom/prometheus:{{ matrix_prometheus_version }}"
+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: ''
+
+# A list of default arguments to pass to the prometheus process
+matrix_prometheus_process_default_arguments:
+  - "--config.file=/etc/prometheus/prometheus.yml"
+  - "--storage.tsdb.path=/prometheus"
+  - "--web.console.libraries=/usr/share/prometheus/console_libraries"
+  - "--web.console.templates=/usr/share/prometheus/consoles"
+
+# A list of extra arguments to pass to the prometheus process
+matrix_prometheus_process_extra_arguments: []
+
+# holds the final list of process arguments
+matrix_prometheus_process_arguments: "{{ matrix_prometheus_process_default_arguments + matrix_prometheus_process_extra_arguments }}"
+
+# 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: []
+matrix_prometheus_scraper_synapse_workers_enabled_list: []
+
+# 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) }}"

roles/custom/matrix-prometheus/tasks/init.yml

@@ -0,0 +1,5 @@
+---
+
+- ansible.builtin.set_fact:
+    matrix_systemd_services_list: "{{ matrix_systemd_services_list + ['matrix-prometheus.service'] }}"
+  when: matrix_prometheus_enabled | bool

roles/custom/matrix-prometheus/tasks/main.yml

@@ -0,0 +1,23 @@
+---
+
+- ansible.builtin.import_tasks: "{{ role_path }}/tasks/init.yml"
+  tags:
+    - always
+
+- ansible.builtin.import_tasks: "{{ role_path }}/tasks/validate_config.yml"
+  when: "run_setup | bool and matrix_prometheus_enabled | bool"
+  tags:
+    - setup-all
+    - setup-prometheus
+
+- ansible.builtin.import_tasks: "{{ role_path }}/tasks/setup_install.yml"
+  when: "run_setup | bool and matrix_prometheus_enabled | bool"
+  tags:
+    - setup-all
+    - setup-prometheus
+
+- ansible.builtin.import_tasks: "{{ role_path }}/tasks/setup_uninstall.yml"
+  when: "run_setup | bool and not matrix_prometheus_enabled | bool"
+  tags:
+    - setup-all
+    - setup-prometheus

roles/custom/matrix-prometheus/tasks/setup_install.yml

@@ -0,0 +1,58 @@
+---
+
+- name: Ensure matrix-prometheus image is pulled
+  community.docker.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 }}"
+  register: result
+  retries: "{{ matrix_container_retries_count }}"
+  delay: "{{ matrix_container_retries_delay }}"
+  until: result is not failed
+
+- name: Ensure Prometheus paths exists
+  ansible.builtin.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 }}"
+
+- name: Download synapse-v2.rules
+  ansible.builtin.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"
+  register: result
+  retries: "{{ matrix_geturl_retries_count }}"
+  delay: "{{ matrix_geturl_retries_delay }}"
+  until: result is not failed
+
+- name: Ensure prometheus.yml installed
+  ansible.builtin.copy:
+    content: "{{ matrix_prometheus_configuration | to_nice_yaml(indent=2, width=999999) }}"
+    dest: "{{ matrix_prometheus_config_path }}/prometheus.yml"
+    mode: 0644
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+
+- name: Ensure matrix-prometheus.service installed
+  ansible.builtin.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
+  ansible.builtin.service:
+    daemon_reload: true
+  when: "matrix_prometheus_systemd_service_result.changed | bool"

roles/custom/matrix-prometheus/tasks/setup_uninstall.yml

@@ -0,0 +1,26 @@
+---
+
+- name: Check existence of matrix-prometheus service
+  ansible.builtin.stat:
+    path: "{{ matrix_systemd_path }}/matrix-prometheus.service"
+  register: matrix_prometheus_service_stat
+
+- name: Ensure matrix-prometheus is stopped
+  ansible.builtin.service:
+    name: matrix-prometheus
+    state: stopped
+    enabled: false
+    daemon_reload: true
+  register: stopping_result
+  when: "matrix_prometheus_service_stat.stat.exists | bool"
+
+- name: Ensure matrix-prometheus.service doesn't exist
+  ansible.builtin.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
+  ansible.builtin.service:
+    daemon_reload: true
+  when: "matrix_prometheus_service_stat.stat.exists | bool"

roles/custom/matrix-prometheus/tasks/validate_config.yml

@@ -0,0 +1,7 @@
+---
+
+- name: Fail if Synapse metrics or Prometheus Node Exporter not enabled
+  ansible.builtin.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"

roles/custom/matrix-prometheus/templates/prometheus.yml.j2

@@ -0,0 +1,66 @@
+#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 }}
+      labels:
+        instance: {{ matrix_domain | to_json }}
+        job: master
+        index: 0
+  {% for worker in matrix_prometheus_scraper_synapse_workers_enabled_list %}
+  {% if worker.metrics_port != 0 %}
+    - targets: ['{{ worker.name }}:{{ worker.metrics_port }}']
+      labels:
+        instance: {{ matrix_domain | to_json }}
+        worker_id: {{ worker.id | to_json }}
+        job: {{ worker.type | to_json }}
+        app: {{ worker.app | to_json }}
+  {% endif %}
+  {% endfor %}
+  {% endif %}
+
+  {% if matrix_prometheus_scraper_node_enabled %}
+  - job_name: node
+    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 %}
+
+  {% if matrix_prometheus_scraper_hookshot_enabled %}
+  - job_name: hookshot
+    static_configs:
+      - targets: {{ matrix_prometheus_scraper_hookshot_targets|to_json }}
+  {% endif %}

roles/custom/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 || true'
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-prometheus 2>/dev/null || true'
+
+
+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 }} {{ matrix_prometheus_process_arguments|join(' ') }}
+
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-prometheus 2>/dev/null || true'
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-prometheus 2>/dev/null || true'
+Restart=always
+RestartSec=30
+SyslogIdentifier=matrix-prometheus
+
+[Install]
+WantedBy=multi-user.target