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/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