expose prometheus process args

roles/matrix-prometheus/defaults/main.yml

@@ -26,6 +26,13 @@ matrix_prometheus_systemd_wanted_services_list: []
 # 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 extra arguments to pass to the prometheus process
+matrix_prometheus_process_extra_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"
+
 # Tells whether the "synapse" scraper configuration is enabled.
 matrix_prometheus_scraper_synapse_enabled: false
 

roles/matrix-prometheus/templates/systemd/matrix-prometheus.service.j2

@@ -31,7 +31,8 @@ ExecStart={{ matrix_host_command_docker }} run --rm --name matrix-prometheus \
 			{% for arg in matrix_prometheus_container_extra_arguments %}
 			{{ arg }} \
 			{% endfor %}
-			{{ matrix_prometheus_docker_image }}
+			{{ matrix_prometheus_docker_image }} \
+			{{ matrix_prometheus_process_extra_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'