Add support for matrix_dimension_systemd_{required,wanted}_services_list

We were referencing them from `group_vars/matrix_servers` since
recently, but there were no such variables and they weren't being put to
use.

roles/matrix-dimension/defaults/main.yml

@@ -15,6 +15,12 @@ matrix_dimension_base_path: "{{ matrix_base_data_path }}/dimension"
 matrix_dimension_docker_image: "docker.io/turt2live/matrix-dimension:latest"
 matrix_dimension_docker_image_force_pull: "{{ matrix_dimension_docker_image.endswith(':latest') }}"
 
+# List of systemd services that matrix-dimension.service depends on.
+matrix_dimension_systemd_required_services_list: ['docker.service']
+
+# List of systemd services that matrix-dimension.service wants
+matrix_dimension_systemd_wanted_services_list: []
+
 # The user and group id correspond to the node user in the `turt2live/matrix-dimension` image.
 matrix_dimension_user_uid: '1000'
 matrix_dimension_user_gid: '1000'

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

@@ -1,8 +1,13 @@
 #jinja2: lstrip_blocks: "True"
 [Unit]
 Description=Matrix Dimension
-After=docker.service
-Requires=docker.service
+{% for service in matrix_dimension_systemd_required_services_list %}
+Requires={{ service }}
+After={{ service }}
+{% endfor %}
+{% for service in matrix_dimension_systemd_wanted_services_list %}
+Wants={{ service }}
+{% endfor %}
 DefaultDependencies=no
 
 [Service]