container, service: Support reloading containers on template file change

roles/container/defaults/main.yaml

@@ -14,3 +14,4 @@ container_auto_update: true
 container_requires: []
 container_wants: []
 container_add_capabilities: []
+container_reload_method: none

roles/container/handlers/main.yaml

@@ -4,3 +4,9 @@
     systemd_restart_units: "{{ systemd_restart_units + [container_name ~ '.service'] }}" # noqa: var-naming[no-role-prefix]
   changed_when: true
   notify: Apply systemd unit restarts
+
+- name: Reload container service {{ container_name }}
+  ansible.builtin.systemd_service:
+    name: "{{ container_name }}.service"
+    state: reloaded
+  when: "container_name ~ '.service' not in systemd_restart_units"

roles/container/meta/argument_specs.yaml

@@ -212,3 +212,21 @@ argument_specs:
         type: bool
         required: false
         default: true
+      container_reload_method:
+        description: |
+          How to reload configuration when systemctl reload is called
+          kill: Sends SIGHUP to the container
+          command: Runs the specified command inside the container
+        type: str
+        required: false
+        default: none
+        choices:
+          - kill
+          - command
+          - none
+      container_reload_command:
+        description: >-
+          Command to run inside container when systemctl reload is called.
+          Required if container_reload_method is command, ignored otherwise.
+        type: str
+        required: false

roles/container/vars/main/general.yaml

@@ -69,6 +69,10 @@ _container_labels: >-
     else {}
   }}
 
+_container_reload_commands:
+  kill: podman kill --signal HUP {{ container_name }}
+  command: podman exec {{ container_name }} {{ container_reload_command }}
+
 _container_quadlet_unit_options: |
   [Unit]
   Description=Container {{ container_name }}
@@ -90,8 +94,12 @@ _container_quadlet_auto_start_options: |
 
   [Install]
   WantedBy=multi-user.target
+_container_quadlet_reload_options: |
+  [Service]
+  ExecReload={{ _container_reload_commands[container_reload_method] }}
 _container_quadlet_options_incl_empty:
   - "{{ 'AutoUpdate=registry' if container_auto_update else '' }}"
   - "{{ _container_quadlet_unit_options }}"
   - "{{ _container_quadlet_auto_start_options if container_auto_start else '' }}"
+  - "{{ _container_quadlet_reload_options if container_reload_method != 'none' else '' }}"
 _container_quadlet_options: "{{ _container_quadlet_options_incl_empty | select('!=', '') }}"

roles/service/defaults/main.yaml

@@ -18,6 +18,8 @@ service_container_devices: []
 service_container_secrets: []
 service_container_env: {}
 service_container_add_capabilities: []
+service_container_reload_method: none
+service_container_reload_command: ""
 
 service_database_type: none
 service_database_additional_networks: []

roles/service/meta/argument_specs.yaml

@@ -298,6 +298,26 @@ argument_specs:
         default: []
         elements: str
 
+      service_container_reload_method:
+        description: |
+          How to reload configuration when systemctl reload is called
+          kill: Sends SIGHUP to the container
+          command: Runs the specified command inside the container
+        type: str
+        required: false
+        default: none
+        choices:
+          - kill
+          - command
+          - none
+      service_container_reload_command:
+        description: >-
+          Command to run inside container when systemctl reload is called.
+          Required if container_reload_method is command, ignored otherwise.
+        type: str
+        required: false
+        default: ""
+
       service_database_type:
         description:
           - Database type to set up.
@@ -553,6 +573,25 @@ argument_specs:
             type: list
             required: false
             elements: str
+          reload_method:
+            description: |
+              How to reload configuration when systemctl reload is called
+              kill: Sends SIGHUP to the container
+              command: Runs the specified command inside the container
+            type: str
+            required: false
+            default: none
+            choices:
+              - kill
+              - command
+              - none
+          reload_command:
+            description: >-
+              Command to run inside container when systemctl reload is called.
+              Required if container_reload_method is command, ignored otherwise.
+            type: str
+            required: false
+            default: ""
           secrets:
             description:
               - >

roles/service/tasks/additional.yaml

@@ -16,6 +16,8 @@
     container_secrets: "{{ _service_additional_container_secrets }}"
     container_env: "{{ _service_additional_container.env }}"
     container_add_capabilities: "{{ _service_additional_container.add_capabilities }}"
+    container_reload_method: "{{ _service_additional_container.reload_method }}"
+    container_reload_command: "{{ _service_additional_container.reload_command }}"
     container_requires: "{{ _service_additional_container_requires }}"
     container_wants: "{{ _service_additional_container_wants }}"
     container_auto_update: "{{ service_auto_update }}"

roles/service/tasks/host_mounts.yaml

@@ -24,7 +24,9 @@
     dest: "{{ item[1] }}"
     mode: "{{ item[0].mode | default('0644') }}"
     validate: "{{ validate if item[0].template_validate_command is defined else omit }}"
-  notify: Restart container service {{ service_name }}
+  notify: >-
+    {{ 'Reload' if service_container_reload_method != 'none' else 'Restart' }}
+    container service {{ service_name }}
   loop: "{{ _service_all_template_mounts | zip(_service_all_template_mount_host_files) }}"
   vars:
     validate: >-

roles/service/tasks/main.yaml

@@ -48,6 +48,8 @@
     container_secrets: "{{ _service_container_secrets }}"
     container_env: "{{ service_container_env }}"
     container_add_capabilities: "{{ service_container_add_capabilities }}"
+    container_reload_method: "{{ service_container_reload_method }}"
+    container_reload_command: "{{ service_container_reload_command }}"
     container_requires: "{{ _service_container_requires }}"
     container_wants: "{{ _service_container_wants }}"
     container_auto_update: "{{ service_auto_update }}"

roles/service/vars/main/additional.yaml

@@ -18,6 +18,8 @@ _service_additional_container_same_image_defaults:
   devices: "{{ service_container_devices }}"
   env: "{{ service_container_env }}"
   add_capabilities: "{{ service_container_add_capabilities }}"
+  reload_method: "{{ service_container_reload_method }}"
+  reload_command: "{{ service_container_reload_command }}"
 
 _service_additional_container_different_image_defaults:
   user: ""
@@ -28,6 +30,8 @@ _service_additional_container_different_image_defaults:
   publish_ports: []
   env: {}
   add_capabilities: []
+  reload_method: none
+  reload_command: ""
   secrets: []
 
 _service_additional_same_image_containers: >-