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-postgres-backup/tasks/init.yml

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

roles/custom/matrix-postgres-backup/tasks/main.yml

@@ -0,0 +1,17 @@
+---
+
+- 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_postgres_backup_enabled | bool"
+  tags:
+    - setup-all
+    - setup-postgres-backup
+
+- ansible.builtin.import_tasks: "{{ role_path }}/tasks/setup_postgres_backup.yml"
+  when: run_setup | bool
+  tags:
+    - setup-all
+    - setup-postgres-backup

roles/custom/matrix-postgres-backup/tasks/setup_postgres_backup.yml

@@ -0,0 +1,112 @@
+---
+
+#
+# Tasks related to setting up postgres backup
+#
+- ansible.builtin.import_role:
+    name: custom/matrix-postgres
+    tasks_from: detect_existing_postgres_version
+  when: 'matrix_postgres_backup_enabled | bool and matrix_postgres_backup_postgres_data_path != ""'
+
+# If we have found an existing version (installed from before), we use its corresponding Docker image.
+# If not, we install using the latest Postgres.
+#
+# Upgrading is supposed to be performed separately and explicitly (see `upgrade_postgres.yml`).
+- ansible.builtin.set_fact:
+    matrix_postgres_backup_docker_image_to_use: "{{ matrix_postgres_backup_docker_image_latest if matrix_postgres_backup_detected_version_corresponding_docker_image | default('') == '' else matrix_postgres_backup_detected_version_corresponding_docker_image }}"
+  when: matrix_postgres_backup_enabled | bool
+
+- name: Ensure postgres backup Docker image is pulled
+  community.docker.docker_image:
+    name: "{{ matrix_postgres_backup_docker_image_to_use }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_postgres_backup_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_postgres_backup_docker_image_force_pull }}"
+  when: matrix_postgres_backup_enabled | bool
+  register: result
+  retries: "{{ matrix_container_retries_count }}"
+  delay: "{{ matrix_container_retries_delay }}"
+  until: result is not failed
+
+- name: Ensure Postgres backup paths exist
+  ansible.builtin.file:
+    path: "{{ item }}"
+    state: directory
+    mode: 0700
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  with_items:
+    - "{{ matrix_postgres_backup_path }}"
+  when: matrix_postgres_backup_enabled | bool
+
+- name: Ensure Postgres environment variables file created
+  ansible.builtin.template:
+    src: "{{ role_path }}/templates/{{ item }}.j2"
+    dest: "{{ matrix_postgres_backup_path }}/{{ item }}"
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+    mode: 0640
+  with_items:
+    - "env-postgres-backup"
+  when: matrix_postgres_backup_enabled | bool
+
+- name: Ensure matrix-postgres-backup.service installed
+  ansible.builtin.template:
+    src: "{{ role_path }}/templates/systemd/matrix-postgres-backup.service.j2"
+    dest: "{{ matrix_systemd_path }}/matrix-postgres-backup.service"
+    mode: 0644
+  register: matrix_postgres_backup_systemd_service_result
+  when: matrix_postgres_backup_enabled | bool
+
+- name: Ensure systemd reloaded after matrix-postgres-backup.service installation
+  ansible.builtin.service:
+    daemon_reload: true
+  when: "matrix_postgres_backup_enabled | bool and matrix_postgres_backup_systemd_service_result.changed"
+
+#
+# Tasks related to getting rid of postgres backup (if it was previously enabled)
+#
+
+- name: Check existence of matrix-postgres-backup service
+  ansible.builtin.stat:
+    path: "{{ matrix_systemd_path }}/matrix-postgres-backup.service"
+  register: matrix_postgres_backup_service_stat
+  when: "not matrix_postgres_backup_enabled | bool"
+
+- name: Ensure matrix-postgres-backup is stopped
+  ansible.builtin.service:
+    name: matrix-postgres-backup
+    state: stopped
+    enabled: false
+    daemon_reload: true
+  when: "not matrix_postgres_backup_enabled | bool and matrix_postgres_backup_service_stat.stat.exists"
+
+- name: Ensure matrix-postgres-backup.service doesn't exist
+  ansible.builtin.file:
+    path: "{{ matrix_systemd_path }}/matrix-postgres-backup.service"
+    state: absent
+  when: "not matrix_postgres_backup_enabled | bool and matrix_postgres_backup_service_stat.stat.exists"
+
+- name: Ensure systemd reloaded after matrix-postgres-backup.service removal
+  ansible.builtin.service:
+    daemon_reload: true
+  when: "not matrix_postgres_backup_enabled | bool and matrix_postgres_backup_service_stat.stat.exists"
+
+- name: Check existence of matrix-postgres-backup backup path
+  ansible.builtin.stat:
+    path: "{{ matrix_postgres_backup_path }}"
+  register: matrix_postgres_backup_path_stat
+  when: "not matrix_postgres_backup_enabled | bool"
+
+# We just want to notify the user. Deleting data is too destructive.
+- name: Inject warning if matrix-postgres backup data remains
+  ansible.builtin.set_fact:
+    matrix_playbook_runtime_results: |
+      {{
+        matrix_playbook_runtime_results | default([])
+        +
+        [
+          "NOTE: You are not using the local backup service to backup the PostgreSQL database, but some old data remains from before in `{{ matrix_postgres_backup_path }}`. Feel free to delete it."
+        ]
+      }}
+  when: "not matrix_postgres_backup_enabled | bool and matrix_postgres_backup_path_stat.stat.exists"

roles/custom/matrix-postgres-backup/tasks/validate_config.yml

@@ -0,0 +1,27 @@
+---
+
+- name: Fail if required Postgres settings not defined
+  ansible.builtin.fail:
+    msg: >-
+      You need to define a required configuration setting (`{{ item }}`).
+  when: "vars[item] == ''"
+  with_items:
+    - "matrix_postgres_backup_connection_hostname"
+    - "matrix_postgres_backup_connection_username"
+    - "matrix_postgres_backup_connection_password"
+    - "matrix_postgres_backup_connection_port"
+    - "matrix_postgres_backup_schedule"
+    - "matrix_postgres_backup_keep_days"
+    - "matrix_postgres_backup_keep_weeks"
+    - "matrix_postgres_backup_keep_months"
+    - "matrix_postgres_backup_path"
+    - "matrix_postgres_backup_databases"
+
+- name: (Deprecation) Catch and report renamed settings
+  ansible.builtin.fail:
+    msg: >-
+      Your configuration contains a variable, which now has a different name.
+      Please change your configuration to rename the variable (`{{ item.old }}` -> `{{ item.new }}`).
+  when: "item.old in vars"
+  with_items:
+    - {'old': 'matrix_postgres_backup_docker_image_suffix', 'new': 'matrix_postgres_backup_docker_image_distro'}