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-bridge-appservice-slack/tasks/migrate_nedb_to_postgres.yml

@@ -0,0 +1,72 @@
+---
+
+- name: Fail if Postgres not enabled
+  ansible.builtin.fail:
+    msg: "Postgres via the matrix-postgres role is not enabled (`matrix_postgres_enabled`). Cannot migrate."
+  when: "not matrix_postgres_enabled | bool"
+
+# Defaults
+
+- name: Set postgres_start_wait_time, if not provided
+  ansible.builtin.set_fact:
+    postgres_start_wait_time: 15
+  when: "postgres_start_wait_time | default('') == ''"
+
+# Actual import work
+
+- name: Ensure matrix-postgres is started
+  ansible.builtin.service:
+    name: matrix-postgres
+    state: started
+    daemon_reload: true
+  register: matrix_postgres_service_start_result
+
+- name: Wait a bit, so that Postgres can start
+  ansible.builtin.wait_for:
+    timeout: "{{ postgres_start_wait_time }}"
+  delegate_to: 127.0.0.1
+  become: false
+  when: "matrix_postgres_service_start_result.changed | bool"
+
+- name: Ensure matrix-appservice-slack is stopped
+  ansible.builtin.service:
+    name: matrix-appservice-slack
+    state: stopped
+
+- name: Import appservice-slack NeDB database into Postgres
+  ansible.builtin.command:
+    cmd: >-
+      {{ matrix_host_command_docker }} run
+      --rm
+      --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
+      --cap-drop=ALL
+      --network={{ matrix_docker_network }}
+      --mount type=bind,src={{ matrix_appservice_slack_data_path }},dst=/data
+      --entrypoint=/bin/sh
+      {{ matrix_appservice_slack_docker_image }}
+      -c
+      '/usr/local/bin/node /usr/src/app/lib/scripts/migrateToPostgres.js --dbdir /data --connectionString {{ matrix_appservice_slack_database_connection_string }}'
+  register: matrix_appservice_slack_import_nedb_to_postgres_result
+  changed_when: matrix_appservice_slack_import_nedb_to_postgres_result.rc == 0
+
+- name: Archive NeDB database files
+  ansible.builtin.command:
+    cmd: "mv {{ matrix_appservice_slack_data_path }}/{{ item }} {{ matrix_appservice_slack_data_path }}/{{ item }}.backup"
+  register: matrix_appservice_slack_import_nedb_to_postgres_move_result
+  changed_when: matrix_appservice_slack_import_nedb_to_postgres_move_result.rc == 0
+  with_items:
+    - teams.db
+    - room-store.db
+    - user-store.db
+    - event-store.db
+
+- name: Inject result
+  ansible.builtin.set_fact:
+    matrix_playbook_runtime_results: |
+      {{
+        matrix_playbook_runtime_results | default([])
+        +
+        [
+          "NOTE: Your appservice-slack database files have been imported into Postgres. The original database files have been moved from `{{ matrix_appservice_slack_data_path }}/*.db` to `{{ matrix_appservice_slack_data_path }}/*.db.backup`. When you've confirmed that the import went well and everything works, you should be able to safely delete these files."
+        ]
+      }}