Merge remote-tracking branch 'origin/master' into synapse-workers

Sync with upstream

roles/matrix-postgres/defaults/main.yml

@@ -35,4 +35,49 @@ matrix_postgres_process_extra_arguments: []
 # Takes an "<ip>:<port>" or "<port>" value (e.g. "127.0.0.1:5432"), or empty string to not expose.
 matrix_postgres_container_postgres_bind_port: ""
 
-matrix_postgres_tool_synapse_janitor: "https://raw.githubusercontent.com/xwiki-labs/synapse_scripts/a9188ff175ae581610f92d58ea6eac9a114d854b/synapse_janitor.sql"
+# A list of additional (databases and their credentials) to create.
+#
+# Example:
+# matrix_postgres_additional_databases:
+#   - name: matrix_appservice_discord
+#     username: matrix_appservice_discord
+#     password: some_password
+#   - name: matrix_appservice_slack
+#     username: matrix_appservice_slack
+#     password: some_password
+matrix_postgres_additional_databases: []
+
+# A list of roles/users to avoid creating when importing (or upgrading) the database.
+# If a dump file contains the roles and they've also been created beforehand (see `matrix_postgres_additional_databases`),
+# importing would fail.
+# We either need to not create them or to ignore the `CREATE ROLE` statements in the dump.
+matrix_postgres_import_roles_to_ignore: [matrix_postgres_connection_username]
+
+matrix_postgres_import_roles_ignore_regex: "^CREATE ROLE ({{ matrix_postgres_import_roles_to_ignore|join('|') }});"
+
+# A list of databases to avoid creating when importing (or upgrading) the database.
+# If a dump file contains the databases and they've also been created beforehand (see `matrix_postgres_additional_databases`),
+# importing would fail.
+# We either need to not create them or to ignore the `CREATE DATABASE` statements in the dump.
+matrix_postgres_import_databases_to_ignore: [matrix_postgres_db_name]
+
+matrix_postgres_import_databases_ignore_regex: "^CREATE DATABASE ({{ matrix_postgres_import_databases_to_ignore|join('|') }})\\s"
+
+# The number of seconds to wait after starting `matrix-postgres.service`
+# and before trying to run queries for creating additional databases/users against it.
+#
+# For most (subsequent) runs, Postgres would already be running, so no waiting will be happening at all.
+matrix_postgres_additional_databases_postgres_start_wait_timeout_seconds: 15
+
+
+matrix_postgres_pgloader_container_image_self_build: false
+matrix_postgres_pgloader_container_image_self_build_repo: "https://github.com/illagrenan/pgloader-docker.git"
+matrix_postgres_pgloader_container_image_self_build_repo_branch: "v{{ matrix_postgres_pgloader_docker_image_tag }}"
+matrix_postgres_pgloader_container_image_self_build_src_path: "{{ matrix_postgres_base_path }}/pgloader-container-src"
+
+# We use illagrenan/pgloader, instead of the more official dimitri/pgloader image,
+# because the official one only provides a `latest` tag.
+matrix_postgres_pgloader_docker_image: "{{ matrix_postgres_pgloader_docker_image_name_prefix }}illagrenan/pgloader:{{ matrix_postgres_pgloader_docker_image_tag }}"
+matrix_postgres_pgloader_docker_image_name_prefix: "{{ 'localhost/' if matrix_postgres_pgloader_container_image_self_build else 'docker.io/' }}"
+matrix_postgres_pgloader_docker_image_tag: "3.6.2"
+matrix_postgres_pgloader_docker_image_force_pull: "{{ matrix_postgres_pgloader_docker_image.endswith(':latest') }}"

roles/matrix-postgres/tasks/import_generic_sqlite_db.yml

@@ -0,0 +1,97 @@
+---
+
+# Pre-checks
+
+- name: Fail if Postgres not enabled
+  fail:
+    msg: "Postgres via the matrix-postgres role is not enabled (`matrix_postgres_enabled`). Cannot import."
+  when: "not matrix_postgres_enabled|bool"
+
+- name: Fail if playbook called incorrectly
+  fail:
+    msg: "The `sqlite_database_path` variable needs to be provided to this playbook, via --extra-vars"
+  when: "sqlite_database_path is not defined or sqlite_database_path.startswith('<')"
+
+- name: Check if the provided SQLite database file exists
+  stat:
+    path: "{{ sqlite_database_path }}"
+  register: sqlite_database_path_stat_result
+
+- name: Fail if provided SQLite database file doesn't exist
+  fail:
+    msg: "File cannot be found on the server at {{ sqlite_database_path }}"
+  when: "not sqlite_database_path_stat_result.stat.exists"
+
+# We either expect `postgres_db_connection_string` specifying a full Postgres database connection string,
+# or `postgres_connection_string_variable_name`, specifying a name of a variable, which contains a valid connection string.
+
+- block:
+    - name: Fail if postgres_connection_string_variable_name points to an undefined variable
+      fail: msg="postgres_connection_string_variable_name is defined, but there is no variable with the name `{{ postgres_connection_string_variable_name }}`"
+      when: "postgres_connection_string_variable_name not in vars"
+
+    - name: Get Postgres connection string from variable
+      set_fact:
+        postgres_db_connection_string: "{{ lookup('vars', postgres_connection_string_variable_name) }}"
+  when: 'postgres_connection_string_variable_name is defined'
+
+- name: Fail if playbook called incorrectly
+  fail:
+    msg: >-
+      Either a `postgres_db_connection_string` variable or a `postgres_connection_string_variable_name` needs to be provided to this playbook, via `--extra-vars`.
+      Example: `--extra-vars="postgres_db_connection_string=postgresql://username:password@localhost:<port>/database_name"` or `--extra-vars="postgres_connection_string_variable_name=matrix_appservice_discord_database_connString"`
+  when: "postgres_db_connection_string is not defined or not postgres_db_connection_string.startswith('postgresql://')"
+
+
+# Defaults
+
+- name: Set postgres_start_wait_time, if not provided
+  set_fact:
+    postgres_start_wait_time: 15
+  when: "postgres_start_wait_time|default('') == ''"
+
+
+# Actual import work
+
+- name: Ensure matrix-postgres is started
+  service:
+    name: matrix-postgres
+    state: started
+    daemon_reload: yes
+  register: matrix_postgres_service_start_result
+
+- name: Wait a bit, so that Postgres can start
+  wait_for:
+    timeout: "{{ postgres_start_wait_time }}"
+  delegate_to: 127.0.0.1
+  become: false
+  when: "matrix_postgres_service_start_result.changed|bool"
+
+- name: Import SQLite database from {{ sqlite_database_path }} into Postgres
+  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={{ sqlite_database_path }},dst=/in.db,ro
+      --entrypoint=/bin/sh
+      {{ matrix_postgres_pgloader_docker_image }}
+      -c
+      'pgloader /in.db {{ postgres_db_connection_string }}'
+
+- name: Archive SQLite database ({{ sqlite_database_path }} -> {{ sqlite_database_path }}.backup)
+  command:
+    cmd: "mv {{ sqlite_database_path }} {{ sqlite_database_path }}.backup"
+
+- name: Inject result
+  set_fact:
+    matrix_playbook_runtime_results: |
+      {{
+        matrix_playbook_runtime_results|default([])
+        +
+        [
+          "NOTE: Your SQLite database file has been imported into Postgres. The original file has been moved from `{{ sqlite_database_path }}` to `{{ sqlite_database_path }}.backup`. When you've confirmed that the import went well and everything works, you should be able to safely delete this file."
+        ]
+      }}

roles/matrix-postgres/tasks/import_postgres.yml

@@ -74,8 +74,8 @@
       {{ matrix_postgres_docker_image_latest }}
       -c "cat /{{ server_path_postgres_dump|basename }} |
       {{ 'gunzip |' if server_path_postgres_dump.endswith('.gz') else '' }}
-      grep -vE '^CREATE ROLE {{ matrix_postgres_connection_username }}' |
-      grep -vE '^CREATE DATABASE {{ matrix_postgres_db_name }}' |
+      grep -vE '{{ matrix_postgres_import_roles_ignore_regex }}' |
+      grep -vE '{{ matrix_postgres_import_databases_ignore_regex }}' |
       psql -v ON_ERROR_STOP=1 -h matrix-postgres"
 
 # This is a hack.

roles/matrix-postgres/tasks/main.yml

@@ -19,21 +19,24 @@
   tags:
     - import-postgres
 
-- import_tasks: "{{ role_path }}/tasks/import_sqlite_db.yml"
+# The `run_postgres_import_sqlite_db` variable had better be renamed to be consistent,
+# but that's a breaking change which may cause trouble for people.
+- import_tasks: "{{ role_path }}/tasks/import_synapse_sqlite_db.yml"
   when: run_postgres_import_sqlite_db|bool
   tags:
-    - import-sqlite-db
+    - import-synapse-sqlite-db
+
+# Perhaps we need a new variable here, instead of `run_postgres_import_sqlite_db`.
+- import_tasks: "{{ role_path }}/tasks/import_generic_sqlite_db.yml"
+  when: run_postgres_import_sqlite_db|bool
+  tags:
+    - import-generic-sqlite-db
 
 - import_tasks: "{{ role_path }}/tasks/upgrade_postgres.yml"
   when: run_postgres_upgrade|bool
   tags:
     - upgrade-postgres
 
-- import_tasks: "{{ role_path }}/tasks/run_synapse_janitor.yml"
-  when: run_postgres_synapse_janitor|bool
-  tags:
-    - run-postgres-synapse-janitor
-
 - import_tasks: "{{ role_path }}/tasks/run_vacuum.yml"
   when: run_postgres_vacuum|bool
   tags:

roles/matrix-postgres/tasks/run_synapse_janitor.yml

@@ -1,117 +0,0 @@
----
-
-# Pre-checks
-
-- name: Fail if Postgres not enabled
-  fail:
-    msg: "Postgres via the matrix-postgres role is not enabled (`matrix_postgres_enabled`). Cannot run synapse-janitor."
-  when: "not matrix_postgres_enabled|bool"
-
-- name: Fail if not aware of the risks
-  fail:
-    msg: >-
-      Using Synapse Janitor is considered dangerous and may break your database.
-      See https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/465.
-      If you'd like to run it anyway, add `--extra-vars='i_know_synapse_janitor_is_dangerous=1'` to your command.
-  when: "i_know_synapse_janitor_is_dangerous|default('') == ''"
-
-# Defaults
-
-- name: Set postgres_start_wait_time, if not provided
-  set_fact:
-    postgres_start_wait_time: 15
-  when: "postgres_start_wait_time|default('') == ''"
-
-- name: Set postgres_synapse_janitor_wait_time, if not provided
-  set_fact:
-    postgres_synapse_janitor_wait_time: "{{ 7 * 86400 }}"
-  when: "postgres_synapse_janitor_wait_time|default('') == ''"
-
-- name: Set postgres_synapse_janitor_tool_path, if not provided
-  set_fact:
-    postgres_synapse_janitor_tool_path: "{{ matrix_postgres_base_path }}/synapse_janitor.sql"
-  when: "postgres_synapse_janitor_tool_path|default('') == ''"
-
-
-# Actual janitor work
-
-- name: Download synapse-janitor tool
-  get_url:
-    url: "{{ matrix_postgres_tool_synapse_janitor }}"
-    dest: "{{ postgres_synapse_janitor_tool_path }}"
-    force: true
-    mode: 0550
-    owner: "{{ matrix_user_username }}"
-    group: "{{ matrix_user_groupname }}"
-
-- name: Ensure matrix-postgres is started
-  service:
-    name: matrix-postgres
-    state: started
-    daemon_reload: yes
-
-- name: Wait a bit, so that Postgres can start
-  wait_for:
-    timeout: "{{ postgres_start_wait_time }}"
-  delegate_to: 127.0.0.1
-  become: false
-
-- import_tasks: tasks/util/detect_existing_postgres_version.yml
-
-- name: Abort, if no existing Postgres version detected
-  fail:
-    msg: "Could not find existing Postgres installation"
-  when: "not matrix_postgres_detected_existing|bool"
-
-- name: Generate Postgres database synapse-janitor command
-  set_fact:
-    matrix_postgres_synapse_janitor_command: >-
-      {{ matrix_host_command_docker }} run --rm --name matrix-postgres-synapse-janitor
-      --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
-      --cap-drop=ALL
-      --network={{ matrix_docker_network }}
-      --env-file={{ matrix_postgres_base_path }}/env-postgres-psql
-      --mount type=bind,src={{ postgres_synapse_janitor_tool_path }},dst=/synapse_janitor.sql,ro=true
-      {{ matrix_postgres_docker_image_latest }}
-      psql -v ON_ERROR_STOP=1 -h matrix-postgres {{ matrix_synapse_database_database }} -f /synapse_janitor.sql
-
-- name: Note about Postgres purging alternative
-  debug:
-    msg: >-
-      Running synapse-janitor with the following Postgres command: `{{ matrix_postgres_synapse_janitor_command }}`.
-      If this crashes, you can stop all processes (`systemctl stop matrix-*`),
-      start Postgres only (`systemctl start matrix-postgres`)
-      and manually run the above command directly on the server.
-
-- name: Populate service facts
-  service_facts:
-
-- set_fact:
-    matrix_postgres_synapse_was_running: "{{ ansible_facts.services['matrix-synapse.service']|default(none) is not none and ansible_facts.services['matrix-synapse.service'].state == 'running' }}"
-
-- name: Ensure matrix-synapse is stopped
-  service:
-    name: matrix-synapse
-    state: stopped
-    daemon_reload: yes
-
-- name: Run synapse-janitor
-  command: "{{ matrix_postgres_synapse_janitor_command }}"
-  async: "{{ postgres_synapse_janitor_wait_time }}"
-  poll: 10
-  register: matrix_postgres_synapse_janitor_result
-
-# Intentionally show the results
-- debug: var="matrix_postgres_synapse_janitor_result"
-
-- name: Ensure matrix-synapse is started, if it previously was
-  service:
-    name: matrix-synapse
-    state: started
-    daemon_reload: yes
-  when: "matrix_postgres_synapse_was_running|bool"
-
-- name: Delete synapse-janitor tool
-  file:
-    path: "{{ postgres_synapse_janitor_tool_path }}"
-    state: absent

roles/matrix-postgres/tasks/setup_postgres.yml

@@ -113,6 +113,13 @@
     daemon_reload: yes
   when: "matrix_postgres_enabled|bool and matrix_postgres_systemd_service_result.changed"
 
+- include_tasks:
+    file: "{{ role_path }}/tasks/util/create_additional_databases.yml"
+    apply:
+      tags:
+        - always
+  when: "matrix_postgres_enabled|bool and matrix_postgres_additional_databases|length > 0"
+
 #
 # Tasks related to getting rid of the internal postgres server (if it was previously enabled)
 #

roles/matrix-postgres/tasks/upgrade_postgres.yml

@@ -135,8 +135,8 @@
       {{ matrix_postgres_docker_image_latest }}
       -c "cat /in/{{ postgres_dump_name }} |
       {{ 'gunzip |' if postgres_dump_name.endswith('.gz') else '' }}
-      grep -vE '^CREATE ROLE {{ matrix_postgres_connection_username }}' |
-      grep -vE '^CREATE DATABASE {{ matrix_postgres_db_name }}' |
+      grep -vE '{{ matrix_postgres_import_roles_ignore_regex }}' |
+      grep -vE '{{ matrix_postgres_import_databases_ignore_regex }}' |
       psql -v ON_ERROR_STOP=1 -h matrix-postgres"
 
 # This is a hack.

roles/matrix-postgres/tasks/util/create_additional_database.yml

@@ -0,0 +1,40 @@
+---
+
+# It'd be better if this is belonged to `validate_config.yml`, but it would have to be some loop-within-a-loop there,
+# and that's ugly. We also don't expect this to catch errors often. It's more of a defensive last-minute check.
+- name: Fail if additional database data appears invalid
+  fail:
+    msg: "Additional database definition ({{ additional_db }} lacks a required key: {{ item }}"
+  when: "item not in additional_db"
+  with_items: "{{ ['name', 'username', 'password'] }}"
+
+# The SQL statements that we'll run against Postgres are stored in a file that others can't read.
+# This file will be mounted into the container and fed to Postgres.
+# This way, we avoid passing sensitive data around in CLI commands that other users on the system can see.
+- name: Create additional database initialization SQL file for {{ additional_db.name }}
+  template:
+    src: "{{ role_path }}/templates/sql/init-additional-db-user-and-role.sql.j2"
+    dest: "/tmp/matrix-postgres-init-additional-db-user-and-role.sql"
+    mode: 0600
+    owner: "{{ matrix_user_uid }}"
+    group: "{{ matrix_user_gid }}"
+
+- name: Execute Postgres additional database initialization SQL file for {{ additional_db.name }}
+  command:
+    cmd: >-
+      {{ matrix_host_command_docker }} run
+      --rm
+      --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
+      --cap-drop=ALL
+      --env-file={{ matrix_postgres_base_path }}/env-postgres-psql
+      --network {{ matrix_docker_network }}
+      --mount type=bind,src=/tmp/matrix-postgres-init-additional-db-user-and-role.sql,dst=/matrix-postgres-init-additional-db-user-and-role.sql,ro
+      --entrypoint=/bin/sh
+      {{ matrix_postgres_docker_image_to_use }}
+      -c
+      'psql -h {{ matrix_postgres_connection_hostname }} --file=/matrix-postgres-init-additional-db-user-and-role.sql'
+
+- name: Delete additional database initialization SQL file for {{ additional_db.name }}
+  file:
+    path: /tmp/matrix-postgres-init-additional-db-user-and-role.sql
+    state: absent

roles/matrix-postgres/tasks/util/create_additional_databases.yml

@@ -0,0 +1,23 @@
+---
+
+- name: Ensure matrix-postgres is started
+  service:
+    name: matrix-postgres
+    state: started
+    daemon_reload: yes
+  register: matrix_postgres_service_start_result
+
+- name: Wait a bit, so that Postgres can start
+  wait_for:
+    timeout: "{{ matrix_postgres_additional_databases_postgres_start_wait_timeout_seconds }}"
+  delegate_to: 127.0.0.1
+  become: false
+  when: "matrix_postgres_service_start_result.changed|bool"
+
+- name: Create additional Postgres user and database
+  include_tasks: "{{ role_path }}/tasks/util/create_additional_database.yml"
+  with_items: "{{ matrix_postgres_additional_databases }}"
+  loop_control:
+    loop_var: additional_db
+  # Suppress logging to avoid dumping the credentials to the shell
+  no_log: true

roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml

@@ -0,0 +1,168 @@
+---
+
+- name: Fail if Postgres not enabled
+  fail:
+    msg: "Postgres via the matrix-postgres role is not enabled (`matrix_postgres_enabled`). Cannot migrate."
+  when: "not matrix_postgres_enabled|bool"
+
+- name: Fail if util called incorrectly (missing matrix_postgres_db_migration_request)
+  fail:
+    msg: "The `matrix_postgres_db_migration_request` variable needs to be provided to this util."
+  when: "matrix_postgres_db_migration_request is not defined"
+
+- name: Fail if util called incorrectly (invalid matrix_postgres_db_migration_request)
+  fail:
+    msg: "The `matrix_postgres_db_migration_request` variable needs to contain `{{ item }}`."
+  with_items:
+    - src
+    - dst
+    - caller
+    - engine_variable_name
+    - systemd_services_to_stop
+  when: "item not in matrix_postgres_db_migration_request"
+
+- name: Check if the provided source database file exists
+  stat:
+    path: "{{ matrix_postgres_db_migration_request.src }}"
+  register: matrix_postgres_db_migration_request_src_stat_result
+
+- name: Fail if provided source database file doesn't exist
+  fail:
+    msg: "File cannot be found on the server at {{ matrix_postgres_db_migration_request.src }}"
+  when: "not matrix_postgres_db_migration_request_src_stat_result.stat.exists"
+
+- block:
+    - name: Ensure pgloader repository is present on self-build
+      git:
+        repo: "{{ matrix_postgres_pgloader_container_image_self_build_repo }}"
+        dest: "{{ matrix_postgres_pgloader_container_image_self_build_src_path }}"
+        version: "{{ matrix_postgres_pgloader_container_image_self_build_repo_branch }}"
+        force: "yes"
+      register: matrix_postgres_pgloader_git_pull_results
+
+    # If `stable` is used, we hit an error when processing /opt/src/pgloader/build/quicklisp/dists/quicklisp/software/uax-15-20201220-git/data/CompositionExclusions.txt:
+    # > the octet sequence #(194) cannot be decoded
+    #
+    # The issue is described here and is not getting fixed for months: https://github.com/dimitri/pgloader/pull/1179
+    #
+    # Although we're not using the dimitri/pgloader image, the one we're using suffers from the same problem.
+    - name: Switch pgloader base image from Debian stable (likely 10.x/Buster) to Bullseye
+      lineinfile:
+        path: "{{ matrix_postgres_pgloader_container_image_self_build_src_path }}/Dockerfile"
+        regexp: "{{ item.match }}"
+        line: "{{ item.replace }}"
+      with_items:
+        - match: '^FROM debian:stable-slim as builder$'
+          replace: 'FROM debian:bullseye-slim as builder'
+        - match: '^FROM debian:stable-slim$'
+          replace: 'FROM debian:bullseye-slim'
+
+    - name: Ensure pgloader Docker image is built
+      docker_image:
+        name: "{{ matrix_postgres_pgloader_docker_image }}"
+        source: build
+        force_source: "{{ matrix_postgres_pgloader_git_pull_results.changed }}"
+        build:
+          dockerfile: Dockerfile
+          path: "{{ matrix_postgres_pgloader_container_image_self_build_src_path }}"
+          pull: yes
+  when: "matrix_postgres_pgloader_container_image_self_build|bool"
+
+- name: Ensure pgloader Docker image is pulled
+  docker_image:
+    name: "{{ matrix_postgres_pgloader_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_postgres_pgloader_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_pgloader_docker_image_force_pull }}"
+  when: "not matrix_postgres_pgloader_container_image_self_build"
+
+# Defaults
+
+- name: Set postgres_start_wait_time, if not provided
+  set_fact:
+    postgres_start_wait_time: 15
+  when: "postgres_start_wait_time|default('') == ''"
+
+# Actual import work
+
+# matrix-postgres is most likely started already
+- name: Ensure matrix-postgres is started
+  service:
+    name: matrix-postgres
+    state: started
+    daemon_reload: yes
+  register: matrix_postgres_service_start_result
+
+- name: Wait a bit, so that Postgres can start
+  wait_for:
+    timeout: "{{ postgres_start_wait_time }}"
+  delegate_to: 127.0.0.1
+  become: false
+  when: "matrix_postgres_service_start_result.changed|bool"
+
+# We only stop services here, leaving it to the caller to start them later.
+#
+# We can't start them, because they probably need to be reconfigured too (changing the configuration from using SQLite to Postgres, etc.),
+# before starting.
+#
+# Since the caller will be starting them, it might make sense to leave stopping to it as well.
+# However, we don't do it, because it's simpler having it here, and it also gets to happen only if we'll be doing an import.
+# If we bailed out (somewhere above), nothing would have gotten stopped. It's nice to leave this running in such cases.
+- name: Ensure systemd services blocking the database import are stopped
+  service:
+    name: "{{ item }}"
+    state: stopped
+  failed_when: false
+  with_items: "{{ matrix_postgres_db_migration_request.systemd_services_to_stop }}"
+
+- name: Import {{ matrix_postgres_db_migration_request.engine_old }} database from {{ matrix_postgres_db_migration_request.src }} into Postgres
+  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_postgres_db_migration_request.src }},dst=/in.db,ro
+      --entrypoint=/bin/sh
+      {{ matrix_postgres_pgloader_docker_image }}
+      -c
+      'pgloader {{ matrix_postgres_db_migration_request.pgloader_options|default([])|join(' ') }} /in.db {{ matrix_postgres_db_migration_request.dst }}'
+
+- block:
+    # We can't use `{{ role_path }}` here, neither with `import_tasks`, nor with `include_tasks`,
+    # because it refers to the role that included this util, and not to the role this file belongs to.
+    - import_tasks: "{{ role_path }}/../matrix-postgres/tasks/util/detect_existing_postgres_version.yml"
+
+    - set_fact:
+        matrix_postgres_docker_image_to_use: "{{ matrix_postgres_docker_image_latest if matrix_postgres_detected_version_corresponding_docker_image == '' else matrix_postgres_detected_version_corresponding_docker_image }}"
+
+    - name: Execute additional Postgres SQL migration statements
+      command:
+        cmd: >-
+          {{ matrix_host_command_docker }} run
+          --rm
+          --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
+          --cap-drop=ALL
+          --env-file={{ matrix_postgres_base_path }}/env-postgres-psql
+          --network={{ matrix_docker_network }}
+          {{ matrix_postgres_docker_image_to_use }}
+          psql --host=matrix-postgres --dbname={{ matrix_postgres_db_migration_request.additional_psql_statements_db_name }} --command='{{ item }}'
+      with_items: "{{ matrix_postgres_db_migration_request.additional_psql_statements_list }}"
+
+  when: "matrix_postgres_db_migration_request.additional_psql_statements_list|default([])|length > 0"
+
+- name: Archive {{ matrix_postgres_db_migration_request.engine_old }} database ({{ matrix_postgres_db_migration_request.src }} -> {{ matrix_postgres_db_migration_request.src }}.backup)
+  command:
+    cmd: "mv {{ matrix_postgres_db_migration_request.src }} {{ matrix_postgres_db_migration_request.src }}.backup"
+
+- name: Inject result
+  set_fact:
+    matrix_playbook_runtime_results: |
+      {{
+        matrix_playbook_runtime_results|default([])
+        +
+        [
+          "NOTE: Your {{ matrix_postgres_db_migration_request.engine_old }} database file has been imported into Postgres. The original database file has been moved from `{{ matrix_postgres_db_migration_request.src }}` to `{{ matrix_postgres_db_migration_request.src }}.backup`. When you've confirmed that the import went well and everything works, you should be able to safely delete this file."
+        ]
+      }}

roles/matrix-postgres/templates/sql/init-additional-db-user-and-role.sql.j2

@@ -0,0 +1,19 @@
+-- `CREATE USER` does not support `IF NOT EXISTS`, so we use this workaround to prevent an error and raise a notice instead.
+-- Seen here: https://stackoverflow.com/a/49858797
+DO $$
+BEGIN
+  CREATE USER {{ additional_db.username }};
+  EXCEPTION WHEN DUPLICATE_OBJECT THEN
+  RAISE NOTICE 'not creating user {{ additional_db.username }}, since it already exists';
+END
+$$;
+
+-- This is useful for initial user creation (since we don't assign a password above) and for handling subsequent password changes
+-- TODO - we should escape quotes in the password.
+ALTER ROLE {{ additional_db.username }} PASSWORD '{{ additional_db.password }}';
+
+-- This will generate an error on subsequent execution
+CREATE DATABASE {{ additional_db.name }} WITH LC_CTYPE 'C' LC_COLLATE 'C' OWNER {{ additional_db.username }};
+
+-- This is useful for changing the database owner subsequently
+ALTER DATABASE {{ additional_db.name }} OWNER TO {{ additional_db.username }};

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

@@ -3,6 +3,7 @@
 Description=Matrix Postgres server
 After=docker.service
 Requires=docker.service
+DefaultDependencies=no
 
 [Service]
 Type=simple