From 573f1df7850dc3a05913c4a3a67470aeb9018f0b Mon Sep 17 00:00:00 2001
From: transcaffeine <transcaffeine@finally.coffee>
Date: Thu, 14 Nov 2024 18:38:38 +0100
Subject: [PATCH] feat(postgresql): add ansible role for postgresql deployment

---
 README.md                                     |  3 +
 galaxy.yml                                    |  2 +
 playbooks/postgresql.yml                      |  6 ++
 roles/postgresql/README.md                    |  4 ++
 roles/postgresql/defaults/main/config.yml     | 17 +++++
 roles/postgresql/defaults/main/container.yml  | 60 +++++++++++++++++
 roles/postgresql/defaults/main/main.yml       | 34 ++++++++++
 roles/postgresql/defaults/main/user.yml       | 10 +++
 roles/postgresql/handlers/main.yml            | 12 ++++
 roles/postgresql/meta/main.yml                | 12 ++++
 roles/postgresql/tasks/configure.yml          | 49 ++++++++++++++
 roles/postgresql/tasks/deploy-docker.yml      | 47 +++++++++++++
 roles/postgresql/tasks/initialize-docker.yml  | 48 +++++++++++++
 roles/postgresql/tasks/main.yml               | 67 +++++++++++++++++++
 roles/postgresql/tasks/prepare.yml            | 33 +++++++++
 .../postgresql/templates/postgresql-passwd.j2 | 19 ++++++
 roles/postgresql/vars/main.yml                |  6 ++
 17 files changed, 429 insertions(+)
 create mode 100644 playbooks/postgresql.yml
 create mode 100644 roles/postgresql/README.md
 create mode 100644 roles/postgresql/defaults/main/config.yml
 create mode 100644 roles/postgresql/defaults/main/container.yml
 create mode 100644 roles/postgresql/defaults/main/main.yml
 create mode 100644 roles/postgresql/defaults/main/user.yml
 create mode 100644 roles/postgresql/handlers/main.yml
 create mode 100644 roles/postgresql/meta/main.yml
 create mode 100644 roles/postgresql/tasks/configure.yml
 create mode 100644 roles/postgresql/tasks/deploy-docker.yml
 create mode 100644 roles/postgresql/tasks/initialize-docker.yml
 create mode 100644 roles/postgresql/tasks/main.yml
 create mode 100644 roles/postgresql/tasks/prepare.yml
 create mode 100644 roles/postgresql/templates/postgresql-passwd.j2
 create mode 100644 roles/postgresql/vars/main.yml

diff --git a/README.md b/README.md
index 6195bf7..27876af 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,9 @@
 - [`mariadb`](roles/mariadb/README.md): deploy mariadb
   in a docker container
 
+- [`postgresql`](roles/postgresql/README.md): deploy postgresql,
+  the worlds most advances open-source relational database
+
 - [`valkey`](roles/valkey/README.md): deploy and configure valkey,
   an open source in-memory data store under BSD license, forked
   from redis.
diff --git a/galaxy.yml b/galaxy.yml
index 9eda0ba..845b873 100644
--- a/galaxy.yml
+++ b/galaxy.yml
@@ -16,5 +16,7 @@ tags:
   - elasticsearch
   - redis
   - mariadb
+  - postgresql
+  - postgres
   - valkey
   - docker
diff --git a/playbooks/postgresql.yml b/playbooks/postgresql.yml
new file mode 100644
index 0000000..1c0d7ac
--- /dev/null
+++ b/playbooks/postgresql.yml
@@ -0,0 +1,6 @@
+---
+- name: Deploy and configure PostgreSQL
+  hosts: "{{ postgresql_hosts | default('postgresql', true) }}"
+  become: "{{ postgresql_become | default(true, true) }}"
+  roles:
+    - role: finallycoffee.databases.postgresql
diff --git a/roles/postgresql/README.md b/roles/postgresql/README.md
new file mode 100644
index 0000000..c037305
--- /dev/null
+++ b/roles/postgresql/README.md
@@ -0,0 +1,4 @@
+# `finallycoffee.databases.postgresql` ansible role
+
+PostgreSQL is the self proclaimed "world's most advanced" open source relational
+database. This ansible role can deploy and configure postgresql.
diff --git a/roles/postgresql/defaults/main/config.yml b/roles/postgresql/defaults/main/config.yml
new file mode 100644
index 0000000..0badb94
--- /dev/null
+++ b/roles/postgresql/defaults/main/config.yml
@@ -0,0 +1,17 @@
+---
+postgresql_config_connect_socket: true
+postgresql_config_unix_socket_directories:
+  - "/var/run/postgresql"
+postgresql_config_listen_addresses:
+  - '*'
+postgresql_config_port: 5432
+
+postgresql_base_config:
+  listen_addresses: "{{ postgresql_config_listen_addresses }}"
+  connect_socket: "{{ postgresql_config_connect_socket }}"
+  port: "{{ postgresql_config_port }}"
+postgresql_merged_config: >-2
+  {{ postgresql_base_config | combine(
+    postgresql_config | default({}, true),
+    recursive=True
+  ) }}
diff --git a/roles/postgresql/defaults/main/container.yml b/roles/postgresql/defaults/main/container.yml
new file mode 100644
index 0000000..7600746
--- /dev/null
+++ b/roles/postgresql/defaults/main/container.yml
@@ -0,0 +1,60 @@
+---
+postgresql_container_image_registry: docker.io
+postgresql_container_image_namespace: ~
+postgresql_container_image_name: postgres
+postgresql_container_image_tag: ~
+postgresql_container_image_source: pull
+postgresql_container_image_force_source: >-2
+  {{ postgresql_container_image_tag | default(false, true) | bool }}
+postgresql_container_image: >-2
+  {{
+    ([
+      postgresql_container_image_registry | default([], true),
+      postgresql_container_image_namespace | default([], true),
+      postgresql_container_image_name
+    ] | flatten | join('/'))
+    + ':' + postgresql_container_image_tag | default(
+      postgresql_version + (
+        ((postgresql_container_image_flavour is string)
+          and (postgresql_container_image_flavour | length > 0))
+        | ternary(
+          '_' + postgresql_container_image_flavour | default('', true),
+          '',
+        )
+      ),
+      true
+    )
+  }}
+
+postgresql_container_name: "postgresql-{{ postgresql_major_version }}"
+postgresql_container_env: ~
+postgresql_container_user: >-2
+  {{ postgresql_user_id }}:{{ postgresql_user_group_id }}
+postgresql_container_ports: ~
+postgresql_container_labels: ~
+postgresql_container_networks: ~
+postgresql_container_recreate: ~
+postgresql_container_etc_hosts: ~
+postgresql_container_restart_policy: "on-failure"
+postgresql_container_state: >-2
+  {{ (postgresql_state == 'present') | ternary('started', 'absent') }}
+postgresql_container_volumes: ~
+postgresql_container_base_volumes:
+  - "{{ postgresql_data_path }}:{{ postgresql_container_data_dir }}:z"
+  - "{{ postgresql_pg_hba_conf_file }}:{{ postgresql_container_data_dir }}/pg_hba.conf:ro"
+  - "{{ postgresql_pg_ident_conf_file }}:{{ postgresql_container_data_dir }}/pg_ident.conf:ro"
+  - "{{ postgresql_container_passwd_file }}:/etc/passwd:ro"
+postgresql_container_merged_volumes: >-2
+  {{ postgresql_container_base_volumes
+    + (postgresql_container_volumes | default([], true)) }}
+
+# (Memory) performance tuning
+postgresql_container_memory: ~
+postgresql_container_memory_reservation: ~
+postgresql_container_shm_size: ~
+postgresql_container_oom_kill: ~
+postgresql_container_oom_score_adj: ~
+postgresql_container_ulimits: ~
+
+postgresql_container_passwd_file: "{{ postgresql_config_path }}/passwd"
+postgresql_container_data_dir: "/var/lib/postgresql/data"
diff --git a/roles/postgresql/defaults/main/main.yml b/roles/postgresql/defaults/main/main.yml
new file mode 100644
index 0000000..21ed761
--- /dev/null
+++ b/roles/postgresql/defaults/main/main.yml
@@ -0,0 +1,34 @@
+---
+postgresql_user: postgresql
+postgresql_version: >-2
+  {{ postgresql_versions[postgresql_major_version | string] }}
+postgresql_major_version: 16
+postgresql_versions:
+  "17": "17.2"
+  "16": "16.6"
+  "15": "15.10"
+  "14": "14.15"
+
+postgresql_config_path: >-2
+  /etc/postgresql/{{ postgresql_major_version }}
+postgresql_data_path: >-2
+  /var/lib/postgresql/{{ postgresql_major_version }}
+postgresql_pg_ident_conf_file: >-2
+  {{ postgresql_config_path }}/pg_ident.conf
+postgresql_pg_hba_conf_file: >-2
+  {{ postgresql_config_path }}/pg_hba.conf
+postgresql_admin_role: "{{ postgresql_user }}"
+postgresql_admin_role_contype: local
+postgresql_admin_role_method: peer
+postgresql_admin_local_user: >-2
+  {{ ansible_facts['user_id'] }}
+postgresql_admin_role_mapping_name: >-2
+  {{ postgresql_admin_local_user }}_{{ postgresql_admin_role }}
+postgresql_admin_pg_ident_conf: >-2
+  {{ postgresql_admin_role_mapping_name }}\t{{ postgresql_admin_local_user }}\t{{ postgresql_admin_role }}
+postgresql_admin_pg_hba_conf_options: >-2
+  map={{ postgresql_admin_role_mapping_name }}
+postgresql_superuser_password: ~
+
+postgresql_state: present
+postgresql_deployment_method: docker
diff --git a/roles/postgresql/defaults/main/user.yml b/roles/postgresql/defaults/main/user.yml
new file mode 100644
index 0000000..d28fa5a
--- /dev/null
+++ b/roles/postgresql/defaults/main/user.yml
@@ -0,0 +1,10 @@
+---
+postgresql_user_system: true
+postgresql_user_create_home: false
+postgresql_user_groups: ~
+postgresql_user_append: ~
+
+postgresql_user_id: >-2
+  {{ postgresql_user_info.uid | default(postgresql_user, true) }}
+postgresql_user_group_id: >-2
+  {{ postgresql_user_info.group | default(postgresql_user, true) }}
diff --git a/roles/postgresql/handlers/main.yml b/roles/postgresql/handlers/main.yml
new file mode 100644
index 0000000..afbf59f
--- /dev/null
+++ b/roles/postgresql/handlers/main.yml
@@ -0,0 +1,12 @@
+---
+- name: Restart postgresql container '{{ postgresql_container_name }}' (docker)
+  community.docker.docker_container:
+    name: "{{ postgresql_container_name }}"
+    state: "{{ postgresql_container_state }}"
+    restart: true
+    comparisons:
+      '*': "ignore"
+  when:
+    - postgresql_deployment_method == 'docker'
+    - postgresql_container_state not in ['absent', 'stopped']
+  listen: postgresql_restart
diff --git a/roles/postgresql/meta/main.yml b/roles/postgresql/meta/main.yml
new file mode 100644
index 0000000..2eb937c
--- /dev/null
+++ b/roles/postgresql/meta/main.yml
@@ -0,0 +1,12 @@
+---
+allow_duplicates: true
+dependencies: []
+galaxy_info:
+  role_name: postgresql
+  description: >-2
+    PostgreSQL is the self-proclaimed 'worlds most advanced' open source relational database
+  galaxy_tags:
+    - postgresql
+    - postgres
+    - database
+    - docker
diff --git a/roles/postgresql/tasks/configure.yml b/roles/postgresql/tasks/configure.yml
new file mode 100644
index 0000000..56b147e
--- /dev/null
+++ b/roles/postgresql/tasks/configure.yml
@@ -0,0 +1,49 @@
+---
+- name: Ensure postgresql superuser is set
+  community.postgresql.postgresql_user:
+    name: "{{ postgresql_admin_role }}"
+    password: "{{ postgresql_superuser_password }}"
+    login_host: >-2
+      {{
+        (postgresql_config_unix_socket_directories | first)
+        if postgresql_config_connect_socket else 
+        (postgresql_container_info.container.NetworkSettings.IPAddress)
+      }}
+  register: postgresql_superuser_password_result
+  until: "postgresql_superuser_password_result is succeeded"
+  retries: 10
+  delay: 2
+
+- name: Ensure postgresql configuration is set
+  community.postgresql.postgresql_set:
+    name: "{{ option.key }}"
+    value: "{{ option.value }}"
+    login_host: >-2
+      {{
+        (postgresql_config_unix_socket_directories | first)
+        if postgresql_config_connect_socket else 
+        (postgresql_container_info.container.NetworkSettings.IPAddress)
+      }}
+    login_port: "{{ postgresql_config_port }}"
+    login_password: #TODO
+  loop: "{{ postgresql_merged_options | dict2items }}"
+  loop_control:
+    loop_var: option
+
+- name: Ensure postgresql configuration is reloaded
+  community.postgresql.postgresql_query:
+    query: "SELECT pg_reload_conf();"
+    login_host: #TODO
+    login_port: #TODO
+    login_password: #TODO
+
+- name: Ensure restart handler is fired if required
+  debug:
+    msg: "{{ result.option.key }} changed! Restart required: {{ result.restart_required }}"
+  when: result.changed
+  changed_when: "{{ result.restart_required }}"
+  notify: postgresql_restart
+  loop: "{{ postgresql_config_results }}"
+  loop_control:
+    loop_var: result
+    label: "{{ result.option.name }}"
diff --git a/roles/postgresql/tasks/deploy-docker.yml b/roles/postgresql/tasks/deploy-docker.yml
new file mode 100644
index 0000000..d37d8c8
--- /dev/null
+++ b/roles/postgresql/tasks/deploy-docker.yml
@@ -0,0 +1,47 @@
+---
+- name: Ensure postgresql container image '{{ postgresql_container_image }}' is {{ postgresql_state }}
+  community.docker.docker_image:
+    name: "{{ postgresql_container_image }}"
+    state: "{{ postgresql_state }}"
+    source: "{{ postgresql_container_image_source }}"
+    force_source: "{{ postgresql_container_image_force_source }}"
+  register: postgresql_container_image_info
+  until: postgresql_container_image_info is success
+  retries: 5
+  delay: 4
+
+- name: Ensure /etc/passwd for container is {{ postgresql_state }}
+  ansible.builtin.template:
+    src: "postgresql-passwd.j2"
+    dest: "{{ postgresql_container_passwd_file }}"
+    owner: "{{ postgresql_user_id }}"
+    group: "{{ postgresql_user_group_id }}"
+    mode: "0640"
+  when: postgresql_state == 'present'
+
+- name: Initialize database if empty
+  ansible.builtin.include_tasks:
+    file: "initialize-docker.yml"
+  when:
+    - postgresql_state == 'present'
+
+- name: Ensure postgresql container '{{ postgresql_container_name }}' is {{ postgresql_container_state }}
+  community.docker.docker_container:
+    name: "{{ postgresql_container_name }}"
+    image: "{{ postgresql_container_image }}"
+    env: "{{ postgresql_container_env | default(omit, true) }}"
+    user: "{{ postgresql_container_user | default(omit, true) }}"
+    ports: "{{ postgresql_container_ports | default(omit, true) }}"
+    labels: "{{ postgresql_container_labels | default(omit, true) }}"
+    volumes: "{{ postgresql_container_merged_volumes }}"
+    recreate: "{{ postgresql_container_recreate | default(omit, true) }}"
+    networks: "{{ postgresql_container_networks | default(omit, true) }}"
+    etc_hosts: "{{ postgresql_container_etc_hosts | default(omit, true) }}"
+    memory: "{{ postgresql_container_memory | default(omit, true) }}"
+    memory_reservation: "{{ postgresql_container_memory_reservation | default(omit, true) }}"
+    oom_killer: "{{ postgresql_container_oom_killer | default(omit, true) }}"
+    oom_score_adj: "{{ postgresql_container_oom_score_adj | default(omit, true) }}"
+    shm_size: "{{ postgresql_container_shm_size | default(omit, true) }}"
+    ulimits: "{{ postgresql_container_ulimits | default(omit, true) }}"
+    restart_policy: "{{ postgresql_container_restart_policy | default(omit, true) }}"
+    state: "{{ postgresql_container_state }}"
diff --git a/roles/postgresql/tasks/initialize-docker.yml b/roles/postgresql/tasks/initialize-docker.yml
new file mode 100644
index 0000000..5325ced
--- /dev/null
+++ b/roles/postgresql/tasks/initialize-docker.yml
@@ -0,0 +1,48 @@
+---
+- name: Ensure container '{{ postgresql_container_name }}' is {{ postgresql_container_state }} to initialise the database
+  community.docker.docker_container:
+    name: "{{ postgresql_container_name }}"
+    image: "{{ postgresql_container_image }}"
+    env: >-2
+      {{ postgresql_container_env | default({}, true)
+         | combine({'POSTGRES_PASSWORD': postgresql_superuser_password}) }}
+    user: "{{ postgresql_container_user | default(omit, true) }}"
+    ports: "{{ postgresql_container_ports | default(omit, true) }}"
+    labels: "{{ postgresql_container_labels | default(omit, true) }}"
+    volumes: "{{ postgresql_container_merged_volumes }}"
+    recreate: "{{ postgresql_container_recreate | default(omit, true) }}"
+    networks: "{{ postgresql_container_networks | default(omit, true) }}"
+    etc_hosts: "{{ postgresql_container_etc_hosts | default(omit, true) }}"
+    memory: "{{ postgresql_container_memory | default(omit, true) }}"
+    memory_reservation: "{{ postgresql_container_memory_reservation | default(omit, true) }}"
+    oom_killer: "{{ postgresql_container_oom_killer | default(omit, true) }}"
+    oom_score_adj: "{{ postgresql_container_oom_score_adj | default(omit, true) }}"
+    shm_size: "{{ postgresql_container_shm_size | default(omit, true) }}"
+    ulimits: "{{ postgresql_container_ulimits | default(omit, true) }}"
+    restart_policy: "{{ postgresql_container_restart_policy | default(omit, true) }}"
+    state: "{{ postgresql_container_state }}"
+  register: postgresql_container_info
+
+- name: Wait for container startup
+  block:
+    - name: Wait for container startup (socket)
+      ansible.builtin.wait_for:
+        path: "{{ postgresql_config_unix_socket_directories | first  }}.s.PGSQL.{{ postgresql_config_port }}"
+      when: "postgresql_config_connect_socket | bool"
+    - name: Wait for container startup (port)
+      ansible.builtin.wait_for:
+        host: >-2
+          {{ (pg_addresses == '*') | ternary(
+                 omit,
+                 postgresql_config_listen_addresses | first
+             ) }}
+        port: "{{ postgresql_config_port }}"
+      when: "not postgresql_config_connect_socket | bool"
+      vars:
+        pg_addresses: "{{ postgresql_config_listen_addresses | join(',') }}"
+
+- name: Ensure init container '{{ postgresql_container_name }}' is removed
+  community.docker.docker_container:
+    name: "{{ postgresql_container_name }}"
+    state: absent
+
diff --git a/roles/postgresql/tasks/main.yml b/roles/postgresql/tasks/main.yml
new file mode 100644
index 0000000..1e60504
--- /dev/null
+++ b/roles/postgresql/tasks/main.yml
@@ -0,0 +1,67 @@
+---
+- name: Ensure state is valid
+  ansible.builtin.fail:
+    msg: >-2
+      Invalid state '{{ postgresql_state }}'! Supported
+      states are {{ postgresql_states | join(', ') }}.
+  when: postgresql_state not in postgresql_states
+
+- name: Ensure deployment method is valid
+  ansible.builtin.fail:
+    msg: >-2
+      Unsupported deployment method '{{ postgresql_deployment_method }}!
+      Supported deployment methods are {{ postgresql_deployment_methods | join(', ') }}.
+  when: postgresql_deployment_method not in postgresql_deployment_methods
+
+- name: Ensure postgresql user '{{ postgresql_user }}' is {{ postgresql_state }}
+  ansible.builtin.user:
+    name: "{{ postgresql_user }}"
+    state: "{{ postgresql_state }}"
+    system: "{{ postgresql_user_system | default(omit, true) }}"
+    create_home: "{{ postgresql_user_create_home | default(omit, true) }}"
+    groups: "{{ postgresql_user_groups | default(omit, true) }}"
+    append: "{{ postgresql_user_append | default(omit, true) }}"
+  register: postgresql_user_info
+
+- name: Ensure directories are {{ postgresql_state }}
+  ansible.builtin.file:
+    path: "{{ path.name }}"
+    state: "{{ (postgresql_state == 'present') | ternary('directory', 'absent') }}"
+    owner: "{{ path.owner | default(postgresql_user_id, true) }}"
+    group: "{{ path.group | default(postgresql_user_group_id, true) }}"
+    mode: "{{ path.mode | default('0755', true) }}"
+  loop:
+    - name: "{{ postgresql_config_path }}"
+    - name: "{{ postgresql_data_path }}"
+  loop_control:
+    loop_var: path
+    label: "{{ path.name }}"
+
+- name: Check for existing PG_VERSION file
+  ansible.builtin.stat:
+    path: "{{ postgresql_data_path }}/PG_VERSION"
+  register: postgresql_data_dir_version_info
+
+- name: Read existing PG_VERSION file
+  ansible.builtin.slurp:
+    path: "{{ postgresql_data_path }}/PG_VERSION"
+  register: postgresql_data_dir_version_content
+  when:
+    - postgresql_data_dir_version_info.stat.exists
+
+- name: Prevent major version changes
+  ansible.builtin.fail:
+    msg: >-2
+      Mismatched postgresql version for the data directory!
+      Aborting...
+  when:
+    - postgresql_data_dir_version_info.stat.exists
+    - "(postgresql_data_dir_version_content | b64decode | int) != (postgresql_major_version | int)"
+
+- name: Prepare authentication and authorization for database admin role
+  ansible.builtin.include_tasks:
+    file: "prepare.yml"
+
+- name: Deploy postgresql using {{ postgresql_deployment_method }}
+  ansible.builtin.include_tasks:
+    file: "deploy-{{ postgresql_deployment_method }}.yml"
diff --git a/roles/postgresql/tasks/prepare.yml b/roles/postgresql/tasks/prepare.yml
new file mode 100644
index 0000000..5e4f203
--- /dev/null
+++ b/roles/postgresql/tasks/prepare.yml
@@ -0,0 +1,33 @@
+---
+- name: Ensure postgresql config files are {{ postgresql_state }}
+  ansible.builtin.lineinfile:
+    path: "{{ file.name }}"
+    insertafter: "{{ file.insert_after | default(omit) }}"
+    insertbefore: "{{ file.insert_before | default(omit) }}"
+    line: "{{ file.line }}"
+    owner: "{{ postgresql_user_id }}"
+    group: "{{ postgresql_user_group_id }}"
+    create: true
+  loop_control:
+    loop_var: file
+    label: "{{ file.name }}"
+  loop:
+    - name: "{{ postgresql_pg_hba_conf_file }}"
+      insert_before: "BOF"
+      line: "# Ansible managed"
+    - name: "{{ postgresql_pg_ident_conf_file }}"
+      insert_before: "BOF"
+      line: "# Ansible managed"
+    - name: "{{ postgresql_pg_ident_conf_file }}"
+      insert_after: "# Ansible managed"
+      line: "{{ ansible_user }}_{{ postgresql_admin_role }}\t{{ ansible_user }}\t{{ postgresql_admin_role }}"
+  when: postgresql_state == 'present'
+
+- name: Configure permissions for postgresql admin role
+  community.postgresql.postgresql_pg_hba:
+    dest: "{{ postgresql_pg_hba_conf_file }}"
+    contype: "{{ postgresql_admin_role_contype }}"
+    users: "{{ postgresql_admin_role }}"
+    method: "{{ postgresql_admin_role_method }}"
+    options: "map={{ ansible_user }}_{{ postgresql_admin_role }}"
+  when: postgresql_state == 'present'
diff --git a/roles/postgresql/templates/postgresql-passwd.j2 b/roles/postgresql/templates/postgresql-passwd.j2
new file mode 100644
index 0000000..cbed141
--- /dev/null
+++ b/roles/postgresql/templates/postgresql-passwd.j2
@@ -0,0 +1,19 @@
+root:x:0:0:root:/root:/bin/bash
+daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
+bin:x:2:2:bin:/bin:/usr/sbin/nologin
+sys:x:3:3:sys:/dev:/usr/sbin/nologin
+sync:x:4:65534:sync:/bin:/bin/sync
+games:x:5:60:games:/usr/games:/usr/sbin/nologin
+man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
+lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
+mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
+news:x:9:9:news:/var/spool/news:/usr/sbin/nologin
+uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin
+proxy:x:13:13:proxy:/bin:/usr/sbin/nologin
+www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
+backup:x:34:34:backup:/var/backups:/usr/sbin/nologin
+list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin
+irc:x:39:39:ircd:/run/ircd:/usr/sbin/nologin
+_apt:x:42:65534::/nonexistent:/usr/sbin/nologin
+nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
+postgres:x:{{ postgresql_user_id }}:{{ postgresql_user_group_id }}::/var/lib/postgresql:/bin/bash
diff --git a/roles/postgresql/vars/main.yml b/roles/postgresql/vars/main.yml
new file mode 100644
index 0000000..ed8f50a
--- /dev/null
+++ b/roles/postgresql/vars/main.yml
@@ -0,0 +1,6 @@
+---
+postgresql_states:
+  - present
+  - absent
+postgresql_deployment_methods:
+  - docker