container: support bind mounted db data directory and mysql config

roles/container/defaults/main.yml

@@ -2,5 +2,6 @@
 
 docker_host_user: false
 docker_volume_type: named
+docker_mariadb_config: {}
 
 timezone: Etc/UTC

roles/container/meta/argument_specs.yml

@@ -37,6 +37,19 @@ argument_specs:
         description: "database_passwords[docker_service] is a string with the password used for communication between the service and database. Required if docker_database is postgres or mariadb"
         type: dict
         required: false
+      docker_mariadb_config:
+        description: |
+          A dict specifying config for mariadb. For example
+          mysqld:
+            innodb_buffer_pool_size: '4G'
+            aria_pagecache_buffer_size': '4G'
+          would set
+          [mysqld]
+          innodb_buffer_pool_size = 4G
+          aria_pagecache_buffer_size = 4G
+        type: dict
+        required: false
+        default: {}
       docker_additional_services:
         description: "List of additional services to configure (in separate containers). These will be accessible with hostname <docker_service_name>[_suffix]_<additional_service>"
         type: list

roles/container/tasks/database.yml

@@ -28,6 +28,39 @@
     db_container_data: /data/db
   when: docker_database == 'mongo'
 
+- name: Reset db container mount definition var
+  set_fact:
+    db_container_mount_definition: []
+
+- name: Set up database container data bind mount
+  when: docker_volume_type == 'bind'
+  block:
+    - name: Create db data bind mount directory for {{ docker_service_name }}
+      file:
+        path: "{{ docker_mounts_dir }}/db"
+        state: directory
+
+    - name: Set db_container_mount_definition for db data bind mount
+      set_fact:
+        db_container_mount_definition: "{{ db_container_mount_definition + [{'source': docker_mounts_dir + '/db', 'target': db_container_data, 'type': 'bind'}] }}"
+
+- name: Set up database container config bind mount
+  when: db_config_mounts_needed
+  block:
+    - name: Put mariadb config in place
+      template:
+        src: mariadb.cnf.j2
+        dest: "{{ docker_mounts_dir }}/mariadb.cnf"
+
+    - name: Set db_container_mount_definition for db config bind mount
+      set_fact:
+        db_container_mount_definition: "{{ db_container_mount_definition + [{'source': docker_mounts_dir + '/mariadb.cnf', 'target': '/etc/mysql/conf.d/custom.cnf', 'type': 'bind', 'read_only': true}] }}"
+
+- name: Set db_container_mount_definition for db data named volume
+  set_fact:
+    db_container_mount_definition: "{{ db_container_mount_definition + [{'source': docker_service_name + '_db', 'target': db_container_data, 'type': 'volume'}] }}"
+  when: docker_volume_type == 'named'
+
 - name: Set db published ports var
   set_fact:
     db_published_ports: ["127.0.0.1:{{ ports[docker_service_name].db }}:{{ db_image_port }}"]
@@ -41,8 +74,6 @@
     env: "{{ db_container_env | default(omit) }}"
     published_ports: "{{ db_published_ports | default(omit) }}"
     restart_policy: always
-    mounts:
-      - source: "{{ docker_service_name + '_db' }}"
-        target: "{{ db_container_data }}"
+    mounts: "{{ db_container_mount_definition }}"
     networks: "{{ container_networks | default(omit) }}"
     log_driver: local

roles/container/tasks/init.yml

@@ -13,14 +13,15 @@
     template_mounts_needed: "{{ docker_mounts | selectattr('template', 'defined') | list | length > 0 }}"
     volumes_needed: "{{ docker_mounts | selectattr('name', 'defined') | list | length > 0 }}"
     dockerfile_needed: "{{ dockerfile is defined and dockerfile | length > 0 }}"
+    db_config_mounts_needed: "{{ docker_mariadb_config | length > 0 }}"
 - name: Set more assistive variables
   set_fact:
     bind_volumes_needed: "{{ volumes_needed and docker_volume_type == 'bind' }}"
     named_volumes_needed: "{{ volumes_needed and docker_volume_type == 'named' }}"
 - name: Set even more assistive variables
   set_fact:
-    create_opt_directory: "{{ dockerfile_needed or docker_host_user or bind_volumes_needed or template_mounts_needed }}"
-    create_mounts_directory: "{{ bind_volumes_needed or template_mounts_needed }}"
+    create_opt_directory: "{{ dockerfile_needed or docker_host_user or bind_volumes_needed or template_mounts_needed or db_config_mounts_needed }}"
+    create_mounts_directory: "{{ bind_volumes_needed or template_mounts_needed or db_config_mounts_needed }}"
 
 - name: Set docker service full name
   set_fact:

roles/container/tasks/main.yml

@@ -24,10 +24,6 @@
   include_tasks: proxy.yml
   when: reverse_proxy_type != 'none'
 
-- name: Database container
-  include_tasks: database.yml
-  when: docker_database != 'none'
-
 - name: Additional services
   when: docker_additional_services is defined
   block:
@@ -74,6 +70,25 @@
     container_workdir: /opt/{{ docker_service }}
   when: docker_service_suffix is not defined
 
+- name: Create mounts directory
+  when: create_mounts_directory
+  block:
+    - name: Set docker_mounts_dir
+      set_fact:
+        docker_mounts_dir: "{{ container_workdir }}/mounts"
+
+    - name: Create directory {{ docker_mounts_dir }}
+      file:
+        path: "{{ docker_mounts_dir }}"
+        state: directory
+        owner: "{{ user.uid | default(omit) }}"
+        group: "{{ user.group | default(omit) }}"
+        mode: 0700
+
+- name: Database container
+  include_tasks: database.yml
+  when: docker_database != 'none'
+
 - name: Container volumes
   import_tasks: volumes.yml
 

roles/container/tasks/volumes.yml

@@ -3,18 +3,7 @@
 - name: Create directories and put files in them
   when: create_mounts_directory
   block:
-    - name: Set docker_mounts_dir
-      set_fact:
-        docker_mounts_dir: "{{ container_workdir }}/mounts"
- 
-    - name: Create directory {{ docker_mounts_dir }}
-      file:
-        path: "{{ docker_mounts_dir }}"
-        state: directory
-        owner: "{{ user.uid | default(omit) }}"
-        group: "{{ user.group | default(omit) }}"
-        mode: 0700
-    - name: Define mounts directory owner
+    - name: Define mount directory owner
       set_fact:
         mount_owner: "{{ user.uid if docker_host_user else image_user | default('') }}"
         mount_group: "{{ user.group if docker_host_user else '' }}"

roles/container/templates/mariadb.cnf.j2

@@ -0,0 +1,8 @@
+# {{ ansible_managed }}
+
+{% for section in docker_mariadb_config | dict2items %}
+[{{ section.key }}]
+{% for item in section.value | dict2items %}
+{{ item.key }} = {{ item.value }}
+{% endfor %}
+{% endfor %}