debian.ansible.docker/docker.yml

---

- name: docker
  hosts: all
  tasks:

### Docker ###

    - name: Create docker Group
      ansible.builtin.group:
        name: docker
        state: present
        gid: 1003

    - name: Create docker User
      ansible.builtin.user:
        name: docker
        comment: docker User
        uid: 1003
        group: docker

    - name: Hide docker user from login screen
      blockinfile:
        path: /var/lib/AccountsService/users/docker
        mode: "0444"
        owner: root
        group: root
        create: yes
        block: |
          [User]
          SystemAccount=true          
        backup: no

    - name: Create docker dir
      ansible.builtin.file:
        path: /home/docker
        owner: docker
        group: docker
        state: directory
        mode: '0750'

    - name: Create docker-data dir
      ansible.builtin.file:
        path: /home/docker/var-lib-docker
        owner: root
        group: root
        state: directory
        mode: '0710'

    - name: Create dir for container defaults
      ansible.builtin.file:
        path: /home/docker/_defaults
        owner: root
        group: docker
        state: directory
        mode: '0750'

    - name: Create /var/lib/docker -> /home/docker/var-lib-docker symlink
      ansible.builtin.file:
        src: /home/docker/var-lib-docker
        dest: /var/lib/docker
        owner: root
        group: root
        state: link

    - name: Remove packages for docker from default repo
      apt:
        name:
          - docker.io
          - docker-compose
          - containerd
          - runc
        state: absent
        update_cache: no
        install_recommends: no

    - name: Add signing key
      ansible.builtin.shell: curl -fsSL https://download.docker.com/linux/{{ ansible_distribution | lower }}/gpg | gpg --output  "/usr/share/keyrings/gpg-pub-docker.gpg" --dearmor
      args:
        creates: /usr/share/keyrings/gpg-pub-docker.gpg

    #- name: Add signing key
    #  ansible.builtin.apt_key:
    #    url: "https://download.docker.com/linux/{{ ansible_distribution | lower }}/gpg"
    #    state: present

    - name: Remove old repository from sources if exists
      ansible.builtin.apt_repository:
        repo: "deb https://download.docker.com/linux/{{ ansible_distribution | lower }} {{ ansible_distribution_release }} stable"
        state: absent
        filename: docker       

    - name: Add repository into list
      ansible.builtin.apt_repository:
        repo: "deb [arch=amd64 signed-by=/usr/share/keyrings/gpg-pub-docker.gpg] https://download.docker.com/linux/{{ ansible_distribution | lower }} {{ ansible_distribution_release }} stable"
        state: present
        filename: docker

    - name: Packages for docker
      apt:
        name:
          - docker-ce
          - docker-ce-cli 
          - containerd.io 
          - docker-buildx-plugin 
          - docker-compose-plugin
          - bridge-utils
          - apache2-utils
          - python3-docker
        update_cache: yes
        install_recommends: no
    
    # https://github.com/nextcloud/docker/issues/1103
    - name: writing daemon.json (ipv6 settings) 
      copy:
        dest: "/etc/docker/daemon.json"
        content: |
          {
            "ipv6": true,
            "fixed-cidr-v6": "fdab::/64",
            "experimental": true, 
            "ip6tables": true
          }

    - name: mariadb env defaults
      blockinfile:
        path: /home/docker/_defaults/mariadb/mariadb.env
        mode: "0444"
        owner: root
        group: root
        create: yes
        block: |
          MARIADB_RANDOM_ROOT_PASSWORD=1
          MARIADB_AUTO_UPGRADE=1
          MARIADB_INITDB_SKIP_TZINFO=1
          # from here: save memory https://techroads.org/reducing-memory-use-on-my-mariadb-mysql-wordpress-docker-stack/
          MARIADB_KEY_BUFFER_SIZE=1M
          MARIADB_MYISAMCHK_KEY_BUFFER_SIZE=1M
          MARIADB_INNODB_BUFFER_POOL_SIZE=10M
          MARIADB_INNODB_LOG_BUFFER_SIZE=512K
          MARIADB_MYISAM_SORT_BUFFER_SIZE=64K
          MARIADB_MYISAMCHK_SORT_BUFFER_SIZE=64K
          MARIADB_READ_BUFFER_SIZE=8K
          MARIADB_READ_RND_BUFFER_SIZE=8K
          MARIADB_SORT_BUFFER_SIZE=64K
        backup: yes

    - name: mariadb server config defaults
      blockinfile:
        path: /home/docker/_defaults/mariadb/99-server.cnf
        mode: "0444"
        owner: root
        group: root
        create: yes
        block: |
          [mariadbd]
          max_connections=10
          query_cache_size=512K
          thread_cache_size=0
          sort_buffer_size=64K
          bulk_insert_buffer_size=0
          tmp_table_size=1K
          max_heap_table_size=16K
          key_buffer_size=1M
          read_buffer_size=8K
          read_rnd_buffer_size=8K
          #innodb_buffer_pool_size=10K
          #innodb_log_buffer_size=512K
        backup: yes

    - name: docker-compose command/alias for backward compatibility - now docker compose
      blockinfile:
        path: /usr/local/sbin/docker-compose
        mode: "0755"
        owner: root
        group: root
        create: yes
        marker: "# {mark} ANSIBLE MANAGED BLOCK"
        block: |
          docker compose $@          
        backup: yes
        validate: /bin/bash -n %s 

    - name: /usr/local/sbin/docker-compose shebang
      lineinfile:
        path: /usr/local/sbin/docker-compose
        insertbefore: BOF
        line: "#!/bin/bash -e"