D7.6 Πρακτικό παράδειγμα — Multi-container με Network & Volumes 🚀

# group_vars/all_managed.yml
app_name:    myapp
app_version: "{{ new_version | default('latest') }}"
app_env:     production
app_domain:  myapp.example.com

# Database
postgres_user: appuser
postgres_db:   appdb

# Resource limits
nginx_memory: "128m"
app_memory:   "512m"
db_memory:    "1g"
redis_memory: "256m"

# group_vars/vault.yml (encrypted with Ansible Vault)
vault_postgres_pass: "StrongP@ssw0rd!"
vault_redis_pass:    "RedisP@ssw0rd!"
vault_app_secret:    "SuperSecretKey!"

---
# docker-fullstack-networking.yml
# Multi-container stack με Networks & Volumes

- name: Docker Fullstack — Networks & Volumes
  hosts: "{{ target | default('all_managed') }}"
  become: true
  gather_facts: true

  vars:
    # ── Stack config ───────────────────────────
    stack_name:  "{{ app_name }}_{{ app_env }}"
    cert_dir:    /etc/nginx/certs
    config_dir:  /opt/{{ app_name }}/config
    backup_dir:  /opt/backups/docker

    # ── Images ────────────────────────────────
    images:
      nginx:    "nginx:1.25-alpine"
      app:      "{{ app_name }}:{{ app_version }}"
      postgres: "postgres:15-alpine"
      redis:    "redis:7.2-alpine"

  # ════════════════════════════════════════════
  # PHASE 1: PREREQUISITES
  # ════════════════════════════════════════════
  tasks:

    - name: "════ PHASE 1: Prerequisites ════"
      ansible.builtin.debug:
        msg: "Έλεγχος και προετοιμασία περιβάλλοντος..."

    # ── Directories ───────────────────────────
    - name: "📁 Δημιουργία directories"
      ansible.builtin.file:
        path:  "{{ item.path }}"
        state: directory
        owner: "{{ item.owner | default('root') }}"
        group: "{{ item.group | default('root') }}"
        mode:  "{{ item.mode | default('0755') }}"
      loop:
        - { path: "{{ cert_dir }}",   mode: '0700' }
        - { path: "{{ config_dir }}", mode: '0755' }
        - { path: "{{ backup_dir }}/{{ inventory_hostname }}" }

    # ── Nginx config ──────────────────────────
    - name: "⚙️ Nginx config"
      ansible.builtin.template:
        src:   templates/nginx-proxy.conf.j2
        dest:  "{{ config_dir }}/nginx.conf"
        mode:  '0644'

    # ── Pull images ───────────────────────────
    - name: "📦 Pull Docker images"
      community.docker.docker_image:
        name:   "{{ item.key }}"
        tag:    "{{ item.value | split(':') | last }}"
        source: pull
      loop:     "{{ images | dict2items }}"
      loop_control:
        label: "{{ item.value }}"
      async:  300
      poll:   10

  # ════════════════════════════════════════════
  # PHASE 2: NETWORKS
  # ════════════════════════════════════════════

    - name: "════ PHASE 2: Networks ════"
      ansible.builtin.debug:
        msg: "Δημιουργία Docker networks..."

    - name: "🌐 Frontend network"
      community.docker.docker_network:
        name:   "{{ stack_name }}_frontend"
        state:  present
        driver: bridge
        ipam_config:
          - subnet:  "10.200.1.0/24"
            gateway: "10.200.1.1"
        labels:
          stack:       "{{ stack_name }}"
          layer:       frontend
          managed-by:  ansible

    - name: "🌐 Backend network (internal)"
      community.docker.docker_network:
        name:     "{{ stack_name }}_backend"
        state:    present
        driver:   bridge
        internal: true    # ← ΔΕΝ έχει internet access!
        ipam_config:
          - subnet:  "10.200.2.0/24"
            gateway: "10.200.2.1"
        labels:
          stack:      "{{ stack_name }}"
          layer:      backend
          managed-by: ansible

  # ════════════════════════════════════════════
  # PHASE 3: VOLUMES
  # ════════════════════════════════════════════

    - name: "════ PHASE 3: Volumes ════"
      ansible.builtin.debug:
        msg: "Δημιουργία Docker volumes..."

    - name: "💾 Δημιουργία named volumes"
      community.docker.docker_volume:
        name:  "{{ item.name }}"
        state: present
        labels:
          stack:       "{{ stack_name }}"
          purpose:     "{{ item.purpose }}"
          backup:      "{{ item.backup | string }}"
          managed-by:  ansible
      loop:
        - { name: "{{ stack_name }}_postgres", purpose: database, backup: true  }
        - { name: "{{ stack_name }}_redis",    purpose: cache,    backup: false }
        - { name: "{{ stack_name }}_uploads",  purpose: media,    backup: true  }
      loop_control:
        label: "{{ item.name }}"

  # ════════════════════════════════════════════
  # PHASE 4: CONTAINERS
  # ════════════════════════════════════════════

    - name: "════ PHASE 4: Containers ════"
      ansible.builtin.debug:
        msg: "Deployment containers..."

    # ── PostgreSQL ────────────────────────────
    - name: "🐘 PostgreSQL container"
      community.docker.docker_container:
        name:           "{{ stack_name }}_postgres"
        image:          "{{ images.postgres }}"
        state:          started
        restart_policy: unless-stopped
        memory:         "{{ db_memory }}"
        networks:
          - name: "{{ stack_name }}_backend"    # ← backend only!
        volumes:
          - "{{ stack_name }}_postgres:/var/lib/postgresql/data:rw"
        env:
          POSTGRES_DB:       "{{ postgres_db }}"
          POSTGRES_USER:     "{{ postgres_user }}"
          POSTGRES_PASSWORD: "{{ vault_postgres_pass }}"
          POSTGRES_INITDB_ARGS: "--encoding=UTF8 --locale=C"
        no_log: true
        healthcheck:
          test:         ["CMD-SHELL", "pg_isready -U {{ postgres_user }}"]
          interval:     10s
          timeout:      5s
          retries:      5
          start_period: 30s
        labels:
          stack:      "{{ stack_name }}"
          service:    postgres
          managed-by: ansible

    # ── Redis ─────────────────────────────────
    - name: "📮 Redis container"
      community.docker.docker_container:
        name:           "{{ stack_name }}_redis"
        image:          "{{ images.redis }}"
        state:          started
        restart_policy: unless-stopped
        memory:         "{{ redis_memory }}"
        networks:
          - name: "{{ stack_name }}_backend"    # ← backend only!
        volumes:
          - "{{ stack_name }}_redis:/data:rw"
        command: >
          redis-server
          --requirepass {{ vault_redis_pass }}
          --maxmemory {{ redis_memory }}
          --maxmemory-policy allkeys-lru
          --save 60 1000
        no_log: true
        healthcheck:
          test:     ["CMD", "redis-cli", "ping"]
          interval: 10s
          timeout:  5s
          retries:  3
        labels:
          stack:      "{{ stack_name }}"
          service:    redis
          managed-by: ansible

    # ── Αναμονή για backends ──────────────────
    - name: "⏳ Αναμονή για PostgreSQL"
      community.docker.docker_container_info:
        name: "{{ stack_name }}_postgres"
      register: pg_info
      until: >
        pg_info.container.State.Health is defined and
        pg_info.container.State.Health.Status == 'healthy'
      retries: 12
      delay:   5

    # ── Application ───────────────────────────
    - name: "🚀 Application container"
      community.docker.docker_container:
        name:           "{{ stack_name }}_app"
        image:          "{{ images.app }}"
        state:          started
        restart_policy: unless-stopped
        memory:         "{{ app_memory }}"
        networks:
          - name: "{{ stack_name }}_frontend"   # ← frontend
          - name: "{{ stack_name }}_backend"    # ← backend (για db/redis)
        volumes:
          - "{{ stack_name }}_uploads:/app/uploads:rw"
          - "{{ config_dir }}/app.env:/app/.env:ro"
        env:
          NODE_ENV:     "{{ app_env }}"
          DATABASE_URL: >
            postgresql://{{ postgres_user }}:{{ vault_postgres_pass }}
            @{{ stack_name }}_postgres:5432/{{ postgres_db }}
          REDIS_URL:    "redis://:{{ vault_redis_pass }}@{{ stack_name }}_redis:6379"
          SECRET_KEY:   "{{ vault_app_secret }}"
          APP_VERSION:  "{{ app_version }}"
        no_log: true
        healthcheck:
          test:         ["CMD-SHELL", "wget -qO- http://localhost:3000/health || exit 1"]
          interval:     15s
          timeout:      10s
          retries:      5
          start_period: 30s
        labels:
          stack:      "{{ stack_name }}"
          service:    app
          version:    "{{ app_version }}"
          managed-by: ansible

    # ── Nginx Reverse Proxy ───────────────────
    - name: "🌐 Nginx container"
      community.docker.docker_container:
        name:           "{{ stack_name }}_nginx"
        image:          "{{ images.nginx }}"
        state:          started
        restart_policy: unless-stopped
        memory:         "{{ nginx_memory }}"
        ports:
          - "80:80"
          - "443:443"
        networks:
          - name: "{{ stack_name }}_frontend"   # ← frontend only!
        volumes:
          - "{{ config_dir }}/nginx.conf:/etc/nginx/nginx.conf:ro"
          - "{{ cert_dir }}:/etc/nginx/certs:ro"
          - "{{ stack_name }}_uploads:/app/uploads:ro"    # ← static files
        healthcheck:
          test:     ["CMD-SHELL", "wget -qO- http://localhost/ || exit 1"]
          interval: 15s
          timeout:  5s
          retries:  3
        labels:
          stack:      "{{ stack_name }}"
          service:    nginx
          managed-by: ansible

  # ════════════════════════════════════════════
  # PHASE 5: VERIFICATION
  # ════════════════════════════════════════════

    - name: "════ PHASE 5: Verification ════"
      ansible.builtin.debug:
        msg: "Επαλήθευση stack..."

    - name: "🔍 Έλεγχος όλων των containers"
      community.docker.docker_container_info:
        name: "{{ item }}"
      register: stack_info
      loop:
        - "{{ stack_name }}_postgres"
        - "{{ stack_name }}_redis"
        - "{{ stack_name }}_app"
        - "{{ stack_name }}_nginx"
      loop_control:
        label: "{{ item }}"

    - name: "🔍 HTTP endpoint check"
      ansible.builtin.uri:
        url:         "http://localhost/health"
        status_code: 200
      register:  http_check
      retries:   5
      delay:     5
      until:     http_check.status == 200

    - name: "📊 Stack Report"
      ansible.builtin.debug:
        msg:
          - "╔══════════════════════════════════════════════╗"
          - "║  ✅ DOCKER STACK DEPLOYED!                   ║"
          - "╠══════════════════════════════════════════════╣"
          - "║  Stack  : {{ stack_name }}"
          - "║  Version: {{ app_version }}"
          - "╠══════════════════════════════════════════════╣"
          - "║  Networks:"
          - "║    frontend: {{ stack_name }}_frontend"
          - "║    backend:  {{ stack_name }}_backend (internal)"
          - "╠══════════════════════════════════════════════╣"
          - "║  Volumes:"
          - "║    postgres: {{ stack_name }}_postgres"
          - "║    redis:    {{ stack_name }}_redis"
          - "║    uploads:  {{ stack_name }}_uploads"
          - "╠══════════════════════════════════════════════╣"
          - "║  Containers:"
          - "{% for item in stack_info.results %}\
             ║    {{ item.item | replace(stack_name + '_', '') }}: {{ item.container.State.Status }}\
             {% endfor %}"
          - "╠══════════════════════════════════════════════╣"
          - "║  HTTP: {{ '✅ OK' if not http_check.failed else '❌ FAILED' }}"
          - "║  URL:  http://{{ ansible_facts['default_ipv4']['address'] }}"
          - "╚══════════════════════════════════════════════╝"