tftsr_ai/playbooks/02_infrastructure.yml

---
# playbooks/02_infrastructure.yml
# Install Docker and configure Ollama on ai_server

- name: "Infrastructure | Docker and Ollama setup on ai_server"
  hosts: ai_server
  become: true
  gather_facts: true
  tags:
    - infrastructure
  vars:
    vault_token_file: "{{ playbook_dir }}/../vault/.vault-token"
    vault_url: "http://{{ ai_server_ip }}:{{ vault_port }}"

  pre_tasks:
    - name: "Infrastructure | Install Python Docker SDK prerequisites"
      ansible.builtin.dnf:
        name:
          - python3-pip
          - python3-requests
          - numactl
        state: present
      tags: always

    - name: "Infrastructure | Install Python docker SDK via pip"
      ansible.builtin.pip:
        name: docker
        state: present
        executable: pip3
      tags: always

  tasks:
    # ── Docker installation ──────────────────────────────────────────
    - name: "Docker | Check if Docker CE repo is already configured"
      ansible.builtin.stat:
        path: /etc/yum.repos.d/docker-ce.repo
      register: docker_repo_file
      tags:
        - docker

    - name: "Docker | Add Docker CE repository"
      ansible.builtin.command:
        cmd: dnf config-manager --add-repo https://download.docker.com/linux/fedora/docker-ce.repo
      when: not docker_repo_file.stat.exists
      changed_when: true
      tags:
        - docker

    - name: "Docker | Install Docker CE packages"
      ansible.builtin.dnf:
        name:
          - docker-ce
          - docker-ce-cli
          - containerd.io
          - docker-compose-plugin
        state: present
      tags:
        - docker

    - name: "Docker | Add {{ ansible_user }} to docker group"
      ansible.builtin.user:
        name: "{{ ansible_user }}"
        groups: docker
        append: true
      tags:
        - docker

    - name: "Docker | Add ollama user to docker group"
      ansible.builtin.user:
        name: ollama
        groups: docker
        append: true
      tags:
        - docker

    - name: "Docker | Start and enable docker.service"
      ansible.builtin.systemd:
        name: docker
        state: started
        enabled: true
      tags:
        - docker

    # ── Ollama installation and configuration ────────────────────────
    - name: "Ollama | Check if ollama binary exists"
      ansible.builtin.stat:
        path: "{{ item }}"
      loop:
        - /usr/local/bin/ollama
        - /usr/bin/ollama
      register: ollama_binary_check
      tags:
        - ollama

    - name: "Ollama | Set ollama installed fact"
      ansible.builtin.set_fact:
        ollama_installed: "{{ ollama_binary_check.results | selectattr('stat.exists', 'equalto', true) | list | length > 0 }}"
      tags:
        - ollama

    - name: "Ollama | Install Ollama"
      ansible.builtin.shell:
        cmd: curl -fsSL https://ollama.ai/install.sh | sh
      when: not ollama_installed
      changed_when: true
      tags:
        - ollama

    - name: "Ollama | Retrieve OLLAMA_API_KEY from Vault"
      ansible.builtin.set_fact:
        ollama_api_key: "{{ lookup('community.hashi_vault.hashi_vault', vault_secret_prefix ~ '/ollama:api_key token=' ~ lookup('ansible.builtin.file', vault_token_file) ~ ' url=' ~ vault_url) }}"
      tags:
        - ollama

    - name: "Ollama | Create systemd override directory"
      ansible.builtin.file:
        path: /etc/systemd/system/ollama.service.d
        state: directory
        mode: "0755"
        owner: root
        group: root
      tags:
        - ollama

    - name: "Ollama | Template systemd override configuration"
      ansible.builtin.template:
        src: "{{ playbook_dir }}/../templates/ollama/override.conf.j2"
        dest: /etc/systemd/system/ollama.service.d/override.conf
        mode: "0644"
        owner: root
        group: root
      notify:
        - Reload systemd and restart ollama
      tags:
        - ollama

    - name: "Ollama | Ensure Ollama is running"
      ansible.builtin.systemd:
        name: ollama
        state: started
        enabled: true
      tags:
        - ollama

    - name: "Ollama | Wait for Ollama API to be ready"
      ansible.builtin.uri:
        url: "http://localhost:11434/api/tags"
        method: GET
        status_code: 200
        timeout: 10
      register: ollama_ready
      retries: 24
      delay: 5
      until: ollama_ready.status == 200
      tags:
        - ollama

    - name: "Ollama | Deploy ollama-node0 systemd unit"
      ansible.builtin.template:
        src: "{{ playbook_dir }}/../templates/ollama/ollama-node0.service.j2"
        dest: /etc/systemd/system/ollama-node0.service
        mode: "0644"
        owner: root
        group: root
      notify:
        - Reload systemd and start ollama-node0
      tags:
        - ollama

    - name: "Ollama | Enable and start ollama-node0"
      ansible.builtin.systemd:
        name: ollama-node0
        enabled: true
        state: started
        daemon_reload: true
      tags:
        - ollama

    - name: "Ollama | Wait for ollama-node0 API to be ready"
      ansible.builtin.uri:
        url: "http://localhost:{{ ollama_node0_port }}/api/tags"
        method: GET
        headers:
          Authorization: "Bearer {{ ollama_api_key }}"
        status_code: 200
        timeout: 10
      register: ollama_node0_ready
      retries: 24
      delay: 5
      until: ollama_node0_ready.status == 200
      tags:
        - ollama

    # ── OS-level kernel tuning for dedicated inference server ────────────────
    - name: "OS Tune | Apply sysctl settings for inference workload"
      ansible.posix.sysctl:
        name: "{{ item.name }}"
        value: "{{ item.value }}"
        sysctl_file: /etc/sysctl.d/99-ollama-perf.conf
        reload: true
        state: present
      loop:
        # Disable auto-NUMA migration — CPUAffinity pins Ollama to node 1/0
        # physical cores; NUMA balancing could migrate pages mid-inference.
        - { name: kernel.numa_balancing, value: "0" }
        # Near-zero swappiness: prevents model weights being paged out under
        # memory pressure (complements LimitMEMLOCK=infinity in the unit file).
        - { name: vm.swappiness, value: "1" }
        # Required for mlock to succeed without reservation failures.
        - { name: vm.overcommit_memory, value: "1" }
      tags:
        - os-tune

    - name: "OS Tune | Set Transparent Huge Pages to madvise (immediate)"
      ansible.builtin.shell:
        cmd: echo madvise > /sys/kernel/mm/transparent_hugepage/enabled
      changed_when: true
      tags:
        - os-tune

    - name: "OS Tune | Install THP madvise persistence service"
      ansible.builtin.copy:
        dest: /etc/systemd/system/thp-madvise.service
        mode: "0644"
        owner: root
        group: root
        content: |
          [Unit]
          Description=Set Transparent Huge Pages to madvise
          After=local-fs.target

          [Service]
          Type=oneshot
          ExecStart=/bin/sh -c 'echo madvise > /sys/kernel/mm/transparent_hugepage/enabled'
          RemainAfterExit=yes

          [Install]
          WantedBy=multi-user.target
      notify:
        - Reload systemd daemon
      tags:
        - os-tune

    - name: "OS Tune | Enable THP madvise persistence service"
      ansible.builtin.systemd:
        name: thp-madvise.service
        enabled: true
        daemon_reload: false
      tags:
        - os-tune

    - name: "OS Tune | Set CPU governor to performance (immediate)"
      ansible.builtin.shell:
        cmd: |
          for gov in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do
            [ -f "$gov" ] && echo performance > "$gov"
          done
      changed_when: true
      tags:
        - os-tune

    - name: "OS Tune | Install CPU performance governor persistence service"
      ansible.builtin.copy:
        dest: /etc/systemd/system/cpu-performance.service
        mode: "0644"
        owner: root
        group: root
        content: |
          [Unit]
          Description=Set CPU scaling governor to performance
          After=local-fs.target

          [Service]
          Type=oneshot
          ExecStart=/bin/sh -c 'for gov in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do [ -f "$gov" ] && echo performance > "$gov"; done'
          RemainAfterExit=yes

          [Install]
          WantedBy=multi-user.target
      notify:
        - Reload systemd daemon
      tags:
        - os-tune

    - name: "OS Tune | Enable CPU performance governor persistence service"
      ansible.builtin.systemd:
        name: cpu-performance.service
        enabled: true
        daemon_reload: false
      tags:
        - os-tune

  handlers:
    - name: Reload systemd and restart ollama
      ansible.builtin.systemd:
        name: ollama
        state: restarted
        daemon_reload: true

    - name: Reload systemd and start ollama-node0
      ansible.builtin.systemd:
        name: ollama-node0
        state: started
        daemon_reload: true

    - name: Reload systemd daemon
      ansible.builtin.systemd:
        daemon_reload: true