impress/deploy/setup.yml

---
- name: Set up the environment for the impress app
  hosts: webserver
  become: yes
  become_user: root
  vars:
    email_address: "emi@matchu.dev" # TODO: Extract this to personal config?
    impress_hostname: impress.openneo.net
  tasks:
    - name: Create SSH folder for logged-in user
      become: no
      file:
        name: .ssh
        mode: "700"
        state: directory

    - name: Copy authorized SSH keys to logged-in user
      become: no
      copy:
        dest: ~/.ssh/authorized_keys
        src: files/authorized-ssh-keys.txt
        mode: "600"

    - name: Disable root SSH login
      lineinfile:
        dest: /etc/ssh/sshd_config
        regexp: ^#?PermitRootLogin
        line: PermitRootLogin no

    - name: Disable password-based SSH authentication
      lineinfile:
        dest: /etc/ssh/sshd_config
        regexp: ^#?PasswordAuthentication
        line: PasswordAuthentication no

    - name: Enable public-key SSH authentication
      lineinfile:
        dest: /etc/ssh/sshd_config
        regexp: ^#?PubkeyAuthentication
        line: PubkeyAuthentication yes

    - name: Update the apt cache
      apt:
        update_cache: yes

    - name: Install fail2ban firewall with default settings
      apt:
        name: fail2ban

    - name: Configure ufw firewall to allow SSH connections on port 22
      community.general.ufw:
        rule: allow
        port: "22"

    - name: Configure ufw firewall to allow HTTP connections on port 80
      community.general.ufw:
        rule: allow
        port: "80"

    - name: Configure ufw firewall to allow HTTPS connections on port 443
      community.general.ufw:
        rule: allow
        port: "443"

    - name: Enable ufw firewall with all other ports closed by default
      community.general.ufw:
        state: enabled
        policy: deny

    - name: Install unattended-upgrades
      apt:
        name: unattended-upgrades

    - name: Enable unattended-upgrades to auto-upgrade our system
      copy:
        content: |
          APT::Periodic::Update-Package-Lists "1";
          APT::Periodic::Unattended-Upgrade "1";          
        dest: /etc/apt/apt.conf.d/20auto-upgrades

    - name: Configure unattended-upgrades to auto-reboot our server when necessary
      lineinfile:
        regex: ^(//\s*)?Unattended-Upgrade::Automatic-Reboot ".*";$
        line: Unattended-Upgrade::Automatic-Reboot "true";
        dest: /etc/apt/apt.conf.d/50unattended-upgrades

    - name: Configure unattended-upgrades to delay necessary reboots to 3am
      lineinfile:
        regex: ^(//\s*)?Unattended-Upgrade::Automatic-Reboot-Time ".*";$
        line: Unattended-Upgrade::Automatic-Reboot-Time "03:00";
        dest: /etc/apt/apt.conf.d/50unattended-upgrades

    - name: Configure the system timezone to be US Pacific time
      community.general.timezone:
        name: America/Los_Angeles

    - name: Create "impress" user
      user:
        name: impress
        comment: Impress App
        home: /srv/impress
        create_home: false
        shell: /bin/bash

    - name: Create "impress-deployers" group
      group:
        name: impress-deployers

    - name: Add the current user to the "impress-deployers" group
      user:
        name: "{{ lookup('env', 'USER') }}"
        groups:
          - impress-deployers
        append: yes

    # We use this so the deploy playbook doesn't have to prompt for a root
    # password: this user just is trusted to act as "impress" in the future.
    - name: Enable the "impress-deployers" group to freely act as the "impress" user
      community.general.sudoers:
        name: impress-deployers-as-impress
        group: impress-deployers
        runas: impress
        commands: ALL
        nopassword: yes

    # Similarly, this enables us to manage the impress service in the deploy playbook
    # and in live debugging without a password.
    # NOTE: In the sudoers file, you need to specify the full path to the
    # command, to avoid tricks where you use PATH to get around the intent!
    - name: Enable the "impress-deployers" group to freely start and stop the impress service
      community.general.sudoers:
        name: impress-deployers-systemctl
        group: impress-deployers
        commands:
          - /bin/systemctl status impress
          - /bin/systemctl start impress
          - /bin/systemctl stop impress
          - /bin/systemctl restart impress
        nopassword: yes

    - name: Install ACL, to enable us to run commands as the "impress" user
      apt:
        name: acl

    - name: Install ruby-build
      git:
        repo: https://github.com/rbenv/ruby-build.git
        dest: /opt/ruby-build
        version: 4d4678bc1ed89aa6900c0ea0da23495445dbcf50

    - name: Check if Ruby 3.1.4 is already installed
      stat:
        path: /opt/ruby-3.1.4
      register: ruby_dir

    - name: Install Ruby 3.1.4
      command: "/opt/ruby-build/bin/ruby-build 3.1.4 /opt/ruby-3.1.4"
      when: not ruby_dir.stat.exists

    - name: Add Ruby 3.1.4 to the global PATH, for developer convenience
      lineinfile:
        dest: /etc/profile
        line: 'PATH="/opt/ruby-3.1.4/bin:$PATH" # Added by impress deploy setup script'

    - name: Install system dependencies for impress's Ruby gems
      apt:
        name:
          - libmysqlclient-dev
          - libyaml-dev

    - name: Create the app folder
      file:
        path: /srv/impress
        owner: impress
        group: impress
        mode: "755"
        state: directory

    - name: Add a convenient .bash_profile for when we log in as "impress"
      copy:
        owner: impress
        group: impress
        dest: /srv/impress/.bash_profile
        content: |
          set -a # Export all of the below
          RAILS_ENV=production
          EXECJS_RUNTIME=Disabled
          source /srv/impress/shared/production.env
          set +a          

    - name: Create the app's "versions" folder
      become_user: impress
      file:
        path: /srv/impress/versions
        state: directory

    - name: Create the app's "shared" folder
      become_user: impress
      file:
        path: /srv/impress/shared
        state: directory

    - name: Check for a current app version
      stat:
        path: /srv/impress/current
      register: current_app_version

    - name: Check whether we already have a placeholder app
      stat:
        path: /srv/impress/versions/initial-placeholder
      register: existing_placeholder_app
      when: not current_app_version.stat.exists

    - name: Create a placeholder app, to run until we deploy a real version
      become_user: impress
      copy:
        src: files/initial-placeholder
        dest: /srv/impress/versions
      when: |
        not current_app_version.stat.exists and
          not existing_placeholder_app.stat.exists        

    - name: Configure the placeholder app to run in deployment mode
      become_user: impress
      command:
        chdir: /srv/impress/versions/initial-placeholder
        cmd: /opt/ruby-3.1.4/bin/bundle config set --local deployment true
      when: not current_app_version.stat.exists

    - name: Install the placeholder app's dependencies
      become_user: impress
      command:
        chdir: /srv/impress/versions/initial-placeholder
        cmd: /opt/ruby-3.1.4/bin/bundle install
      when: not current_app_version.stat.exists

    - name: Set the placeholder app as the current version
      become_user: impress
      file:
        src: /srv/impress/versions/initial-placeholder
        dest: /srv/impress/current
        state: link
      when: not current_app_version.stat.exists

    # NOTE: This file is uploaded with stricter permissions, to help protect
    # the secrets inside. Most of the app is world-readable for convenience
    # for debugging and letting nginx serve static files, but keep this safer!
    - name: Upload the production.env file
      become_user: impress
      copy:
        dest: /srv/impress/shared/production.env
        src: files/production.env
        mode: "600"
      notify:
        - Reload systemctl
        - Restart impress

    - name: Create service file for impress
      copy:
        dest: /etc/systemd/system/impress.service
        content: |
          [Unit]
          Description=Dress to Impress webapp

          [Service]
          User=impress
          Restart=always
          WorkingDirectory=/srv/impress/current
          ExecStart=/opt/ruby-3.1.4/bin/bundle exec puma --port=3000
          Environment="RAILS_ENV=production"
          ; Set EXECJS_RUNTIME to save us from needing to install Node
          Environment="EXECJS_RUNTIME=Disabled"
          EnvironmentFile=/srv/impress/shared/production.env

          ; Some security directives, adapted from Akkoma's service file, they seem like sensible defaults!
          ; Use private /tmp and /var/tmp folders inside a new file system namespace, which are discarded after the process stops.
          PrivateTmp=true
          ; The /home, /root, and /run/user folders can not be accessed by this service anymore. If your Akkoma user has its home folder in one of the restricted places, or use one of these folders as its working directory, you have to set this to false.
          ProtectHome=true
          ; Mount /usr, /boot, and /etc as read-only for processes invoked by this service.
          ProtectSystem=full
          ; Sets up a new /dev mount for the process and only adds API pseudo devices like /dev/null, /dev/zero or /dev/random but not physical devices.
          PrivateDevices=true
          ; Ensures that the service process and all its children can never gain new privileges through execve().
          NoNewPrivileges=true
          ; Drops the sysadmin capability from the daemon.
          CapabilityBoundingSet=~CAP_SYS_ADMIN

          [Install]
          WantedBy=multi-user.target          
      notify:
        - Reload systemctl
        - Restart impress

    - name: Configure impress to run now, and automatically when the system starts
      systemd:
        name: impress
        state: started
        enabled: true

    - name: Install nginx
      apt:
        name: nginx

    - name: Install core snap
      community.general.snap:
        name: core

    - name: Install certbot as a snap
      community.general.snap:
        name: certbot
        classic: yes

    - name: Set up certbot
      command: "certbot certonly --nginx -n --agree-tos --email {{ email_address }} --domains {{ impress_hostname }}"

    - name: Add impress config file to nginx
      copy:
        content: |
          server {
            server_name {{ impress_hostname }};
            listen 80;
            if ($host = {{ impress_hostname }}) {
              return 301 https://$host$request_uri;
            }
          }

          server {
            server_name {{ impress_hostname }};
            listen 443 ssl;
            ssl_certificate /etc/letsencrypt/live/{{ impress_hostname }}/fullchain.pem;
            ssl_certificate_key /etc/letsencrypt/live/{{ impress_hostname }}/privkey.pem;
            include /etc/letsencrypt/options-ssl-nginx.conf;
            ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
            ssl_session_cache shared:SSL:10m; # https://superuser.com/q/1484466/14127

            root /srv/impress/current/public;

            # Try serving static files first. If not found, fall back to the app.
            try_files $uri/index.html $uri @app;

            location @app {
              proxy_pass http://127.0.0.1:3000;
              proxy_set_header X-Real-IP $remote_addr;
              proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
              proxy_set_header X-Forwarded-Proto https;
              proxy_set_header X-Forwarded-Server $host;
              proxy_set_header Host $http_host;
              proxy_redirect off;
            }
          }          
        dest: /etc/nginx/sites-available/impress.conf
      notify:
        - Restart nginx

    - name: Enable impress config file in nginx
      file:
        src: /etc/nginx/sites-available/impress.conf
        dest: /etc/nginx/sites-enabled/impress.conf
        state: link
      notify:
        - Restart nginx

  handlers:
    - name: Restart nginx
      systemd:
        name: nginx
        state: restarted

    - name: Reload systemctl
      command: systemctl daemon-reload

    - name: Restart impress
      systemd:
        name: impress
        state: restarted