Add basic caddy role

roles/caddy/defaults/main.yml

@@ -0,0 +1,11 @@
+---
+# file: roles/caddy/defaults/main.yml
+
+# parent directory of vhost document roots
+caddy_root_prefix: /var/www
+
+# Email address to use for the ACME account managing the site's certificates.
+# Not sure what Caddy does if this doesn't exist.
+caddy_email: foo@example.com
+
+# vim: set ts=2 sw=2:

roles/caddy/handlers/main.yml

@@ -0,0 +1,10 @@
+---
+# file: roles/caddy/handlers/main.yml
+
+# I'm currently not sure when we need to restart versus reload
+- name: reload caddy
+  ansible.builtin.systemd:
+    name: caddy
+    state: reloaded
+
+# vim: set sw=2 ts=2:

roles/caddy/tasks/main.yml

@@ -0,0 +1,83 @@
+---
+# file: roles/caddy/tasks/main.yml
+#
+# Configure Caddy.
+
+- name: Check Caddy package signing key
+  ansible.builtin.stat:
+    path: /etc/apt/keyrings/caddy-stable-archive-keyring.key
+  register: caddy_signing_key_stat
+  tags:
+    - packages
+    - caddy
+
+# See: https://caddyserver.com/docs/install#debian-ubuntu-raspbian
+- name: Download Caddy package signing key
+  ansible.builtin.get_url:
+    url: https://dl.cloudsmith.io/public/caddy/stable/gpg.key
+    dest: /etc/apt/keyrings/caddy-stable-archive-keyring.key
+    owner: root
+    group: root
+    mode: 0644
+  register: download_caddy_signing_key
+  when: not caddy_signing_key_stat.stat.exists
+  tags:
+    - packages
+    - caddy
+
+- name: Add Caddy stable repo
+  ansible.builtin.apt_repository:
+    repo: 'deb [signed-by=/etc/apt/keyrings/caddy-stable-archive-keyring.key] https://dl.cloudsmith.io/public/caddy/stable/deb/debian any-version main'
+    filename: caddy-stable
+    state: present
+  register: add_caddy_apt_repository
+  tags:
+    - packages
+    - caddy
+
+- name: Update apt cache
+  ansible.builtin.apt: # noqa no-handler
+    update_cache: true
+  when:
+    (download_caddy_signing_key.status_code is defined and download_caddy_signing_key.status_code == 200) or
+    add_caddy_apt_repository is changed
+  tags:
+    - packages
+    - caddy
+
+- name: Install Caddy
+  ansible.builtin.apt:
+    name: caddy
+    state: present
+    install_recommends: false
+    cache_valid_time: 3600
+  tags:
+    - caddy
+    - packages
+
+- name: Create Caddyfile
+  ansible.builtin.template:
+    src: etc/caddy/Caddyfile.j2
+    dest: /etc/caddy/Caddyfile
+    mode: 0755
+    owner: root
+    group: root
+  notify:
+    - reload caddy
+  tags: caddy
+
+- name: Create Caddy conf.d directory
+  ansible.builtin.file:
+    path: /etc/caddy/conf.d
+    state: directory
+    mode: 0755
+    owner: root
+    group: root
+
+# TODO: the variable is still named nginx_vhosts
+- name: Configure Caddy virtual hosts
+  ansible.builtin.include_tasks: vhosts.yml
+  when: nginx_vhosts is defined
+  tags: caddy
+
+# vim: set sw=2 ts=2:

roles/caddy/tasks/vhosts.yml

@@ -0,0 +1,15 @@
+---
+
+- name: Configure vhosts
+  ansible.builtin.template:
+    src: etc/caddy/conf.d/vhost.j2
+    dest: /etc/caddy/conf.d/{{ item.domain_name }}
+    mode: 0644
+    owner: root
+    group: root
+  loop: "{{ nginx_vhosts }}"
+  notify:
+    - reload caddy
+  tags: caddy
+
+# vim: set ts=2 sw=2:

roles/caddy/templates/etc/caddy/Caddyfile.j2

@@ -0,0 +1,29 @@
+# Global options
+{
+    email {{ caddy_email }}
+}
+
+# Common security response headers
+(security-headers) {
+    header {
+        # disable Google FLoC tracking
+        Permissions-Policy interest-cohort=()
+
+        # enable HSTS
+        Strict-Transport-Security max-age=31536000
+
+        # disable clients from sniffing the media type
+        X-Content-Type-Options nosniff
+
+        # clickjacking protection: refuse to allow rendering this page
+        # in a frame, iframe, etc.
+        X-Frame-Options DENY
+
+        # keep referrer data off of HTTP connections
+        Referrer-Policy no-referrer-when-downgrade
+    }
+}
+
+# Import additional caddy config files in /etc/caddy/conf.d/
+# Note: these are imported in lexical sort order!
+import /etc/caddy/conf.d/*

roles/caddy/templates/etc/caddy/conf.d/vhost.j2

@@ -0,0 +1,17 @@
+{{ ansible_managed | comment }}
+
+{# helper variables and per-site defaults that we can't set in role defaults #}
+{% set domain_name    = item.domain_name %}
+{% set domain_aliases = item.domain_aliases | default("") %}
+{# assume optional features are off unless a vhost explicitly sets them #}
+{% set has_wordpress  = item.has_wordpress | default(false) %}
+{% set needs_php      = item.needs_php | default(false) %}
+{% set has_gitea      = item.has_gitea | default(false) %}
+
+{{ domain_name }} {
+    {% if has_gitea %}
+    reverse_proxy :3000
+    {% endif %}
+
+    import security-headers
+}

web.yml

@@ -7,7 +7,8 @@
   roles:
     - common
     - { role: mariadb, when: mariadb_databases is defined}
-    - nginx
+    - { role: nginx, when: webserver is defined and webserver == 'nginx' }
+    - { role: caddy, when: webserver is defined and webserver == 'caddy' }
     - php-fpm
     - munin
   vars_files: