Add basic nextcloud deployment

Uses php-fpm image and is served through a simple caddy server.
Automatically deploys by default and can be automatically deployed with
smtp e-mail sending and s3 primary object storage optionally if desired.

Utilizes some necessary hackery for container ordering and startup so
startup is relatively slow (takes around 2-5 minutes at least) but once
running should be stable and uninterrupted.

Implements health-checks for all involved containers.

Switch apache for php-fpm image

roles/nextcloud/tasks/main.yml

@@ -0,0 +1,39 @@
+---
+## install container
+- name: Check upstream status
+  community.docker.docker_container_exec:
+    container: "{{ caddy_container_id }}"
+    command: >
+      curl localhost:2019/id/{{ stack_name }}_upstream/
+  register: result
+  changed_when: (result.stdout | from_json) != (lookup('template', 'upstream.json.j2') | from_yaml)
+  become: yes
+  notify: "update nextcloud upstream"
+
+- name: Ensure target directory exists
+  ansible.builtin.file:
+    path: "{{ nextcloud_upstream_file_dir }}"
+    state: directory
+    mode: '0755'
+  become: yes
+  notify: "update nextcloud upstream"
+
+- name: Move webserver Caddyfile to target dir
+  ansible.builtin.copy:
+    src: "Caddyfile"
+    dest: "{{ nextcloud_upstream_file_dir }}/Caddyfile"
+  become: yes
+  notify: "update nextcloud upstream"
+
+- name: Deploy to swarm
+  community.general.docker_stack:
+    name: "{{ stack_name }}"
+    state: present
+    prune: yes
+    compose:
+      - "{{ stack_compose }}"
+  become: yes
+  tags:
+    - docker-swarm
+  notify: "update nextcloud upstream"
+