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/handlers/main.yml

@@ -0,0 +1,53 @@
+## Register reverse proxy
+- name: Ensure upstream directory exists
+  ansible.builtin.file:
+    path: "{{ nextcloud_upstream_file_dir }}"
+    state: directory
+    mode: '0755'
+  become: yes
+  listen: "update nextcloud upstream"
+
+- name: Update upstream template
+  ansible.builtin.template:
+    src: upstream.json.j2
+    dest: "{{ nextcloud_upstream_file_dir }}/upstream.json"
+  become: yes
+  listen: "update nextcloud upstream"
+
+# figure out if upstream id exists
+- name: check {{ stack_name }} upstream
+  community.docker.docker_container_exec:
+    container: "{{ caddy_container_id }}"
+    command: >
+      curl localhost:2019/id/{{ stack_name }}_upstream/
+  changed_when: False
+  register: result
+  become: yes
+  listen: "update nextcloud upstream"
+
+# upstream already exists, patch it
+- name: remove old {{ stack_name }} upstream
+  community.docker.docker_container_exec:
+    container: "{{ caddy_container_id }}"
+    command: >
+      curl -X DELETE localhost:2019/id/{{ stack_name }}_upstream/
+  become: yes
+  when: (result.stdout | from_json)['error'] is not defined
+  listen: "update nextcloud upstream"
+
+# upstream has to be created
+- name: add {{ stack_name }} upstream
+  community.docker.docker_container_exec:
+    container: "{{ caddy_container_id }}"
+    command: >
+      curl -X POST -H "Content-Type: application/json" -d @{{ nextcloud_upstream_file_dir }}/upstream.json localhost:2019/config/apps/http/servers/{{ (nextcloud_use_https == True) | ternary(caddy_https_server_name, caddy_http_server_name) }}/routes/0/ 
+  become: yes
+  listen: "update nextcloud upstream"
+
+- name: Ensure upstream directory is gone again
+  ansible.builtin.file:
+    path: "{{ nextcloud_upstream_file_dir }}"
+    state: absent
+  become: yes
+  listen: "update nextcloud upstream"
+