Add more stable reverse proxy updating

roles/whoami/defaults/main.yml

@@ -1,3 +1,5 @@
 ---
 
 whoami_version: latest
+
+whoami_upstream_file_dir: "{{ docker_stack_files_dir }}/whoami"

roles/whoami/handlers/main.yml

@@ -0,0 +1,32 @@
+## Register reverse proxy
+
+# figure out if upstream id exists
+- name: check whoami 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: "handle upstream"
+
+# upstream has to be created
+- name: add whoami upstream
+  community.docker.docker_container_exec:
+    container: "{{ caddy_container_id }}"
+    command: >
+      curl -X POST -H "Content-Type: application/json" -d @/stacks/{{ stack.name }}/upstream.json localhost:2019/config/apps/http/servers/srv0/routes/0/ 
+  become: yes
+  when: (result.stdout | from_json)['error'] is defined
+  listen: "handle upstream"
+
+# upstream already exists, patch it
+- name: patch whoami upstream
+  community.docker.docker_container_exec:
+    container: "{{ caddy_container_id }}"
+    command: >
+      curl -X PATCH -H "Content-Type: application/json" -d @/stacks/{{ stack.name }}/upstream.json localhost:2019/id/{{ stack.name }}_upstream/
+  become: yes
+  when: (result.stdout | from_json)['error'] is not defined
+  listen: "handle upstream"

roles/whoami/tasks/main.yml

@@ -1,35 +1,32 @@
 ---
 # install whoami container
+- name: Ensure upstream directory exists
+  ansible.builtin.file:
+    path: "{{ whoami_upstream_file_dir }}"
+    state: directory
+    mode: '0755'
+  become: true
+  tags: 
+    - fs
+
+- name: Update upstream template
+  ansible.builtin.template:
+    src: whoami_upstream.json.j2
+    dest: "{{ whoami_upstream_file_dir }}/upstream.json"
+  become: true
+  tags: 
+    - fs
+  notify: "handle upstream"
 
 - name: Deploy whoami to swarm
   community.general.docker_stack:
-    name: "{{ item.name }}"
+    name: "{{ stack.name }}"
     state: present
     prune: yes
     compose:
-      - "{{ item.compose }}"
-  with_items: "{{ whoami_stack }}"
-  when: whoami_stack is defined
+      - "{{ stack.compose }}"
+  when: stack is defined
   become: yes
   tags:
     - docker-swarm
-
-- name: Get caddy container id
-  ansible.builtin.command:
-    cmd: docker ps -q -f name=caddy_app
-  register: caddy_container_id
-  become: yes
-
-- name: Ensure caddy curl available
-  community.docker.docker_container_exec:
-    container: "{{ caddy_container_id.stdout }}"
-    command: >
-      apk add curl
-  become: yes
-
-- name: Add caddy reverse proxy
-  community.docker.docker_container_exec:
-    container: "{{ caddy_container_id.stdout }}"
-    command: >
-      curl localhost:2019/config/apps/http/servers/srv0/routes/0 -X POST -H "Content-Type: application/json" -d {{ whoami_upstream }}
-  become: yes
+  notify: "handle upstream"

roles/whoami/templates/whoami_upstream.json.j2

@@ -0,0 +1,13 @@
+{
+  "@id": "{{ stack.name }}_upstream",
+  "handle": [
+    {
+      "handler": "reverse_proxy",
+      "upstreams": [
+        {
+          "dial": "{{ stack.name }}_app:80"
+        }
+      ]
+    }
+  ]
+}

roles/whoami/vars/main.yml

@@ -1,9 +1,6 @@
 ---
 
-whoami_stack:
-  - name: whoami
-    compose: "{{ lookup('template', 'docker-stack.yml.j2') | from_yaml }}"
-
-whoami_upstream: >-
-  '{ "@id": "whoami_upstream", "handle": [{ "handler": "reverse_proxy", "upstreams": [{ "dial": "whoami_app:80"}]}] }'
+stack:
+  name: whoami
+  compose: "{{ lookup('template', 'docker-stack.yml.j2') | from_yaml }}"