feat(nextcloud): enable custom Alpine-based Whiteboard image with Chromium & ffmpeg support

- Added role tasks to deploy templated Dockerfile for Whiteboard service
- Configured build context and custom image name (nextcloud_whiteboard_custom)
- Increased PID limits and shm_size for stable recording
- Adjusted user ID variable naming consistency
- Integrated path_join for service directory variables
- Fixed build permissions (install as root, revert to nobody)

Reference: ChatGPT conversation https://chatgpt.com/share/68f771c6-0e98-800f-99ca-9e367f4cd0c2

roles/web-app-nextcloud/templates/Dockerfiles/Whiteboard.j2

@@ -0,0 +1,27 @@
+FROM {{ NEXTCLOUD_WHITEBOARD_IMAGE }}:{{ NEXTCLOUD_WHITEBOARD_VERSION }}
+
+# Temporarily switch to root so we can install packages
+USER 0
+
+# Install Chromium, ffmpeg, fonts, and runtime libraries for headless operation on Alpine
+RUN apk add --no-cache \
+      chromium \
+      ffmpeg \
+      nss \
+      freetype \
+      harfbuzz \
+      ttf-dejavu \
+      ttf-liberation \
+      udev \
+      ca-certificates \
+    && update-ca-certificates
+
+# Ensure a consistent Chromium binary path
+RUN if [ -x /usr/bin/chromium-browser ]; then ln -sf /usr/bin/chromium-browser /usr/bin/chromium; fi
+
+# Environment variables used by Puppeteer
+ENV PUPPETEER_EXECUTABLE_PATH=/usr/bin/chromium \
+    PUPPETEER_SKIP_DOWNLOAD=true
+
+# Switch back to the original non-root user (nobody)
+USER 65534

roles/web-app-nextcloud/templates/docker-compose.yml.j2

@@ -67,8 +67,12 @@
   {{ service_name }}:
 {% set container_port = NEXTCLOUD_WHITEBOARD_PORT_INTERNAL %}
 {% include 'roles/docker-container/templates/base.yml.j2' %}
+    build:
+      context: .
+      dockerfile: {{ NEXTCLOUD_WHITEBOARD_SERVICE_DOCKERFILE }}
+    pull_policy: never
 {% include 'roles/docker-container/templates/healthcheck/nc.yml.j2' %}
-    image: "{{ NEXTCLOUD_WHITEBOARD_IMAGE }}:{{ NEXTCLOUD_WHITEBOARD_VERSION }}"
+    image: "{{ NEXTCLOUD_WHITEBOARD_CUSTOM_IMAGE }}"
     container_name: {{ NEXTCLOUD_WHITEBOARD_CONTAINER }}
     volumes:
       - whiteboard_tmp:/tmp
@@ -76,6 +80,7 @@
 
     expose:
       - "{{ container_port }}"
+    shm_size: 1g
     networks:
       default:
         ipv4_address: 192.168.102.71

roles/web-app-nextcloud/templates/env.j2

@@ -65,6 +65,4 @@ CHROMIUM_FLAGS=--headless=new --no-sandbox --disable-gpu --disable-dev-shm-usage
 # Falls das Image Chromium mitbringt – Pfad meistens /usr/bin/chromium oder /usr/bin/chromium-browser:
 PUPPETEER_EXECUTABLE_PATH=/usr/bin/chromium
 PUPPETEER_SKIP_DOWNLOAD=true
-# Deactivated @todo implement
-WHITEBOARD_ENABLE_RECORDING=false
 {% endif %}