Experiment with PDF generation

Signed-off-by: David Young <davidy@funkypenguin.co.nz>

docs/recipes/gollum.md

@@ -0,0 +1,109 @@
+---
+title: Run Gollum in Docker
+---
+
+# Gollum
+
+Gollum is a simple wiki system built on top of Git. A Gollum Wiki is simply a git repository (_either bare or regular_) of a specific nature:
+
+* A Gollum repository's contents are human-editable, unless the repository is bare.
+* Pages are unique text files which may be organized into directories any way you choose.
+* Other content can also be included, for example images, PDFs and headers/footers for your pages.
+
+Gollum pages:
+
+* May be written in a variety of markups.
+* Can be edited with your favourite system editor or IDE (_changes will be visible after committing_) or with the built-in web interface.
+* Can be displayed in all versions (_commits_).
+
+![Gollum Screenshot](../images/gollum.png){ loading=lazy }
+
+As you'll note in the (_real world_) screenshot above, my requirements for a personal wiki are:
+
+* Portable across my devices
+* Supports images
+* Full-text search
+* Supports inter-note links
+* Revision control
+
+Gollum meets all these requirements, and as an added bonus, is extremely fast and lightweight.
+
+!!! note
+    Since Gollum itself offers no user authentication, this design secures gollum behind [traefik-forward-auth](/docker-swarm/traefik-forward-auth/), so that in order to gain access to the Gollum UI at all, authentication must have already occurred.
+
+--8<-- "recipe-standard-ingredients.md"
+
+## Preparation
+
+### Setup data locations
+
+We'll need an empty git repository in /var/data/gollum for our data:
+
+```bash
+
+mkdir /var/data/gollum
+cd /var/data/gollum
+git init
+
+```
+
+### Setup Docker Swarm
+
+Create a docker swarm config file in docker-compose syntax (v3), something like this:
+
+--8<-- "premix-cta.md"
+
+```yaml
+version: '3'
+
+services:
+  app:
+    image: dakue/gollum
+    volumes:
+     - /var/data/gollum:/gollum
+    networks:
+      - internal
+      - traefik_public
+    deploy:
+      labels:
+        # traefik common
+        - traefik.enable=true
+        - traefik.docker.network=traefik_public
+
+        # traefikv1
+        - traefik.frontend.rule=Host:gollum.example.com
+        - traefik.port=4567     
+
+        # traefikv2
+        - "traefik.http.routers.gollum.rule=Host(`gollum.example.com`)"
+        - "traefik.http.services.gollum.loadbalancer.server.port=4567"
+        - "traefik.enable=true"
+
+        # Remove if you wish to access the URL directly
+        - "traefik.http.routers.wekan.middlewares=forward-auth@file"
+    command: |
+      --allow-uploads
+      --emoji
+      --user-icons gravatar
+
+networks:
+  traefik_public:
+    external: true
+  internal:
+    driver: overlay
+    ipam:
+      config:
+        - subnet: 172.16.9.0/24
+```
+
+--8<-- "reference-networks.md"
+
+## Serving
+
+### Launch Gollum stack
+
+Launch the Gollum stack by running ```docker stack deploy gollum -c <path-to-docker-compose.yml>```
+
+[^1]: In the current implementation, Gollum is a "single user" tool only. The contents of the wiki are saved as markdown files under /var/data/gollum, and all the git commits are currently "Anonymous"
+
+--8<-- "recipe-footer.md"