PocketBase Trail Redux

Automatically reduces the file size of GPX tracks stored in a Wanderer PocketBase instance. Runs on a schedule, backs up the originals, replaces them with simplified versions, and optionally leaves a comment on the trail. (used on https://wadezimmer.de )

Setup

1. Create your configuration

Copy the example config and fill in your values:

cp config.example.json config.json

2. Start the service

docker compose up -d

Docker Compose

The docker-compose.yml contains everything needed to build and run the service:

services:
  trail-reader:
    build: .
    environment:
      - CRON_SCHEDULE=0 3 * * *
    volumes:
      - ./config.json:/app/config.json:ro
      - ./backups:/app/backups
      - ./state.json:/app/state.json
    restart: unless-stopped

Environment variables

Variable	Default	Description
CRON_SCHEDULE	0 3 * * *	How often the service runs, in standard cron syntax. The default runs once a day at 03:00.

Volumes

Host path	Container path	Description
./config.json	/app/config.json	Your configuration file (mounted read-only).
./backups	/app/backups	Directory where original and simplified GPX files are stored before replacement.
./state.json	/app/state.json	Tracks which trails have been processed. Must exist on the host before starting (see step 2).

Configuration

Setting	Description
LokiUrl	URL of a Grafana Loki instance for log shipping. Leave empty to disable.
PocketBase.Url	URL of your PocketBase / Wanderer instance (e.g. http://localhost:8090).
PocketBase.AdminEmail	Email address of a PocketBase super user account.
PocketBase.AdminPassword	Password for that account.
MinDistanceMeters	Minimum distance in meters between GPS points, per trail category. Points closer together than this will be merged. Higher values = smaller files but less detail. Example: {"Biking": 10, "Walking": 5}
MinSizeKb	Trails with a GPX file smaller than this (in KB) are skipped entirely.
MinRequiredSizePercent	Only replace a GPX file if the simplified version is smaller than this percentage of the original. For example, 40 means the file must be reduced to at most 40% of its original size, otherwise it is kept as-is.
Comments.User	Name of a local user (List "activitypub_actor" with "isLocal=true") in your Wanderer instance that will be used as the comment author. Leave empty to disable comments.
Comments.Content	The HTML content of the comment that gets posted on a trail after its GPX file was replaced.

Backups

Before replacing any GPX file, the original is saved to the backups/ directory (organized by date). The simplified version is also stored there under a smaller/ subfolder, so you can always compare or restore. It is still recommened to do a Database backup before starting this program

Logs

Container logs are available via:

docker compose logs -f

If LokiUrl is configured, logs are also shipped to Grafana Loki.