Add BACKUP_INTERVAL_MS environment variable for the Docker daemon

.env.example

@@ -5,3 +5,8 @@ GITHUB_TOKEN=your_github_token_here
 # Comma-separated list of GitHub users/organizations to backup
 # Example: SCHEDULED_USERS=octocat,github,spring-projects
 SCHEDULED_USERS=octocat
+
+# Delay between scheduled backups, in milliseconds
+# Leave empty to use the default of 86400000 (24 hours)
+# Example: BACKUP_INTERVAL_MS=3600000 (1 hour)
+BACKUP_INTERVAL_MS=

CHANGELOG.md

@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+## [Unreleased]
+
+### Added
+
+- `BACKUP_INTERVAL_MS` environment variable for the Docker daemon image, mapped by `docker-entrypoint.sh` to `-Dbackup.scheduled.interval.ms`, so the backup interval can be configured from `.env`/`docker-compose.yml` without overriding the entrypoint
+
 ## [2.0.0-SNAPSHOT-8-8-2026] – 2026-08-08
 
 ### Changed

CONFIG.md

@@ -145,15 +145,15 @@ When the image built from the included `Dockerfile` is used, the container alway
 | Variable | Maps to | Default in the image | Description |
 |----------|---------|----------------------|-------------|
 | `SCHEDULED_USERS` | `backup.scheduled.users` | *(empty)* | Comma-separated list of GitHub users/organizations to back up automatically. Passed to the application only when non-empty. |
+| `BACKUP_INTERVAL_MS` | `backup.scheduled.interval.ms` | *(empty)* | Delay between scheduled backups, in milliseconds. Passed to the application only when non-empty; when empty, the default of `86400000` (24 hours) from `application-daemon.properties` applies. |
 | `BACKUP_DIRECTORY` | `backup.directory` | `/backups` | Backup directory inside the container. |
 | `GITHUB_TOKEN` | *(read directly by the application)* | *(empty)* | GitHub personal access token, as described above. |
 
-Of these, only `GITHUB_TOKEN` and `SCHEDULED_USERS` are wired through to a `.env` file by the included `docker-compose.yml` (see `.env.example`); that file pins `BACKUP_DIRECTORY` to `/backups` and mounts the host's `./backups` directory there so backups persist outside the container.
-
-`backup.scheduled.interval.ms` has no corresponding environment variable, so a container built from this image backs up every 24 hours unless the entrypoint is overridden.
+Of these, `GITHUB_TOKEN`, `SCHEDULED_USERS` and `BACKUP_INTERVAL_MS` are wired through to a `.env` file by the included `docker-compose.yml` (see `.env.example`); that file pins `BACKUP_DIRECTORY` to `/backups` and mounts the host's `./backups` directory there so backups persist outside the container.
 
 **Example `.env`:**
 ```
 GITHUB_TOKEN=ghp_yourTokenHere
 SCHEDULED_USERS=octocat,github
+BACKUP_INTERVAL_MS=3600000
 ```

Dockerfile

@@ -24,6 +24,7 @@ RUN mkdir -p /backups
 ENV BACKUP_DIRECTORY=/backups
 ENV GITHUB_TOKEN=""
 ENV SCHEDULED_USERS=""
+ENV BACKUP_INTERVAL_MS=""
 
 # Expose port 8080 for optional web mode.
 # The default image entrypoint runs in daemon mode, so this port is only used if the

docker-compose.yml

@@ -10,7 +10,12 @@ services:
       # Comma-separated list of GitHub users/organizations to backup
       # Example: SCHEDULED_USERS=octocat,github,spring-projects
       - SCHEDULED_USERS=${SCHEDULED_USERS:-}
-
+
+      # Delay between scheduled backups, in milliseconds
+      # Leave empty for the default of 86400000 (24 hours)
+      # Example: BACKUP_INTERVAL_MS=3600000
+      - BACKUP_INTERVAL_MS=${BACKUP_INTERVAL_MS:-}
+
       # Optional: Custom backup directory inside container
       - BACKUP_DIRECTORY=/backups
     volumes:

docker-entrypoint.sh

@@ -13,6 +13,11 @@ if [ -n "$SCHEDULED_USERS" ]; then
     set -- "$@" "-Dbackup.scheduled.users=${SCHEDULED_USERS}"
 fi
 
+# Set backup interval if provided (defaults to 86400000 = 24 hours in application-daemon.properties)
+if [ -n "$BACKUP_INTERVAL_MS" ]; then
+    set -- "$@" "-Dbackup.scheduled.interval.ms=${BACKUP_INTERVAL_MS}"
+fi
+
 # Execute the application
 set -- "$@" -jar gh-backup.jar
 exec "$@"