Arma Reforger Dedicated Server — Docker via Git Tags

This repository uses a GitHub Actions CI pipeline that automatically builds and pushes an Arma Reforger dedicated server Docker image to the GitHub Container Registry (ghcr.io/gruppe-adler/ars-image) whenever a git tag is pushed. No manual workflow triggering is needed — just push a tag in the right format.

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Tag Format

Tags must follow this four-part format, matching the Arma Reforger version number exactly:

<major>.<minor>.<patch>.<build>.<branch>

Segment	Description	Example
major	Major version	1
minor	Minor version	6
patch	Patch number	0
build	Build number	119
branch	Release channel	stable or experimental

Examples

Git Tag	Tags produced	Steam branch
1.6.0.119.stable	ars-image:stable, ars-image:1.6.0.119	Stable (App ID 1874900)
1.7.0.24.experimental	ars-image:experimental, ars-image:1.7.0.24	Experimental (App ID 1890870)

Tip: Match the tag to the official Arma Reforger version number shown in-game or on the Arma Reforger news page so it's clear which game build the image contains.

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How It Works

1. The pipeline splits the tag on the last . to extract:
   • VERSION — everything before the last dot (e.g. 1.6.0.119)
   • BRANCH_NAME — the last segment (stable or experimental)
2. If BRANCH_NAME is experimental, Steam downloads from App ID 1890870 (the experimental branch); otherwise it uses 1874900 (stable).
3. Two tags are pushed to the GitHub Container Registry:
   • ghcr.io/gruppe-adler/ars-image:<branch> — floating tag, always points to the latest build on that channel
   • ghcr.io/gruppe-adler/ars-image:<version> — pinned tag for this exact game version

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Runtime User

The server runs as the unprivileged user ubuntu (1000:1000) with HOME=/home/ubuntu. The installation in /ars stays owned by root and is only read and executed; the server writes to the -profile and -addonDownloadDir directories and /tmp.

arsa-backend also runs as 1000:1000 and owns the mounted config, profile and mod directories. It starts the server containers with that user explicitly (ARSA_ARS_USER), with all capabilities dropped and no-new-privileges, so older tags of this image that default to root run unprivileged as well.

When running the image by hand, the mounted directories must be writable for 1000:1000.

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Creating a Release

Prerequisites

• Write access to this repository
• Git installed locally

Stable release

# Pull latest changes first
git checkout main
git pull

# Tag with the current stable Arma Reforger version
git tag 1.6.0.119.stable
git push --tags

Experimental release

git tag 1.7.0.24.experimental
git push --tags

The CI pipeline starts automatically. Monitor progress under the Actions tab in GitHub.

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Deleting a Tag

If you need to retag or redo a build:

# Delete locally
git tag -d 1.6.0.119.stable

# Delete on remote
git push -f --tags

Then recreate and push the tag as normal.

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Branch Channels

Branch name	Purpose	Steam App ID
stable (or anything else)	Stable production server builds	1874900
experimental	Experimental / beta server builds	1890870

Any branch name other than experimental is treated as a stable release.