Janus Gateway

A pinned, reproducible container build of the Janus WebRTC Server with layered configuration.

📖 Documentation

• Janus: 1.4.2 (commit 94408ff) · Base: Ubuntu 24.04

Why

Pinned	Janus and every source dependency are fixed to exact versions. Images that track master build a different gateway every time - untenable when you must state which software produced a dataset.
Layered config	Stock Janus configs ship inside the image. You mount only the files you change, instead of vendoring 40 KB of defaults into every project.
Complete	Data channels (usrsctp) and recording post-processing (janus-pp-rec) are compiled in. Both are easy to leave out and painful to discover missing.

Quick start

docker run -d --network host \
    -v "$PWD/conf.d:/etc/janus.d:ro" \
    ghcr.io/texttechnologylab/janus-gateway:1.4.2

curl -s http://localhost:8088/janus/info | head -c 200

With an empty conf.d, that runs stock Janus.

Host networking is not required but highly recommended. ICE must see the real interface to gather usable candidates. Bridge networking gives you a gateway that negotiates successfully and then carries no media.

Changing configuration

The image ships Janus's stock configs. Anything you place in /etc/janus.d is copied over the matching default at startup, so you carry only what you change.

# 1. extract the default
docker run --rm ghcr.io/texttechnologylab/janus-gateway:1.4.2 \
    cat /opt/janus/etc/janus/janus.jcfg > conf.d/janus.jcfg

# 2. edit it, then restart
docker compose restart janus
docker compose logs janus | grep "applied override"

An override replaces a whole file - it does not merge. Janus config files have no include mechanism, so always start from the shipped default rather than writing a fragment.

Full reference, including every setting that usually needs changing: Configuration.

Building

docker compose build      # ~30 min, compiles from source
./test-entrypoint.sh      # config-layering self-check

See Building.

Used by

InterView - a VR interview platform - consumes this image and supplies two override files.

Licence

Packaging in this repository is AGPL-3.0 (LICENSE). Janus itself is GPL-3.0 and is compiled from upstream source during the image build.