Building

git clone https://github.com/texttechnologylab/Janus-Gateway.git
cd Janus-Gateway
docker compose build

The build compiles Janus and four dependencies from source and takes roughly 30 minutes. Layers are cached, so a failed build resumes rather than restarting.

If the build fails partway

Almost always a transient network error fetching one of the source dependencies. Re-run it.

Why from source

The distribution packages are too old for Janus 1.4, and - more importantly - the build must include usrsctp for data channels and --enable-post-processing for janus-pp-rec. Both are easy to omit and unpleasant to discover missing later.

Pinned versions

Build arguments in the Dockerfile:

Argument	Default
`JANUS_COMMIT`	`94408ffccbc1a7c39dac82d55e5dd475c807e770`	Janus 1.4.2
`JANUS_VERSION`	`1.4.2`	Label only
`LIBSRTP_VERSION`	`2.2.0`
`LIBWEBSOCKETS_BRANCH`	`v4.3-stable`

libnice and usrsctp build from their current default branches.

Changing the Janus version

docker compose build --build-arg JANUS_COMMIT=<sha> --build-arg JANUS_VERSION=<x.y.z>

For a permanent change, edit the Dockerfile defaults so the pin is recorded in version control - that is the point of pinning.

Verify what you built:

docker run --rm ghcr.io/texttechnologylab/janus-gateway:1.4.2 /opt/janus/bin/janus --version

libwebsockets flags

Two non-default flags exist to prevent known upstream issues.

Flag	Reason
`-DLWS_MAX_SMP=1`	meetecho/janus-gateway#732
`-DLWS_WITHOUT_EXTENSIONS=0`	meetecho/janus-gateway#2476

Publishing

.github/workflows/docker-publish.yml builds and pushes to GitHub Container Registry on a tag or a manual run. Tag releases to match the Janus version (1.4.2) so the image tag states what is inside it.