Download the XMQ MQTT server

The free XMQ MQTT server is distributed as binary packages for Linux (.deb and .rpm), FreeBSD (pkg) and Windows, and as a Docker image. Pick the XMQ version and the operating system; each release also lists the SPTK class library it was built with, in source code and binary packages.

Source code: XMQ is developed in the open on GitHub - clone it, read it, or build it yourself; every release is tagged there under its version number. Found a problem? Report it on GitHub.

There is no XMQ package for this selection.

Run it in Docker

The same release is published as a Docker image, alexeyparshin/xmq. The image installs the .deb from this page rather than building from source, so a container holds exactly the binaries listed above. Tags are the version number and latest; the image is amd64, 36 MB to download.

docker run --rm -p 1883:1883 alexeyparshin/xmq

The broker takes clients with no credentials out of the box, so nothing has to be configured before the first publish:

mosquitto_pub -h localhost -t test/hello -m 'first message'

That default suits trying the broker out and nothing else. Add -e XMQ_ALLOW_ANONYMOUS=false before the container is reachable from a network you do not control, and create accounts in the configuration interface on https://localhost:18883 — published with -p 18883:18883, which opens once admin has a password. Set it once and restart; with /etc/xmq on a volume it stays set:

docker exec -it xmq xmq_server --set-password admin
docker restart xmq

MQTT over TLS is on 8883, with a self-signed certificate the container generates on first start.

The configuration, the accounts and the certificate live in /etc/xmq. Mount it, or every restart is a fresh install:

docker run -d --name xmq -p 1883:1883 -p 8883:8883 -p 18883:18883 -v xmq-config:/etc/xmq --ulimit nofile=1048576:1048576 alexeyparshin/xmq

The descriptor limit belongs there too: Docker gives a container 1024 open files, which caps the broker at about a thousand connections. Sessions, queued messages and retained messages are kept in Redis when XMQ_PERSISTENCE=true is set; the image page carries a compose file that starts the broker and Redis together, along with the full list of settings.