v2: Docker host network mode as default

bt90 · June 20, 2025, 8:34am

This is more of a documentation thing if anything and not strictly tied to v2. But people will have a closer look at their deployments with v2 and I hope we can guide some of them towards a better setup.

We already have a documentation section that covers the host networking mode and how it improves discovery:

github.com/syncthing/syncthing

README-Docker.md

main

# Docker Container for Syncthing

Use the Dockerfile in this repo, or pull the `syncthing/syncthing` image
from Docker Hub.

Use the `/var/syncthing` volume to have the synchronized files available on the
host. You can add more folders and map them as you prefer.

Note that Syncthing runs as UID 1000 and GID 1000 by default. These may be
altered with the `PUID` and `PGID` environment variables. In addition
the name of the Syncthing instance can be optionally defined by using
`--hostname=syncthing` parameter.

To grant Syncthing additional capabilities without running as root, use the
`PCAP` environment variable with the same syntax as that for `setcap(8)`.
For example, `PCAP=cap_chown,cap_fowner+ep`.

To set a different umask value, use the `UMASK` environment variable. For
example `UMASK=002`.

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Can we just adapt our CLI and Compose examples in the top section to also use host network mode by default? Most people tend to simply copy&paste the very first Compose bits and end up with a setup which breaks local IP discovery.

calmh · June 20, 2025, 8:49am

Go for it