Syncthing Docker image

Syncthing Docker image for RaspberryPi / amd64 systems.

Syncthing replaces proprietary sync and cloud services with something open, trustworthy and decentralized.

See Syncthing website for more.

Tested on following archs:

• x64

Following arch are missing tests:

• arm32v6
• armv7

Available image tags

• nventiveux/syncthing
  • latest, v2.0.10 (Dockerfile)

Usage

Run the container manually (select tag according to the target architecture):

{
mkdir -p "${HOME}/Sync";
docker run \
  -d \
  --name syncthing \
  -p 8384:8384/tcp \
  -p 22000:22000/tcp \
  -p 21027:21027/udp \
  -v syncthing_config:/etc/syncthing \
  -v "${HOME}/Sync":/var/lib/syncthing \
  nventiveux/syncthing:latest;
}

Open the administration website with https://localhost:8384/ and connect using admin / admin.

This will make available for syncing all folders within ~/Sync. You may be interested to adapt environment variables SYNCTHING_USER_UID and SYNCTHING_GROUP_GID to match your user UID / GID at the host (verify with id).

Persisting data

Following paths within the container should be persisted:

• /var/lib/syncthing holds synced content.
• /etc/syncthing holds the syncthing configuration.

Network ports

• Default ports:
  • 21027/udp --> Local discovery (see Known issues)
  • 22000/tcp --> Sync protocol
  • 8384/tcp --> Admin interface

Environment variables

You can configure Syncthing injecting following environment variables:

Variable	Description	Default
SYNCTHING_USER	Name of container user	syncthing
SYNCTHING_USER_UID	Map container user to this UID	1000
SYNCTHING_GROUP	Name of container user primary group	syncthing
SYNCTHING_GROUP_GID	Map container user primary group to this GID	1000
SYNCTHING_ADMIN_USER	Admin username	admin
SYNCTHING_ADMIN_PASSWORD	Admin password	admin

Example to set another password for the admin user:

docker run \
  ...
  -e SYNCTHING_ADMIN_PASSWORD="anotherpassword" \
  ...

Known issues

• Local discovery does not work without --network=host. Need more testing if this can be avoided.

Contribute

Pre-requisites:

• Python >=3.11
• Rye
• make
• Bash >=4
• Git >=2.18

Prepare your environment:

make install

Tweak Dockerfile to your convenience.

Note: if you are upgrading Syncthing to a newer version, also sync the config file version !

Commit changes and submit a Pull Request.

Releasing a new version

Bump the version using:

git switch -c release/next
make release version=<VERSION>
git commit -a -m "feat(core): bump syncthing to <VERSION>"
# Open a pull request
# Tests...

Release:

uv run cz bump --changelog <VERSION>
git push origin -u --tags HEAD

References

• Inspiration taken from tianon/dockerfiles.