The LinuxServer.io team brings you another container release featuring:

• regular and timely application updates
• easy user mappings (PGID, PUID)
• custom base image with s6 overlay
• weekly base OS updates with common layers across the entire LinuxServer.io ecosystem to minimise space usage, down time and bandwidth
• regular security updates

Find us at:

• Blog - all the things you can do with our containers including How-To guides, opinions and much more!
• Discord - realtime support / chat with the community and the team.
• Discourse - post on our community forum.
• Fleet - an online web interface which displays all of our maintained images.
• GitHub - view the source for all of our repositories.
• Open Collective - please consider helping us by either donating or contributing to our budget

linuxserver/syncthing

Syncthing replaces proprietary sync and cloud services with something open, trustworthy and decentralized. Your data is your data alone and you deserve to choose where it is stored, if it is shared with some third party and how it's transmitted over the Internet.

Supported Architectures

Our images support multiple architectures such as x86-64, arm64 and armhf. We utilise the docker manifest for multi-platform awareness. More information is available from docker here and our announcement here.

Simply pulling ghcr.io/linuxserver/syncthing should retrieve the correct image for your arch, but you can also pull specific arch images via tags.

The architectures supported by this image are:

Architecture	Tag
x86-64	amd64-latest
arm64	arm64v8-latest
armhf	arm32v7-latest

Application Setup

**Note: ** The Syncthing devs highly suggest setting a password for this container as it listens on 0.0.0.0. To do this go to Actions -> Settings -> set user/password for the webUI.

Usage

Here are some example snippets to help you get started creating a container.

docker-compose (recommended, click here for more info)

---
version: "2.1"
services:
  syncthing:
    image: ghcr.io/linuxserver/syncthing
    container_name: syncthing
    hostname: syncthing #optional
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=Europe/London
    volumes:
      - /path/to/appdata/config:/config
      - /path/to/data1:/data1
      - /path/to/data2:/data2
    ports:
      - 8384:8384
      - 22000:22000/tcp
      - 22000:22000/udp
      - 21027:21027/udp
    restart: unless-stopped

docker cli (click here for more info)

docker run -d \
  --name=syncthing \
  --hostname=syncthing `#optional` \
  -e PUID=1000 \
  -e PGID=1000 \
  -e TZ=Europe/London \
  -p 8384:8384 \
  -p 22000:22000/tcp \
  -p 22000:22000/udp \
  -p 21027:21027/udp \
  -v /path/to/appdata/config:/config \
  -v /path/to/data1:/data1 \
  -v /path/to/data2:/data2 \
  --restart unless-stopped \
  ghcr.io/linuxserver/syncthing

Parameters

Container images are configured using parameters passed at runtime (such as those above). These parameters are separated by a colon and indicate <external>:<internal> respectively. For example, -p 8080:80 would expose port 80 from inside the container to be accessible from the host's IP on port 8080 outside the container.

Parameter	Function
--hostname=	Optionally the hostname can be defined.
-p 8384	Application WebUI
-p 22000/tcp	Listening port (TCP)
-p 22000/udp	Listening port (UDP)
-p 21027/udp	Protocol discovery
-e PUID=1000	for UserID - see below for explanation
-e PGID=1000	for GroupID - see below for explanation
-e TZ=Europe/London	Specify a timezone to use EG Europe/London.
-v /config	Configuration files.
-v /data1	Data1
-v /data2	Data2

Environment variables from files (Docker secrets)

You can set any environment variable from a file by using a special prepend FILE__.

As an example:

-e FILE__PASSWORD=/run/secrets/mysecretpassword

Will set the environment variable PASSWORD based on the contents of the /run/secrets/mysecretpassword file.

Umask for running applications

For all of our images we provide the ability to override the default umask settings for services started within the containers using the optional -e UMASK=022 setting. Keep in mind umask is not chmod it subtracts from permissions based on it's value it does not add. Please read up here before asking for support.

User / Group Identifiers

When using volumes (-v flags) permissions issues can arise between the host OS and the container, we avoid this issue by allowing you to specify the user PUID and group PGID.

Ensure any volume directories on the host are owned by the same user you specify and any permissions issues will vanish like magic.

In this instance PUID=1000 and PGID=1000, to find yours use id user as below:

  $ id username
    uid=1000(dockeruser) gid=1000(dockergroup) groups=1000(dockergroup)

Docker Mods

We publish various Docker Mods to enable additional functionality within the containers. The list of Mods available for this image (if any) as well as universal mods that can be applied to any one of our images can be accessed via the dynamic badges above.

Support Info

• Shell access whilst the container is running: docker exec -it syncthing /bin/bash
• To monitor the logs of the container in realtime: docker logs -f syncthing
• container version number
  • docker inspect -f '{{ index .Config.Labels "build_version" }}' syncthing
• image version number
  • docker inspect -f '{{ index .Config.Labels "build_version" }}' ghcr.io/linuxserver/syncthing

Updating Info

Most of our images are static, versioned, and require an image update and container recreation to update the app inside. With some exceptions (ie. nextcloud, plex), we do not recommend or support updating apps inside the container. Please consult the Application Setup section above to see if it is recommended for the image.

Below are the instructions for updating containers:

Via Docker Compose

• Update all images: docker-compose pull
  • or update a single image: docker-compose pull syncthing
• Let compose update all containers as necessary: docker-compose up -d
  • or update a single container: docker-compose up -d syncthing
• You can also remove the old dangling images: docker image prune

Via Docker Run

• Update the image: docker pull ghcr.io/linuxserver/syncthing
• Stop the running container: docker stop syncthing
• Delete the container: docker rm syncthing
• Recreate a new container with the same docker run parameters as instructed above (if mapped correctly to a host folder, your /config folder and settings will be preserved)
• You can also remove the old dangling images: docker image prune

Via Watchtower auto-updater (only use if you don't remember the original parameters)

• Pull the latest image at its tag and replace it with the same env variables in one run:

  docker run --rm \
  -v /var/run/docker.sock:/var/run/docker.sock \
  containrrr/watchtower \
  --run-once syncthing

• You can also remove the old dangling images: docker image prune

Note: We do not endorse the use of Watchtower as a solution to automated updates of existing Docker containers. In fact we generally discourage automated updates. However, this is a useful tool for one-time manual updates of containers where you have forgotten the original parameters. In the long term, we highly recommend using Docker Compose.

Image Update Notifications - Diun (Docker Image Update Notifier)

• We recommend Diun for update notifications. Other tools that automatically update containers unattended are not recommended or supported.

Building locally

If you want to make local modifications to these images for development purposes or just to customize the logic:

git clone https://github.com/linuxserver/docker-syncthing.git
cd docker-syncthing
docker build \
  --no-cache \
  --pull \
  -t ghcr.io/linuxserver/syncthing:latest .

The ARM variants can be built on x86_64 hardware using multiarch/qemu-user-static

docker run --rm --privileged multiarch/qemu-user-static:register --reset

Once registered you can define the dockerfile to use with -f Dockerfile.aarch64.

Versions

• 12.05.21: - Remove sysctl parameter again
• 03.05.21: - Raise maximum UDP buffer size.
• 03.05.21: - Add port mapping for 22000/udp.
• 29.01.21: - Deprecate UMASK_SET in favor of UMASK in baseimage, see above for more information.
• 23.01.21: - Rebasing to alpine 3.13.
• 15.09.20: - Use go from alpine edge repo to compile. Remove duplicate UMASK env var. Add hostname setting.
• 01.06.20: - Rebasing to alpine 3.12.
• 19.12.19: - Rebasing to alpine 3.11.
• 28.06.19: - Rebasing to alpine 3.10.
• 23.03.19: - Switching to new Base images, shift to arm32v7 tag.
• 05.03.19: - Update Build process for v1.1.0 release.
• 22.02.19: - Rebasing to alpine 3.9.
• 16.01.19: - Add pipeline logic and multi arch.
• 30.07.18: - Rebase to alpine 3.8 and use buildstage.
• 13.12.17: - Rebase to alpine 3.7.
• 25.10.17: - Add env for manual setting of umask.
• 29.07.17: - Simplify build structure as symlinks failing on > 0.14.32
• 28.05.17: - Rebase to alpine 3.6.
• 08.02.17: - Rebase to alpine 3.5.
• 01.11.16: - Switch to compiling latest version from git source.
• 14.10.16: - Add version layer information.
• 30.09.16: - Fix umask.
• 09.09.16: - Add layer badges to README.
• 28.08.16: - Add badges to README.
• 11.08.16: - Rebase to alpine linux.
• 18.12.15: - Initial testing / release (IronicBadger)
• 24.09.15: - Inital dev complete (Lonix)