syncthing-openwrt

Init script and usage for ARM based OpenWrt devices.

This document is only applicable for devices with an ARM chip, and is only tested on OpenWrt BarrierBreaker 14.07.

NOTE: As of 2021, OpenWrt has native Syncthing GUI provided as a package. You are recommended to install it under the Software page in OpenWrt's Web UI, instead of following this document. (See #1)

Usage

1. Login to your OpenWrt device via SSH.

2. Download and extract the Syncthing tarball, and copy the syncthing executable to /usr/bin or any other location that are in your PATH environment variable. (Please replace the URL and file names with the latest version. You can find the link on https://syncthing.net .)

   $ curl -k https://github.com/syncthing/syncthing/releases/download/v0.11.9/syncthing-linux-arm-v0.11.9.tar.gz
   $ tar -zxf syncthing-linux-arm-v0.11.9.tar.gz 
   $ cd syncthing-linux-arm-v0.11.9
   $ cp syncthing /usr/bin/

3. Run Syncthing for the first time.

   syncthing

   When you see a message about your Node ID that looks like this:

   [2EQK3] 15:47:15 OK: Ready to synchronize default (read-write)
   [2EQK3] 15:47:15 INFO: Node 2EQK3ZR77PTBQGM44KE7VQIQG7ICXJDEOK34TO3SWOVMUL4QFBHA is "server1" at [dynamic]
   

   You can press Ctrl-C to stop it.

4. If you don't want the Syncthing Web GUI to be accessible from WAN, you can skip 5 and 6.

5. Modify the Syncthing configuration file.

   $ vi ~/.config/syncthing/config.xml

   Look for a section that looks like this:

   <gui enabled="true" tls="false">
      <address>127.0.0.1:8384</address>
   </gui>

   Change it to:

   <gui enabled="true" tls="false">
      <address>0.0.0.0:8384</address>
   </gui>

6. Open TCP port 8384 to WAN. Add the following lines in /etc/config/firewall:

   config rule
            option enabled '1'
            option target 'ACCEPT'
            option src 'wan'
            option proto 'tcp'
            option dest_port '8384'
            option name 'Syncthing Web'
   

7. Download /etc/init.d/syncthing from this repository and copy it to /etc/init.d and make it executable.

   $ curl -k https://github.com/brglng/syncthing-openwrt/raw/master/etc/init.d/syncthing
   $ cp syncthing /etc/init.d
   $ chmod +x /etc/init.d/syncthing

8. Enable and start the syncthing service.

   $ /etc/init.d/syncthing enable
   $ /etc/init.d/syncthing start

9. Open http://your-openwrt-device-address:8384 on your browser.

10. If you have allowed access to your Syncthing Web GUI from WAN, make sure to turn on "GUI Authentication Password" and "Use HTTPS for GUI" in the settings.

11. Open ports 20022/TCP and 21025/UDP to WAN, and set up port forward for port 20022/TCP. Add the following lines in /etc/config/firewall:

    config rule
             option target 'ACCEPT'
             option src 'wan'
             option proto 'tcp'
             option dest_port '22000'
             option name 'Syncthing TCP'
    
    config rule
             option enabled '1'
             option target 'ACCEPT'
             option src 'wan'
             option proto 'udp'
             option dest_port '21025'
             option name 'Syncthing UDP'
    
    config redirect
             option enabled '1'
             option target 'DNAT'
             option src 'wan'
             option dest 'lan'
             option proto 'tcp'
             option src_dport '22000'
             option dest_ip '192.168.1.1'
             option dest_port '22000'
             option name 'Syncthing'