[BUG] HTTP/HTTPS gui address configuration

[summerroman]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

I am currently using the docker image lscr.io/linuxserver/syncthing:latest from 05.07.2025, which actually points to version v1.30.0-ls186 which also means version v1.30.0 of syncthing. I installed the container on my qnap nas in container station in a qnap specific brigde mode which allows the container to run in the current subnet of the nas with its own static IPv4 address.

So I wanted to change the default http/https gui listening port from 8384 to the standard https port 443. Configuring the port by setting the gui address in the /config/config.xml or via the official environment variable STGUIADDRESS to 0.0.0.0:443 failed.

The reason for this behavior is the start command for syncthing inside of the container. It is defined in the startup script file /etc/s6-overlay/s6-rc.d/svc-syncthing/run:

#!/usr/bin/with-contenv bash
# shellcheck shell=bash

exec \
    s6-notifyoncheck -d -n 300 -w 1000 -c "nc -z localhost 8384" \
        s6-setuidgid abc syncthing \
        -home=/config -no-browser -no-restart \
        --gui-address="0.0.0.0:8384"

Here you see that the command line argument --gui-address="0.0.0.0:8384" hardcodes the gui address of syncthing. Because of this a manual configuration in the config.xml or via the STGUIADDRESS environment variable have no effect.

So my workaround was to delete the line --gui-address="0.0.0.0:8384" in the startup script.

Expected Behavior

Change the startup script /etc/s6-overlay/s6-rc.d/svc-syncthing/run so that the gui address can be configured in the config.xml configuration file or via the STGUIADDRESS environment variable. The deletion of the --gui-address="0.0.0.0:8384" startup argument will solve this. Beside this, I do not know if the hardcoded definition of the gui address was intended for some reason. In my case I need this feature, because I cannot map the port like in other docker configurations and I don't want to hide the server behind a reverse proxy.

Steps To Reproduce

1. create the container inside the container station of a QNAP NAS
2. define the bride mode under networking and assign a static IPv4 address in the current subnet
3. add the STGUIADDRESS environment variable and set it to 0.0.0.0:443
4. start the container and check the gui listening port

Environment

QNAP QTS 5.2.5.3145
Container Station Version 3.0.9.1038 (2024/11/08)

CPU architecture

x86-64

Docker creation

{
AppArmorProfile:"docker-default"
Args:[]
Config:{
AttachStderr:false
AttachStdin:false
AttachStdout:false
Domainname:""
Entrypoint:[
"/init"
]
Env:[
"PUID=1008"
"S6_CMD_WAIT_FOR_SERVICES_MAXTIME=0"
"S6_STAGE2_HOOK=/docker-mods"
"TZ=Europe/Berlin"
"HOME=/config"
"LSIO_FIRST_PARTY=true"
"PATH=/lsiopy/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
"PGID=1002"
"VIRTUAL_ENV=/lsiopy"
"GUI_PORT=443"
"PS1=$(whoami)@$(hostname):$(pwd)\$ "
"S6_VERBOSITY=1"
"TERM=xterm"
]
ExposedPorts:{
21027/udp:{}
22000/tcp:{}
22000/udp:{}
8384/tcp:{}
}
Hostname:"sync"
Image:"lscr.io/linuxserver/syncthing:latest"
Labels:{
build_version:"Linuxserver.io version:- v1.30.0-ls186 Build-date:- 2025-07-05T02:25:14+00:00"
maintainer:"thelamer"
org.opencontainers.image.authors:"linuxserver.io"
org.opencontainers.image.created:"2025-07-05T02:25:14+00:00"
org.opencontainers.image.description:"[Syncthing](https://syncthing.net) 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."
org.opencontainers.image.documentation:"https://docs.linuxserver.io/images/docker-syncthing"
org.opencontainers.image.licenses:"GPL-3.0-only"
org.opencontainers.image.ref.name:"aa7357236935a19d9f0ce10077e4c703a2f23130"
org.opencontainers.image.revision:"aa7357236935a19d9f0ce10077e4c703a2f23130"
org.opencontainers.image.source:"https://github.com/linuxserver/docker-syncthing"
org.opencontainers.image.title:"Syncthing"
org.opencontainers.image.url:"https://github.com/linuxserver/docker-syncthing/packages"
org.opencontainers.image.vendor:"linuxserver.io"
org.opencontainers.image.version:"v1.30.0-ls186"
}
OpenStdin:true
StdinOnce:false
Tty:true
User:""
Volumes:{
/config:{}
}
WorkingDir:"/"
}
Created:"2025-07-06T12:39:23.375782152Z"
Driver:"overlay2"
ExecIDs:[
"e86066c9ecdc74d970d2674956e8463ed1a20ccbced22d2b1ba73ac052a5673f"
]
GraphDriver:{
Data:{
LowerDir:"/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/2441de4d62f2c46e77e1172cf47c8c090d6c5cb57754239f25fbb12050026264-init/diff:/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/349efd77069f90abe9ab5d10236d03893f7d33737dc7ddec91afca073986d1ce/diff:/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/2e00716df8fe9deb3c11fad9d2e7e8950598bed4bf5b5e2e76e6fc6597b133c6/diff:/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/44ea6bb462b86d559ebdb3838e4386ad4950a912a90fc41b15d09bd45a7ca29b/diff:/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/7869396124ebd8ba91f73209814c6b28022a8277f4ba6ae58c746249b64230e1/diff:/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/0195c433dbd63a6461ab7d9e200941c1ead17a15da90aeb8b4401c4dc70b8f90/diff:/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/b628f1b1bcd5dc8befd8cebd12718357cdaf9f88a77359452f236917e6089b6f/diff:/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/acf14053d942e7fe83ed41b9ce7bb0f92c20f1ba49e0feeb7901ec076d8aedff/diff:/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/9ef292e125515d6001e5f4a7c936c855b0327ef95935dc554803b92ddd7bc00d/diff:/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/99137a190e789da976ccb15f4062d42e57432050394ae4fd4dc5b67a2d76bea9/diff:/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/8c9ec8b83849f1890a50a1e0e23f17c6331ff1535ae9c8f115ab3dbc0da78afa/diff"
MergedDir:"/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/2441de4d62f2c46e77e1172cf47c8c090d6c5cb57754239f25fbb12050026264/merged"
UpperDir:"/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/2441de4d62f2c46e77e1172cf47c8c090d6c5cb57754239f25fbb12050026264/diff"
WorkDir:"/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/overlay2/2441de4d62f2c46e77e1172cf47c8c090d6c5cb57754239f25fbb12050026264/work"
}
Name:"overlay2"
}
HostConfig:{
AutoRemove:false
Binds:[
"/share/sync-user-1:/sync/user-1"
"/share/sync-user-2:/sync/user-2"
"/share/sync-user-3:/sync/user-3"
"/share/sync-user-4:/sync/user-4"
"/share/sync-user-5:/sync/user-5"
"/share/sync:/config"
]
BlkioWeight:0
Cgroup:""
CgroupParent:""
CgroupnsMode:"host"
ConsoleSize:[
0
0
]
ContainerIDFile:""
CpuCount:0
CpuPercent:0
CpuPeriod:0
CpuQuota:0
CpuRealtimePeriod:0
CpuRealtimeRuntime:0
CpuShares:0
CpusetCpus:""
CpusetMems:""
DeviceCgroupRules:[]
Dns:[
"192.168.0.1"
"8.8.8.8"
]
IOMaximumBandwidth:0
IOMaximumIOps:0
Init:false
IpcMode:"private"
Isolation:""
LogConfig:{
Config:{
max-file:"10"
max-size:"10m"
}
Type:"json-file"
}
MaskedPaths:[
"/proc/asound"
"/proc/acpi"
"/proc/kcore"
"/proc/keys"
"/proc/latency_stats"
"/proc/timer_list"
"/proc/timer_stats"
"/proc/sched_debug"
"/proc/scsi"
"/sys/firmware"
"/sys/devices/virtual/powercap"
]
Memory:1073741824
MemoryReservation:536870912
MemorySwap:2147483648
NanoCpus:1000000000
NetworkMode:"qnet-static-bond0-76e39f"
OomKillDisable:false
OomScoreAdj:0
PidMode:""
PortBindings:{}
Privileged:false
PublishAllPorts:false
ReadonlyPaths:[
"/proc/bus"
"/proc/fs"
"/proc/irq"
"/proc/sys"
"/proc/sysrq-trigger"
]
ReadonlyRootfs:false
RestartPolicy:{
MaximumRetryCount:0
Name:"no"
}
Runtime:"runc"
ShmSize:67108864
UTSMode:""
Ulimits:[
{}
]
UsernsMode:""
VolumeDriver:""
VolumesFrom:[]
}
HostnamePath:"/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/containers/77a97e49202bcbd686730100061a06036053d3495b797b8ec1321f6a81ac49b6/hostname"
HostsPath:"/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/containers/77a97e49202bcbd686730100061a06036053d3495b797b8ec1321f6a81ac49b6/hosts"
Id:"77a97e49202bcbd686730100061a06036053d3495b797b8ec1321f6a81ac49b6"
Image:"sha256:7c37a3effa0a718372f75aa5606faf3dc3cff470ac6614ff8564214fc3efddd7"
LogPath:"/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/containers/77a97e49202bcbd686730100061a06036053d3495b797b8ec1321f6a81ac49b6/77a97e49202bcbd686730100061a06036053d3495b797b8ec1321f6a81ac49b6-json.log"
MountLabel:""
Mounts:[
{
Destination:"/sync/user-1"
Mode:""
Propagation:"rprivate"
RW:true
Source:"/share/sync-user-1"
Type:"bind"
}
{
Destination:"/sync/user-2"
Mode:""
Propagation:"rprivate"
RW:true
Source:"/share/sync-user-2"
Type:"bind"
}
{
Destination:"/sync/user-3"
Mode:""
Propagation:"rprivate"
RW:true
Source:"/share/sync-user-3"
Type:"bind"
}
{
Destination:"/sync/user-4"
Mode:""
Propagation:"rprivate"
RW:true
Source:"/share/sync-user-4"
Type:"bind"
}
{
Destination:"/sync/user-5"
Mode:""
Propagation:"rprivate"
RW:true
Source:"/share/sync-user-5"
Type:"bind"
}
{
Destination:"/config"
Mode:""
Propagation:"rprivate"
RW:true
Source:"/share/sync"
Type:"bind"
}
]
Name:"/sync"
NetworkSettings:{
Bridge:""
EndpointID:""
Gateway:""
GlobalIPv6Address:""
GlobalIPv6PrefixLen:0
HairpinMode:false
IPAddress:""
IPPrefixLen:0
IPv6Gateway:""
LinkLocalIPv6Address:""
LinkLocalIPv6PrefixLen:0
MacAddress:""
Networks:{
qnet-static-bond0-76e39f:{
Aliases:[
"77a97e49202b"
"sync"
]
DNSNames:[
"sync"
"77a97e49202b"
]
EndpointID:"3a298947da973509071ab4edcc6a686846778350e638601e35d1a8456875611b"
Gateway:"192.168.0.1"
GlobalIPv6Address:""
GlobalIPv6PrefixLen:0
IPAMConfig:{
IPv4Address:"192.168.0.22"
}
IPAddress:"192.168.0.22"
IPPrefixLen:24
IPv6Gateway:""
MacAddress:"02:42:fd:a6:2d:42"
NetworkID:"6165491d6e1757d11f678330a709feabd75f427b29829e21237acca28373bcd6"
}
}
Ports:{}
SandboxID:"08492daa7b27a7a7220d15c8ee185232850f556cef0ca5e8b94df72a744e1f48"
SandboxKey:"/var/run/docker/netns/08492daa7b27"
}
Path:"/init"
Platform:"linux"
ProcessLabel:""
ResolvConfPath:"/share/CACHEDEV1_DATA/container/container-station-data/lib/docker/containers/77a97e49202bcbd686730100061a06036053d3495b797b8ec1321f6a81ac49b6/resolv.conf"
RestartCount:0
State:{
Dead:false
Error:""
ExitCode:0
FinishedAt:"2025-07-06T13:13:22.383729997Z"
OOMKilled:false
Paused:false
Pid:15535
Restarting:false
Running:true
StartedAt:"2025-07-06T13:14:51.523588224Z"
Status:"running"
}
}

Container logs

[LZTX7] 2025/07/06 09:03:13.156138 api.go:412: INFO: GUI and API listening on [::]:8384
[LZTX7] 2025/07/06 09:03:13.156396 api.go:413: INFO: Access the GUI via the following URL: http://127.0.0.1:8384/

[github-actions]

Thanks for opening your first issue here! Be sure to follow the relevant issue templates, or risk having this issue marked as invalid.

[aptalca]

In my case I need this feature, because I cannot map the port like in other docker configurations and I don't want to hide the server behind a reverse proxy.

I don't follow this. Why can't you map it?

[summerroman]

Because the bridge network mode is a special mode of the QNAP Container Station which treats the container a an own host in the subnet. This mode is a special feature of the QNAP Container Station which is different from the bridge mode in docker containers (although the container station uses docker inside). I could use another network mode and map the ports. But in this case I had to use the ip address of my QNAP NAS and I cant't use the default https port 443 because it is used by the qnap web interface.

[j0nnymoe]

You can disable the qnap webui on port 443. Those modes aren't special to qnap, it's functioning how docker would work on any other platform.

[summerroman]

But I don't want to disable the web ui. I think the question is why the gui address have to be hardcoded? I guess the fix could be easily done by deleting the hard coded configuration. In other docker containers like DLNA server gerbera the port can be configured easily.

[j0nnymoe]

You wouldn't be disabling the webui.
I suspect it was created like that because it's the port that's mentioned within the readme: https://docs.syncthing.net/intro/getting-started.html#configuring (This container is nearly 10 years old. There might've been some limitation or issue back then.)

[summerroman]

I guess there is a misunderstanding. First I don't want to disable the Web UI of my QNAP NAS, because I need it for it's configuration. Second, the configuration describes explicitly that it is possible to configure the Web UI of the syncthing container in the GUI configuration. Beside this in the official syncthing/syncthing docker container it can additionally be configured by the STGUIADDRESS environment variable. I think configuring the web gui port of syncthing should be no problem.

You wrote: This container is nearly 10 years old. There might've been some limitation or issue back then.

So I looked in the history of the repository and the run was changed by a migration and never updated since then. But I think the container should be updated even if the fix is easy. What do you think?

[LinuxServer-CI]

This issue has been automatically marked as stale because it has not had recent activity. This might be due to missing feedback from OP. It will be closed if no further activity occurs. Thank you for your contributions.

[LinuxServer-CI]

This issue is locked due to inactivity