OTBR web interface binds to localhost instead of 0.0.0.0 inside Docker

[miloit]

Describe the bug

When running OTBR in Docker with OTBR_WEB_BIND_ADDR=0.0.0.0 and OTBR_WEB_PORT=8081, the web service still binds only to localhost:8080. This prevents accessing the web UI from other devices on the network.

Steps to reproduce

Create otbr-env.list with:

OTBR_WEB_BIND_ADDR=0.0.0.0
OTBR_WEB_PORT=8081

Run Docker container:

docker run --name=otbr --detach \
  --network=host \
  --cap-add=NET_ADMIN \
  --device=/dev/ttyACM0 \
  --device=/dev/net/tun \
  --volume=/var/lib/otbr:/data \
  --env-file=/opt/otbr/otbr-env.list \
  --restart=always \
  openthread/border-router

Check listening ports:

sudo lsof -i :8080

Observed behavior

otbr-web  PID  root  3u  IPv4  ...  TCP localhost:8080 (LISTEN)

The web server only listens on 127.0.0.1 instead of all interfaces (0.0.0.0).

Expected behavior

otbr-web should listen on 0.0.0.0:8080 (or :8081) so the web UI is reachable from other devices on the network.

Environment

OTBR Docker image: openthread/border-router:latest

Additional context

Using --network=host, so port mapping should not be an issue.

Changing OTBR_WEB_BIND_ADDR inside otbr-env.list does not appear to take effect.

[jwhui]

It seems that you are using environment variable names that are not recognized by the official OTBR Docker image startup scripts.

In the official openthread/border-router Docker image, the variables for configuring the web interface are:

• OT_WEB_LISTEN_ADDR (instead of OTBR_WEB_BIND_ADDR)
• OT_WEB_LISTEN_PORT (instead of OTBR_WEB_PORT)

To fix this, please update your otbr-env.list with the following:

• OT_WEB_LISTEN_ADDR=0.0.0.0
• OT_WEB_LISTEN_PORT=8080

You can verify the variables used in the startup script here:
https://github.com/openthread/ot-br-posix/blob/main/etc/docker/border-router/rootfs/etc/s6-overlay/s6-rc.d/otbr-web/run

Hope that helps.