OTBR Docker - entrypoint sed configuration fails, setup-host loops indefinitely

[miloit]

Description

When attempting to configure OTBR port bindings via docker-compose entrypoint with sed commands, the container enters a restart loop. The sed modifications should happen before services start, but instead fail and setup-host loops infinitely.

Environment

• openthread/otbr:latest (openthread/ot-br-posix)
• Docker Compose on DietPi
• ConBee II (dresden_elektronik Thread RCP)
• network_mode: host

Reproduction Steps

docker-compose.yml:

services:
  otbr:
    image: openthread/otbr:latest
    container_name: otbr
cat /tmp/github-issue.txtble but requires post-start scriptalhost only)hout dock
Title: OTBR Docker - entrypoint sed configuration fails, setup-host loops indefinitely

## Description
When attempting to configure OTBR port bindings via docker-compose entrypoint with sed commands, the container enters a restart loop. The sed modifications should happen before services start, but instead fail and setup-host loops infinitely.

## Environment
- openthread/otbr:latest (openthread/ot-br-posix)
- Docker Compose on DietPi
- ConBee II (dresden_elektronik Thread RCP)
- network_mode: host

## Reproduction Steps

**docker-compose.yml:**
```yaml
services:
  otbr:
    image: openthread/otbr:latest
    container_name: otbr
    restart: unless-stopped
    privileged: true
    network_mode: host
    cap_add:
      - NET_ADMIN
    environment:
      - NAT44=0
      - NAT64=0
      - FIREWALL=0
    volumes:
      - /dev:/dev
      - /sys:/sys:ro
    entrypoint: ["/bin/bash", "-c", "sed -i 's/-a 127.0.0.1/-a 0.0.0.0/g' /etc/default/otbr-web; sed -i 's/127.0.0.1/0.0.0.0/g' /etc/default/otbr-agent; exec /app/etc/docker/border-router/setup-host --radio-url 'spinel+hdlc+uart:///dev/serial/by-id/usb-dresden_elektronik_Thread_RCP__ConBee_II__DE2665925-if00?uart-baudrate=115200'"]

Result:

docker logs otbr
sed: can't read /etc/default/otbr-web: No such file or directory

INFRA_IF_NAME=eth0
readonly INFRA_IF_NAME
...

(setup-host loops indefinitely)

Expected Behavior

• sed commands should succeed once config files exist
• setup-host should start once and not loop
• otbr-web and otbr-agent should bind to 0.0.0.0:80 and 0.0.0.0:8081

Current Workaround

Using docker exec after container start works perfectly:

docker exec otbr sed -i 's/-a 127.0.0.1/-a 0.0.0.0/g' /etc/default/otbr-web
docker exec otbr sed -i 's/127.0.0.1/0.0.0.0/g' /etc/default/otbr-agent
docker exec otbr service otbr-web restart
docker exec otbr service otbr-agent restart

Questions

1. Why does /etc/default/otbr-web not exist when entrypoint runs?
2. Why does setup-host loop when started via entrypoint?
3. Is there a proper way to configure OTBR ports via docker-compose without docker exec?

Additional Context

• This is needed to allow external access to OTBR web UI and REST API
• With default config, services only bind to 127.0.0.1 (localhost only)
• The workaround is reliable but requires post-start script

[jwhui]

Hi @miloit,

To answer your questions:

1. Why /etc/default/otbr-web does not exist when entrypoint runs:
   In openthread/otbr, /etc/default/otbr-web and /etc/default/otbr-agent are generated dynamically at runtime by the default container entrypoint script (docker_entrypoint.sh). Overriding entrypoint: in docker-compose.yml replaces that script, so the files are never created.

2. Why setup-host loops indefinitely:
   setup-host is a one-shot host preparation script meant to be run on the host OS to configure sysctl rules (IPv6 RA acceptance and IP forwarding). It does not accept --radio-url or start OTBR services—it simply applies sysctl settings and exits immediately (exit 0). Combined with restart: unless-stopped, Docker continuously restarts the container in an infinite loop.

3. Proper way to configure OTBR ports and addresses:
   We recommend switching to the official openthread/border-router:latest image (s6-overlay based), which natively supports configuring the RCP device, interfaces, and listen addresses/ports via environment variables without needing custom entrypoints or sed:

services:
  otbr:
    image: openthread/border-router:latest
    container_name: otbr
    restart: unless-stopped
    privileged: true
    network_mode: host
    environment:
      - OT_RCP_DEVICE=spinel+hdlc+uart:///dev/serial/by-id/usb-dresden_elektronik_Thread_RCP__ConBee_II__DE2665925-if00?uart-baudrate=115200
      - OT_INFRA_IF=eth0
      - OT_THREAD_IF=wpan0
      - OT_WEB_LISTEN_ADDR=0.0.0.0
      - OT_WEB_LISTEN_PORT=80
      - OT_REST_LISTEN_ADDR=0.0.0.0
      - OT_REST_LISTEN_PORT=8081
    volumes:
      - /dev:/dev