Docker run command forces UPS to move to different device path

[jm20122012]

Just downloaded the docker container on CentOS 8. When I plug in my UPS, it gets assigned to "/dev/bus/usb/00x/00x". When I use the docker run command I use:

docker run --name tripplite --detach --publish 3943:3943 --device /dev/bus/usb/00x/00x -e UPS_NAME="Tripplite" -e UPS_DRIVER=usbhid-ups -e UPS_DESC=Tripplite -e API_USER="upsmon" -e API_PASSWORD="xxxxx" upshift/nut-upsd

If the device path was originally "/dev/bus/usb/002/001" it will get reassigned to "/dev/bus/usb/002/002" after starting the docker container, which results in never ending "Poll UPS [Tripplite@localhost] failed - Data stale" messages in the log. I'm assuming because the UPS has moved to a new device path as a result of the run command forcing it to move.

Not sure what to do to fix this.

[jlazkano]

Hello,

I have same problem, I have fixed the UPS to a static dev with udev and this is the device line in the compose:

devices: - /dev/apc-sai:/dev/bus/usb/004/003

If I reboot the host, and the device goes to different bus, it can not connect, like in this example:

$ lsusb | grep Power Bus 004 Device 002: ID 051d:0002 American Power Conversion Uninterruptible Power Supply

I need to change the compose line to the new bus:

devices: - /dev/apc-sai:/dev/bus/usb/004/002

How could we fix this?

How do you configure your compose files?

[KC-inDomus]

same problem here. will follow

[yetkinergun]

just pass the full usb path like this:

devices:
      - /dev/bus/usb:/dev/bus/usb

[Peppercorn27]

This is because alpine images do NOT follow symlinks for device nodes, as documented here - moby/moby#13840 (comment)

To fix this, I rebased the image onto Debian-slim, feel free to use. Clone the repo and adjust the Dockerfile to the following:

FROM debian:12-slim AS build

ENV NUT_VERSION="2.8.3"

RUN set -ex; \
        # run dependencies
        apt update; \
        apt install -y \
                wget \
                build-essential \
                libusb-dev \
        ; \
        # download and extract
        cd /tmp; \
        wget http://www.networkupstools.org/source/2.8/nut-$NUT_VERSION.tar.gz; \
        tar xfz nut-$NUT_VERSION.tar.gz; \
        cd nut-$NUT_VERSION \
        ; \
        # build
        ./configure \
                --prefix=/usr \
                --sysconfdir=/etc/nut \
                --disable-dependency-tracking \
                --enable-strip \
                --disable-static \
                --with-all=no \
                --with-usb=yes \
                --datadir=/usr/share/nut \
                --with-drvpath=/usr/share/nut \
                --with-statepath=/var/run/nut \
                --with-user=nut \
                --with-group=nut \
        ; \
        # install
        mkdir /tmp/nut; make -j4 DESTDIR=/tmp/nut install

FROM debian:12-slim AS release
ENV NUT_VERSION="2.8.3"

ENV UPS_NAME="ups"
ENV UPS_DESC="UPS"
ENV UPS_DRIVER="usbhid-ups"
ENV UPS_PORT="auto"

ENV API_PASSWORD=""
ENV ADMIN_PASSWORD=""

ENV SHUTDOWN_CMD="echo 'System shutdown not configured!'"

COPY --from=build /tmp/nut/etc /etc
COPY --from=build /tmp/nut/lib /lib
COPY --from=build /tmp/nut/usr /usr

RUN set -ex; \
        apt update; apt upgrade -y ; apt install -y libusb-dev; \
        groupadd -r nut; \
        useradd -r --home /var/run/nut -g nut nut; \
        chgrp -R nut /etc/nut; \
        chmod -R o-rwx /etc/nut; \
        install -d -m 750 -o nut -g nut /var/run/nut

COPY src/docker-entrypoint /usr/local/bin/
ENTRYPOINT ["docker-entrypoint"]

WORKDIR /var/run/nut

EXPOSE 3493

Then compose:

  nuts:
    container_name: nuts
    build: ./nuts-dev/nut-upsd # path to my custom dockerfile
    ports:
      - 3493:3493
    devices:
      - /dev/usb-NUT:/dev/bus/usb/007/007:rw #007/007 is arbitrary, pick anything
    networks:
      <your network>:
    environment:
      - UPS_DRIVER=nutdrv_qx
      - MAXAGE=25
    restart: unless-stopped

Where /dev/usb-NUT is a symlink to my usb connected UPS created with a udev rule:
(replace the ATTRs with you own device lsusb can help)

SUBSYSTEM=="usb", SUBSYSTEMS=="usb", ATTR{idVendor}=="0665", ATTR{idProduct}=="5161", SYMLINK+="usb-NUT"

This approach will survive reboots where the device changes path, eg /dev/bus/usb/001/002 to /dev/bus/usb/002/002 as the docker engine will re-resolve the symlink when the container auto-restarts on boot, no need to rebuild the container or do anything.