nut-upsd
This is the nut-upsd docker image, which implements the UPS drivers and the upsd daemon from https://networkupstools.org/.
The idea behind this implementation is to have a generic container, which supports monitoring multiple UPS devices from the same container. This is different from other implementations, which are intended to support one (1) container per one (1) UPS.
The drawback of this implementation is that the container can't be easily driven by environment variables. I mean, yes, technically, I could support a gazillion of env vars, but... uhm ... no! :-)
So instead, traditional config files have to be slipped into the container by use of a config volume mount.
how to use
docker run -d \
-p 3493:3493 \
-v /path/to/nut-config:/etc/nut \
[ --privileged | --device ... ] \
gpdm/nut-upsd[:<tag>]
configuration
main config for upsd
As this docker runs only the UPS drivers and the upsd daemon itself, you only need these configuration files:
This docker image cannot be configured through environment variables. You have to use a config volume as shown:
- create the ups.conf, upsd.conf and upsd.users config files with your favorite editor
- store them into a permanent config directory, e.g.
/data/dockers/nut-upsd/config - when running the container, point it mount the config directory as a volume, e.g.
-v /data/dockers/nut-upsd/config:/etc/nut
The container will fail to start when no volume is mounted, or not all needed files are present!
Some sample config files are provided for your conventience in the [master repository] You may use them as a starting point, however I recommed to have a indepth look at the official Network UPS Tools documentation.
device mapping
In order for the ups monitoring to work, you have to map your device tree into the docker container.
privileged mode
Just pass this option to the container at startup.
--privileged
NOTE: This is the least secure approach, as it grants overall privileges to everything.
device mode
Better than going for privileged mode, is to pass just the individual devices into the container.
This can be done by passing --device and --device-cgroup-rule commands to docker.
First, identify the device-id, i.e. by running lsusb:
$ lsusb
Bus 007 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 008 Device 002: ID 0bc2:331a Seagate RSS LLC
Bus 008 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 006 Device 002: ID 0665:5161 Cypress Semiconductor USB to Serial << generic UPS on USB
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 002: ID 051d:0002 American Power Conversion Uninterruptible Power Supply << APC UPS on USB
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 002: ID f400:f400
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
The example above reveals two UPSes attached, one to Bus 5, as device #2, the other on Bus 6, as device #2. This translates to the following device paths:
/dev/bus/usb/005/002
/dev/bus/usb/006/002
Get the device major and minor device number like this:
~$ ls -l /dev/bus/usb/005/002 /dev/bus/usb/006/002
crwxrwxrwx 1 root root 189, 513 Oct 8 22:06 /dev/bus/usb/005/002
crwxrwxrwx 1 root root 189, 641 Oct 8 22:06 /dev/bus/usb/006/002
The values we're looking for is in colums 5 and 6 respectively.
To map these devices now into the container, the devices have to be passed in, together with a control group rule each, matching the major and minor device number.
docker run [ ... ] \
--device /dev/bus/usb/005/002 --device-cgroup-rule='c 189:513 rw'
--device /dev/bus/usb/006/002 --device-cgroup-rule='c 189:641 rw'
[ ... ]