A DHCP client container running as a root user based on Fedora 26 Boltron.
systemctl start dhcp-client-container
docker run --net=host --cap-add=net_admin dhcp-client-container
or, if only a defined list of interfaces should be configured be dhclient:
docker run --net=host --cap-add=net_admin -e INTERFACES="enp0s25 wlan0" dhcp-client-container
To run this container in OpenShift, you need to change the RunAsUser option in the restricted Security Context Constraint (SCC) from MustRunAsRange to RunAsAny. This is because dhclient needs to be run as root. Do it by running:
oc login -u system:admin
oc project default
oc edit scc restricted
Find RunAsUser and change its value from MustRunAsRange to RunAsAny.
Then you will be able to run the container using the openshift-template.yml template in this repo:
oc login -u developer
oc create -f openshift-template.yml
Notes: This container needs to be run with "--net=host --cap_add=net_admin" so that the network devices of the host are visible inside the container and can be configured.
dhclient will attempt to configure all network interfaces unless an INTERFACES variable containing the names of the interfaces to use is supplied on the docker commandline. In the standalone container usecase the means that the file /usr/lib/systemd/system/dhcp-client-container.service needs to be edited.
This dhcp-client container doesn't require NetworkManager to be able to set IP adresses, which minimizes the the package requirements and the memory footprint but makes configuration somewhat harder.