candicandi / alpine-dhcp

Container for ISC-DHCP server built on Alpine Linux + s6.

Alpine-DHCP

Container for Alpine Linux + ISC DHCP server

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This image containerizes the ISC DHCP to quickly deploy a DHCP server to serve/manage IP configurations to the devices in the network.

Based on Alpine Linux from my alpine-s6 image with the s6 init system overlayed in it.

The image is tagged respectively for the following architectures,

• armhf
• armv7l
• aarch64
• x86_64 (retagged as the latest )

non-x86_64 builds have embedded binfmt_misc support and contain the qemu-user-static binary that allows for running it also inside an x86_64 environment that has it.

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Get the Image

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Pull the image for your architecture it's already available from Docker Hub.

# make pull
docker pull woahbase/alpine-dhcp:x86_64

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Run

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If you want to run images for other architectures, you will need to have binfmt support configured for your machine. multiarch, has made it easy for us containing that into a docker container.

# make regbinfmt
docker run --rm --privileged multiarch/qemu-user-static:register --reset

Without the above, you can still run the image that is made for your architecture, e.g for an x86_64 machine..

ISC-DHCP needs the --network=host flag to have access to the NIC of the host machine. Optionally, pass the interface to bind to in the INTERFACES environment variable. A sample configuration is provied in the config directory, by default this gets mounted as the /etc/dhcp/dhcpd.conf.

Running make starts the service.

# make
docker run --rm -it \
  --name docker_dhcp --hostname dhcp \
  --network=host \
  -c 128 -m 256m \
  -e INTERFACES=eth0 \
  -e PGID=100 -e PUID=1000 \
  -e TZ=Asia/Kolkata \
  -p 67:67/tcp \
  -p 67:67/udp \
  -v config/dhcpd.conf:/etc/dhcp/dhcpd.conf \
  woahbase/alpine-dhcp:x86_64

Running make shell gets a shell, but doesn't start the service, so additional testing/debugging can be done before starting it manually.

# make shell
docker run --rm -it \
  --entrypoint /bin/bash \
  --name docker_dhcp --hostname dhcp \
  --network=host \
  -c 128 -m 256m \
  -e INTERFACES=eth0 \
  -e PGID=100 -e PUID=1000 \
  -e TZ=Asia/Kolkata \
  -p 67:67/tcp \
  -p 67:67/udp \
  -v config/dhcpd.conf:/etc/dhcp/dhcpd.conf \
  woahbase/alpine-dhcp:x86_64

Stop the container with a timeout, (defaults to 2 seconds)

# make stop
docker stop -t 2 docker_dhcp

Removes the container, (always better to stop it first and -f only when needed most)

# make rm
docker rm -f docker_dhcp

Restart the container with

# make restart
docker restart docker_dhcp

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Shell access

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Get a shell inside a already running container,

# make debug
docker exec -it docker_dhcp /bin/bash

set user or login as root,

# make rdebug
docker exec -u root -it docker_dhcp /bin/bash

To check logs of a running container in real time

# make logs
docker logs -f docker_dhcp

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Development

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If you have the repository access, you can clone and build the image yourself for your own system, and can push after.

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Setup

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Before you clone the repo, you must have Git, GNU make, and Docker setup on the machine.

git clone https://github.com/woahbase/alpine-dhcp
cd alpine-dhcp

You can always skip installing make but you will have to type the whole docker commands then instead of using the sweet make targets.

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Build

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You need to have binfmt_misc configured in your system to be able to build images for other architectures.

Otherwise to locally build the image for your system. [ARCH defaults to x86_64, need to be explicit when building for other architectures.]

# make ARCH=x86_64 build
# sets up binfmt if not x86_64
docker build --rm --compress --force-rm \
  --no-cache=true --pull \
  -f ./Dockerfile_x86_64 \
  --build-arg DOCKERSRC=woahbase/alpine-s6:x86_64 \
  --build-arg PGID=1000 \
  --build-arg PUID=1000 \
  -t woahbase/alpine-dhcp:x86_64 \
  .

To check if its working..

# make ARCH=x86_64 test
docker run --rm -it \
  --entrypoint /bin/bash \
  --name docker_dhcp --hostname dhcp \
  -e PGID=1000 -e PUID=1000 \
  -v config/dhcpd.conf:/etc/dhcp/dhcpd.conf \
  woahbase/alpine-dhcp:x86_64 \
  -ec dhcpd --version

And finally, if you have push access,

# make ARCH=x86_64 push
docker push woahbase/alpine-dhcp:x86_64

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Maintenance

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Sources at Github. Built at Travis-CI.org (armhf / x64 builds). Images at Docker hub. Metadata at Microbadger.

Maintained by WOAHBase.