qoomon/docker-host
Docker container to forward all traffic to the docker host
10M+
Docker Image Tags:
latest
3
3.x.x
Docker image to forward TCP and UDP traffic to the docker host. This
also works for (rootless) podman. This README.md uses the term docker, but you
can read that as both docker
and podman
(it works for both), unless
otherwise specified.
This container will determine docker host address in the following order
Use ip from environment variable DOCKER_HOST
if set
Try to resolve host using DNS names e.g. getent ahostsv4 host.docker.internal
host.docker.internal
host.containers.internal
Defaults to default gateway (ip -4 route show default
)
Ports
By default all ports (1-65535
) are forwarded to docker host.
PORTS
to a space and/or comma separated list of ports and/or port ranges e.g
docker run -e PORTS='443, 8000-9000' ...
.443:8443, 8000-9000:5000-6000
(CONTAINER_PORT:HOST_PORT
).On Linux systems ⚠️
You have to bind your host applications to 0.0.0.0
or bridge
network gateway in addition to 127.0.0.1
.
Use following docker command to get the bridge network gateway IP address
docker network inspect bridge --format='{{( index .IPAM.Config 0).Gateway}}'
NOTE: For (rootless) podman, it's sufficient to bind to localhost, assuming default podman installation.
You might need to configure your firewall of the host system to allow the docker-host container to communicate with the host on your relevant port, see #21.
These examples will send messages from docker container to docker host with netcat
Start netcat
server TCP on port 2323
to receive and display messages
nc -p 2323 -lk
Start netcat
server UDP on port 5353
to receive and display messages
nc -p 5353 -lk -u
Run the dockerhost container.
docker run --rm \
--name 'docker-host' \
--cap-add=NET_ADMIN --cap-add=NET_RAW \
--restart on-failure \
-d qoomon/docker-host
Run your application container and link the dockerhost container.
The dockerhost will be reachable through the domain/link dockerhost
of the dockerhost container
This example will let you send messages to TCPnetcat
server on docker host.
docker run --rm \
--link 'docker-host' \
-it alpine nc 'docker-host' 2323 -v
This example will let you send messages to UDPnetcat
server on docker host.
docker run --rm \
--link 'docker-host' \
-it alpine nc 'docker-host' 5353 -u -v
Create the dockerhost network.
network_name="Network-$RANDOM"
docker network create "$network_name"
Run the dockerhost container within the dockerhost network.
docker run --name "${network_name}-docker-host" \
--cap-add=NET_ADMIN --cap-add=NET_RAW \
--restart on-failure \
--net=${network_name} --network-alias 'docker-host' \
qoomon/docker-host
Run your application container within the dockerhost network.
The dockerhost will be reachable through the domain/link docker-host
of the dockerhost container
This example will let you send messages to TCPnetcat
server on docker host.
docker run --rm \
--link 'docker-host' \
-it alpine nc 'docker-host' 2323 -v
This example will let you send messages to UDPnetcat
server on docker host.
docker run --rm \
--link 'docker-host' \
-it alpine nc 'docker-host' 5353 -u -v
version: '2'
services:
docker-host:
image: qoomon/docker-host
cap_add: [ 'NET_ADMIN', 'NET_RAW' ]
mem_limit: 8M
restart: on-failure
tcp_message_emitter:
depends_on: [ docker-host ]
image: alpine
command: [ "sh", "-c", "while :; do date; sleep 1; done | nc 'docker-host' 2323 -v"]
udp_message_emitter:
depends_on: [ docker-host ]
image: alpine
command: [ "sh", "-c", "while :; do date; sleep 1; done | nc 'docker-host' 5353 -u -v"]
docker pull qoomon/docker-host