How to change ip address of docker0 bridge interface on Docker Toolbox

To change the IP address Docker will set on it's docker0 interface, you have to use the --bip option which defines the CIDR (eg. --bip=10.32.57.1/24), see "Customize the docker0 bridge" in Docker user guide.

Docker Toolbox uses Boot2Docker (running in a virtual machine) which is based on the Tiny Core Linux OS.

Docker daemon reads /var/lib/boot2docker/profile before starting (see "Local Customisation" in Boot2Docker's FAQ) where a EXTRA_ARGS variable is ready to be filled with your custom settings.

Just add your --bip=... in EXTRA_ARGS's value part and restart the daemon.

The following command (to type in the Docker Quickstart Terminal) will stop the Docker daemon, drop any existing rule, delete the interface, add a --bip option to /var/lib/boot2docker/profile and restart the daemon:

docker-machine ssh default "\    sudo /etc/init.d/docker stop ; \    sudo iptables -t nat -F POSTROUTING ; \    sudo ip link del docker0 ; \    sudo sed -i \"/^EXTRA_ARGS='\\$/a --bip=10.32.57.1/24\" /var/lib/boot2docker/profile ; \    sudo /etc/init.d/docker start \    "

(Content of /var/lib/boot2docker is persisted between Boot2Docker VM restarts so running this command once should suffice)

You can check with:

docker-machine ssh default "ip a show dev docker0"

If anyone needs the same manipulation on Debian (without Boot2Docker thus):

For Sysvinit:

cat >> /etc/default/docker <<EOT# Change Docker network bridge:DOCKER_OPTS="--bip=10.32.57.1/24" # "3257" = "dckr" on a phone keyboardEOT

For systemd:

cat > /etc/systemd/system/docker.service <<'EOT'[Service]EnvironmentFile=-/etc/sysconfig/dockerEnvironmentFile=-/etc/sysconfig/docker-storageEnvironmentFile=-/etc/sysconfig/docker-networkExecStart=ExecStart=/usr/bin/docker daemon -H fd:// $OPTIONS \          $DOCKER_STORAGE_OPTIONS \          $DOCKER_NETWORK_OPTIONS \          $BLOCK_REGISTRY \          $INSECURE_REGISTRYEOTmkdir /etc/sysconfigcat > /etc/sysconfig/docker <<EOTOPTIONS="--bip=10.32.57.1/24"EOTsystemctl daemon-reload

Then (for both Sysvinit and systemd):

service docker stopiptables -t nat -F POSTROUTINGip link del docker0service docker startiptables -t nat -L -n # Check if POSTROUTING table is OK