Is there a way to force docker-machine to create vm with a specific ip?

Question

Is there a way to force docker-machine to create the docker vm with a specific ip (assuming that ip is available)?

Answer 1

That is actively requested in docker/machine issue 1709

I want to be able to specify the IP address of a VM (i.e. the value that's listed under "URL" in docker-machine ls) when I create it with docker-machine create.

I want this because I've been relying on boot2docker's default address of 192.168.59.103, but now it varies from machine to machine.

The current workaround:

My virtualbox has dhcp range 192.168.99.100 - 255 and I want to set an IP before 100.

I've found a simple trick to set a static IP: after create a machine, I run this command and restart the machine:

echo "ifconfig eth1 192.168.99.50 netmask 255.255.255.0 broadcast 192.168.99.255 up" | docker-machine ssh prova-discovery sudo tee /var/lib/boot2docker/bootsync.sh > /dev/null

This command create a file bootsync.sh that is searched by boot2docker startup scripts and executed.

Now during machine boot the command is executed and set static IP.

docker-machine ls
NAME              ACTIVE   DRIVER       STATE     URL                                      SWARM
test-1                      -        virtualbox     Running   tcp://192.168.99.50:2376      test-1 (master)

Michele Tedeschi (micheletedeschi) adds

I've updated the commands with:

echo "kill `more /var/run/udhcpc.eth1.pid`\nifconfig eth1 192.168.99.50 netmask 255.255.255.0 broadcast 192.168.99.255 up" | docker-machine ssh prova-discovery sudo tee /var/lib/boot2docker/bootsync.sh > /dev/null

then run command (only the first time)

docker-machine regenerate-certs prova-discovery

now the IP will not be changed by the DHCP

(replace prova-discovery by the name of your docker-machine)

---

Here is the (Windows) script (dmvbf.bat) I now use, based on what is above:

@echo off
setlocal enabledelayedexpansion
set machine=%1
if "%machine%" == "" (
    echo dmvbf expects a machine name
    exit /b 1
)
set ipx=%2
if "%ipx%" == "" (
    echo dmvbf x missing ^(for 192.168.x.y^)
    exit /b 2
)
set ipy=%3
if "%ipy%" == "" (
    echo dmvbf y missing ^(for 192.168.x.y^)
    exit /b 3
)

echo kill $(more /var/run/udhcpc.eth1.pid) | docker-machine ssh %machine% sudo tee /var/lib/boot2docker/bootsync.sh >NUL
echo ifconfig eth1 192.168.%ipx%.%ipy% netmask 255.255.255.0 broadcast 192.168.%ipx%.255 up | docker-machine ssh %machine% sudo tee -a /var/lib/boot2docker/bootsync.sh >NUL
echo route add default gw <gateway ip address here> | docker-machine ssh %machine% sudo tee -a /var/lib/boot2docker/bootsync.sh >NUL

docker-machine ssh %machine% "sudo cat /var/run/udhcpc.eth1.pid | xargs sudo kill"

docker-machine ssh %machine% "sudo ifconfig eth1 192.168.%ipx%.%ipy% netmask 255.255.255.0 broadcast 192.168.%ipx%.255 up"

(Note: on Windows 10, Monty Wild comments that it is udhcpc.eth0.pid, not udhcpc.eth1.pid)

I start the vm (docker-machine start <machine-name>), and then:

 dmvbf <machine-name> 99 101

I do that only once.

At the next docker-machine start <machine-name>, the IP will be 192.168.99.101.

Answer 2

The script below uses default as name of the machine and 10.100.1.100 as the static IP address.

cat << EOF | docker-machine ssh default sudo tee /var/lib/boot2docker/bootsync.sh > /dev/null
ifconfig eth1 10.100.1.100 netmask 255.255.255.0 broadcast 10.100.1.255 up
ip route add default via 10.100.1.1
EOF

Restart the machine:

docker-machine restart default

Regenerate the certificates:

docker-machine regenerate-certs default -f

Finally, show the environment variables:

docker-machine env default

Answer 3

Yes, there is an option to create with specific ip. All you need to do is specify ip/ip-range with --virtualbox-hostonly-cidr option.

For example:

• when you want to assign specific ip, let say you want to assign 10.15.1.24, then appropriate config will be (the most important thing is the mask that we are using here. For specific ip you need to set subnet mask to 32) :

  docker-machine create --driver virtualbox --virtualbox-hostonly-cidr "10.15.1.24/32" dev

• if you want to pick an ip from specific ip range, then you need to use appropriate subnet mask.

Answer 4

My workaround was to watch what VBoxNet the docker machine was attached to and then I went into VirtualBox to reset the DHCP range to deliver only the IP I wanted the machine to have.

Answer 5

I changed the DHCP range of VirtualBox. Made both upperbound and lowerbound to 192.168.99.100 and restarted the docker machine. To change the range go to VirtualBox->Files->host network manager->chose the appropriate adapter->change the upperbound.