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Build boot2docker.iso with VirtualBox Guest Additions

Allows me to mount /Users into boot2docker which is incredibly useful for my local Docker environment under Mac OSX. So from Mac I can do sth like this:
docker run -v /Users/mattes/somedir:/data/somedir [..].

This Dockerfile will download the latest boot2docker image (see FROM boot2docker/boot2docker) and adds VirtualBox Guest Additions for your running VirtualBox version.

See also boot2docker/boot2docker#284.

I tried to make the mount permanent from within the VirtualBox GUI (see screenshot) but that didn't work. So I added the mount logic to $ROOTFS/etc/rc.d/vbox-guest-additions-permanent-mount (see Dockerfile.tmpl)

See build log here

# generate Dockerfile from Dockerfile.tmpl
chmod +x

# build the actual boot2docker.iso with virtual box guest additions
docker build -t mattes/boot2docker-vbga .

# the following line is proposed in many tutorials, but does not work for me
# (it outputs an iso that won't work)
docker run -i -t --rm mattes/boot2docker-vbga > boot2docker.iso

# so I do:
docker run -i -t --rm mattes/boot2docker-vbga /bin/bash
# then in a second shell:
docker cp <Container-ID>:boot2docker.iso boot2docker.iso

# use the new boot2docker.iso
boot2docker stop
mv ~/.boot2docker/boot2docker.iso ~/.boot2docker/boot2docker.iso.backup
mv boot2docker.iso ~/.boot2docker/boot2docker.iso
VBoxManage sharedfolder add boot2docker-vm -name home -hostpath /Users
boot2docker up
boot2docker ssh "ls /Users" # to verify if it worked
#!/usr/bin/env sh
local VER
VER=$(VBoxManage -v | awk -F "r" '{print $1}')
if [ -z "$VER" ]; then
echo "ERROR"
echo "$VER"
local VER
if [ ! "$LATEST_RELEASE" = "ERROR" ]; then
sed "s/\$VBOX_VERSION/$VER/g" Dockerfile.tmpl > Dockerfile
echo "WUH WOH"
# using VirtualBox version $VBOX_VERSION
FROM boot2docker/boot2docker
RUN apt-get install p7zip-full
RUN mkdir -p /vboxguest && \
cd /vboxguest && \
curl -L -o vboxguest.iso$VBOX_VERSION/VBoxGuestAdditions_$VBOX_VERSION.iso && \
7z x vboxguest.iso -ir'!' && \
sh --noexec --target . && \
mkdir x86 && cd x86 && tar xvjf ../VBoxGuestAdditions-x86.tar.bz2 && cd .. && \
mkdir amd64 && cd amd64 && tar xvjf ../VBoxGuestAdditions-amd64.tar.bz2 && cd .. && \
cd amd64/src/vboxguest-$VBOX_VERSION && KERN_DIR=/linux-kernel/ make && cd ../../.. && \
cp amd64/src/vboxguest-$VBOX_VERSION/*.ko $ROOTFS/lib/modules/$KERNEL_VERSION-tinycore64 && \
mkdir -p $ROOTFS/sbin && cp x86/lib/VBoxGuestAdditions/mount.vboxsf $ROOTFS/sbin/
RUN echo "" >> $ROOTFS/etc/motd; \
echo " boot2docker with VirtualBox guest additions version $VBOX_VERSION" >> $ROOTFS/etc/motd; \
echo "" >> $ROOTFS/etc/motd
# make mount permanent @todo it works, but its ugly. where should this go?
RUN echo '#!/bin/sh' >> $ROOTFS/etc/rc.d/vbox-guest-additions-permanent-mount; \
echo 'sudo modprobe vboxsf && sudo mkdir /Users && sudo mount -t vboxsf home /Users' >> $ROOTFS/etc/rc.d/vbox-guest-additions-permanent-mount
RUN chmod +x $ROOTFS/etc/rc.d/vbox-guest-additions-permanent-mount
RUN echo '/etc/rc.d/vbox-guest-additions-permanent-mount' >> $ROOTFS/opt/
RUN depmod -a -b $ROOTFS $KERNEL_VERSION-tinycore64
CMD ["cat", "boot2docker.iso"]
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Thanks for this info. I have a slight issue in that I'm attempting to mount a different directory, however editing the /etc/rc.d/vbox-guest-additions-permanent-mount file, saving & restarting the box, causes the changes to this file to get lost. Do you know why this might be?

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mattes commented Jul 7, 2014

Sorry, I overlooked your comment. I don't think saving & restarting works in this case. You would need to build a complete new .iso with the instructions above.

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mitar commented Jul 12, 2014

Have you read here:

It seems automatic mounting works a bit differently on Linux, than manual mounting.

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mitar commented Jul 13, 2014

I discovered an issue with using VirtualBox Guest Additions and nginx. I am using volumes to map my Wordpress blog into the container so that I can develop easily. And I use nginx to server PHP and static files. I discovered that for static files if I change them outside the container, nginx still servers the old file. File inside the container changes, only nginx servers the old version. After some debugging I discovered that sendfile option was the reason. It was turned on and it seems it does not work well together with all this VirtualBox sharing and volume mapping combination. After I disabled sendfile nginx servers the latest version of the file.

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Thanks for the info! It made using fig possible for me.

BTW: when using the command docker run -t --rm mattes/boot2docker-vbga cat boot2docker.iso > boot2docker.iso, a correct ISO should be written.

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xiaods commented Aug 27, 2014

How about move to github repo, let everyone can sharing the script.

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ghost commented Sep 8, 2014

This is amazing, thank you for sharing the instructions! Would be nice if moved it to a repo so you can get contributors.

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What about doing this on Windows? How would that work given /Users does not exist on that OS.

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very nice precisely what i need!

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steeef commented Sep 25, 2014

@mattes this is awesome, thank you. Worked like a charm.

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cirpo commented Sep 27, 2014

I downloaded your iso here and I can see that /Users is correctly mounted but my code is on another partition (/Volumes/Sensitive/code).

I tried to mount it with VBoxManage sharedfolder add boot2docker-vm -name code -hostpath /Volumes/Senitive/code but when I run boot2docker ssh I can't find that dir.

What should I do? Create another boot2docker iso with your script and include my shared folder?

Am I missing anything? Thanks a lot.

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cirpo commented Sep 27, 2014

@mattes and it worked! Thanks!

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I just tried this today on a Windows 7 box. I followed the instructions at starting with the "...system replace the old one at ~/.boot2docker/boot2docker.iso". (I downloaded the ISO instead of building my own from

After running the boot2docker init to generate the new virtual machine, I ran the same vboxmanage to add another shared folder from a separate partition:

using cygwin bash shell

ensure the boot2docker VM is not running

boot2docker down

add the expected users partition for Windows system

VBoxManage sharedfolder add boot2docker-vm -name home -hostpath c:/Users

add my other partition

VBoxManage sharedfolder add boot2docker-vm -name -hostpath


VBoxManage sharedfolder add boot2docker-vm -name dockshare -hostpath f:/docker/

restart the boot2docker VM

boot2docker up

log in

boot2docker ssh

verify original users mapped

ls -alF /Users

the fun stuff, adding the second path in NON-PERSISTENT mode

sudo modprobe vboxsf && sudo mkdir / && sudo mount -t vboxsf /


sudo modprobe vboxsf && sudo mkdir /hostshare && sudo mount -t vboxsf dockshare /hostshare

To make a persistent share, you have to modify the dockerfile.tmpl shown above adding the additional shares to this section:

make mount permanent @todo it works, but its ugly. where should this go?

RUN echo '#!/bin/sh' >> $ROOTFS/etc/rc.d/vbox-guest-additions-permanent-mount;
echo 'sudo modprobe vboxsf && sudo mkdir /Users && sudo mount -t vboxsf home /Users' >> $ROOTFS/etc/rc.d/vbox-guest-additions-permanent-mount;
echo 'sudo modprobe vboxsf && sudo mkdir / && sudo mount -t vboxsf /' >> $ROOTFS/etc/rc.d/vbox-guest-additions-permanent-mount

Rerun the build script to create the ISO file and run the steps again starting with the replace current ISO after stopping the B2D VM

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It works for me! I had to add the -y option to the 7z command for some reason "7z x -y ...", and then to recover from the error had to remove the mkdir commands.

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