Posts tagged with “Vagrant” on Mark van Lent’s weblog

Custom Kali Linux ISO — part 2

2024-02-13T20:03:46Z

In part 1 of this (mini) series I described what I did to be able to build an ISO image using Vagrant. Now it’s time to actually customize it.

I’ll show what I have done and will provide links to the official documentation for more in-depth information. This post is mainly for my own reference in the future, but others might benefit from it as wel.

The basis is an existing Kali Linux environment which is setup with the build script. See the Getting Ready section of the documentation. Long story short:

sudo apt install -y git live-build simple-cdd cdebootstrap curl
git clone https://gitlab.com/kalilinux/build-scripts/live-build-config.git
cd live-build-config

Additional packages

You can include extra packages on your custom Live ISO. If these are available in the Kali repos, it is quite simple. As described in the documentation you can edit the files (in case of the default Live ISO) in kali-config/variant-default/package-lists/kali.list.chroot. I decided to put the additional packages in a new file:

echo "# Custom packages
chromium
torbrowser-launcher
" > kali-config/variant-default/package-lists/custom.list.chroot

Additional APT repositories

A bit harder was the case where I wanted to add Visual Studio Code. This package requires a separate APT repository. So let’s start there first.

To be able to add the files needed, you need to create an additional directory:

mkdir -p kali-config/common/archives

Now you can configure the repository:

echo "deb [arch=amd64] https://packages.microsoft.com/repos/vscode stable main" > kali-config/common/archives/vscode.list.chroot
cp kali-config/common/archives/vscode.list.chroot kali-config/common/archives/vscode.list.binary

The first command creates a file with the .chroot extension and is used during the chroot stage. To also have this file on the live system (to be able to use APT later on to update the packages), I copy the .chroot file to one ending in .binary. For more information on this subject, see the Debian documentation pages Customization overview and Customizing package installation.

The APT repository signing key also needs to be stored in the same directory:

curl -s -o kali-config/common/archives/vscode.key https://packages.microsoft.com/keys/microsoft.asc

There’s one more change that needs to be made. To make sure the build process can actually use the packages from the added repository, you’ll need to include a few more packages at boot time.

To do this, edit the file auto/config and add an --include option to the debootstrap-options line. Concretely this means changing this line:

--debootstrap-options "--keyring=/usr/share/keyrings/kali-archive-keyring.gpg" \

into this:

--debootstrap-options "--include=apt-transport-https,ca-certificates,openssl --keyring=/usr/share/keyrings/kali-archive-keyring.gpg" \

After that you are good to go. Just do not forget to add the package you want to install (in this case code) to the list of packages. In my case this meant updating kali-config/variant-default/package-lists/custom.list.chroot.

Custom Kali Linux ISO — part 1

2024-02-13T20:03:46Z

When I wanted to create a custom Kali Linux ISO using Vagrant, the allocated disk was not big enough. Solving this required some searching and putting several bits of information together. This post shows how I increased the disk size.

The Kali documentation contains a nice page about creating a custom Kali ISO. That page states that [i]deally, you should build your custom Kali ISO from within a pre-existing Kali environment, […] so I decided to use Vagrant to create a virtual machine which I could use.

The basic configuration for that box:

Vagrant.configure("2") do |config|
  config.vm.box = "kalilinux/rolling"

  config.vm.provider "virtualbox" do |vb|
    # Do not display the VirtualBox GUI when booting the machine
    vb.gui = false
  end
end

When I started building the ISO, the default 40G disk filled up and the process could not be completed.

To solve this, the first step was to have Vagrant resize the disk for the machine. You can do this by adding a single line to your configuration. (For details see the relevant Vagrant documentation.)

Vagrant.configure("2") do |config|
  config.vm.box = "kalilinux/rolling"
  config.vm.disk :disk, size: "50GB", primary: true

  config.vm.provider "virtualbox" do |vb|
    # Do not display the VirtualBox GUI when booting the machine
    vb.gui = false
  end
end

While this increases the size of the disk, I still had to increase the partition in the OS. This was a bit more involved, but by adding a couple of commands in a config.vm.provision section, I got it working without needing to reboot the machine afterwards:

Vagrant.configure("2") do |config|
  config.vm.box = "kalilinux/rolling"
  config.vm.disk :disk, size: "50GB", primary: true

  config.vm.provider "virtualbox" do |vb|
    # Do not display the VirtualBox GUI when booting the machine
    vb.gui = false
  end
  config.vm.provision "shell", inline: <<-SHELL
    apt-get update
    apt-get install -y cloud-guest-utils
    swapoff -a
    echo '+10G,' | sfdisk --move-data --force /dev/sda -N 2
    partprobe
    growpart /dev/sda 1
    resize2fs /dev/sda1
    swapon -a
  SHELL
end

Running “vagrant up” now does all the heavy lifting for you. Do note that resizing the disk and making the extra space available to the OS takes significantly more time when creating the machine (compared to using a machine with the default disk size). Then again: if you know this, you can plan to have a cup of coffee (or tea if you are like me) in that time.

The end result:

┌──(vagrant㉿kali)-[~]
└─$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            942M     0  942M   0% /dev
tmpfs           197M  896K  196M   1% /run
/dev/sda1        48G   14G   32G  31% /
tmpfs           983M     0  983M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           197M  116K  197M   1% /run/user/126
vagrant         232G  173G   59G  75% /vagrant
tmpfs           197M  112K  197M   1% /run/user/1000

Time to create a custom Kali ISO… See part 2 for how I added extra packages to the ISO.

How to create a custom Vagrant box

2021-09-24T11:41:49Z

This is a description of how I created a custom Vagrant box starting from a Lubuntu 14.04 desktop CD.

This post is based on the instructions that were published by Angel Ruiz in his article Steps to create a Vagrant Base Box with Ubuntu 14.04 Desktop (GUI) and VirtualBox. By publishing my version here, it is easier for me to reproduce this if I want to create a new version.

I’m assuming that VirtualBox and Vagrant are already installed.

Create a virtual machine

First I downloaded the correct ISO, in this case “Lubuntu 14.04.1 Desktop AMD64”, and used this to create a new virtual machine in VirtualBox. During the installation process I made sure that the user name is “vagrant”.

After the installation was done and I rebooted, I made sure the system was up-to-date. To save some disk space, I removed the original kernel (3.13.0-32) and rebooted so the updated kernel was used (3.13.0-43).

$ sudo apt-get update && sudo apt-get dist-upgrade -y
$ sudo apt-get purge -y linux-image-3.13.0-32-generic linux-image-extra-3.13.0-32-generic linux-headers-3.13.0-32 linux-headers-3.13.0-32-generic
$ sudo shutdown -r now

Make the machine ‘vagrant compatible’

A basic setup is needed for Vagrant to function.

Passwordless “sudo” command

Vagrant expects the default SSH user to have passwordless sudo configured.

$ sudo su -
$ export EDITOR=vi  # my personal preference over nano
$ visudo

This allowed me to add this line:

vagrant ALL=(ALL) NOPASSWD:ALL

Back to the vagrant user.

$ exit

SSH

Vagrant needs to be able to SSH into the machine. So I installed an SSH server.

$ sudo apt-get install -y openssh-server

By default the SSH server runs on port 22 and allows login with a public key (due to the line “PubkeyAuthentication yes” in /etc/ssh/sshd_config). So I did not have to change anything there.

I added the Vagrant SSH keypair to the authorised keys of the vagrant user.

$ mkdir -p /home/vagrant/.ssh
$ wget --no-check-certificate https://raw.github.com/mitchellh/vagrant/master/keys/vagrant.pub -O /home/vagrant/.ssh/authorized_keys
$ chmod 0700 /home/vagrant/.ssh
$ chmod 0600 /home/vagrant/.ssh/authorized_keys
$ chown -R vagrant /home/vagrant/.ssh

Guest Additions

To use shared folders I needed to install the Guest Additions. But first a bit of preparation was needed.

$ sudo apt-get install -y dkms build-essential linux-headers-generic

Now I could install the Guest Additions.

After mounting the ISO, I manually started the installation.

$ sudo /media/vagrant/VBOXADDITIONS_4.3.20_96996/autorun.sh
$ sudo umount /media/vagrant/VBOXADDITIONS_4.3.20_96996

Puppet

Since I’ll be configuring the Vagrant boxes using Puppet, I also installed Puppet.

$ sudo apt-get install -y puppet-common

Cleanup

To make the image a little smaller, I removed a couple of packages I usually won’t need anyway.

$ sudo apt-get purge -y abiword* gnumeric* build-essential cpp-4.8 g++-4.8 libc-dev libc6-dev libgcc-4.8-dev make linux-libc-dev dpkg-dev
$ sudo apt-get autoclean && sudo apt-get clean

There were probably more packages I could have removed to get to a minimum, but this was enough for me.

To get a list of the installed packages and their size, I used this command (thanks to user “raspi” over at commandlinefu.com):

$ dpkg-query -Wf '${Installed-Size}\t${Package}\n' | sort -n

Next item on the list: reduce the size of the .vdi file by making sure all the free space only has zeros and then compacting the file.

On the guest:

$ sudo dd if=/dev/zero of=/ZEROS bs=1M
$ sudo rm /ZEROS
$ sudo shutdown -h now

On the host:

$ vboxmanage modifyhd "/home/mark/VirtualBox VMs/lubuntu 14.04 desktop amd64/lubuntu 14.04 desktop amd64.vdi" --compact

This resulted in a reduction from 4.1GB to 2.7GB.

Package the box

Although you can argue whether the current virtual machine is a “bare minimum required for Vagrant”, it’ll do for my purposes. So it was time to package it.

Since this is a box where I’ll want the GUI by default, I created a Vagrantfile:

Vagrant.configure("2") do |config|
  config.vm.provider "virtualbox" do |vb|
    # Don't boot with headless mode
    vb.gui = true
  end
end

(By including this file in the box, see the next command, this little piece of configuration is loaded when the box is used. It will be first in the load order.)

Then I executed the following commands:

$ vagrant package --base "lubuntu 14.04 desktop amd64" --vagrantfile Vagrantfile
$ vagrant box add lubuntu-14.04-desktop-amd64 package.box

The first command creates a package.box file from the virtual machine called “lubuntu 14.04 desktop amd64”. This file is then used in the second command. The new base box “lubuntu-14.04-desktop-amd64” is now available for use.

Use the box

To use the custom base box, you have to initialise a Vagrant environment by creating an initial Vagrantfile, just as normal.

$ vagrant init lubuntu-14.04-desktop-amd64

The last step:

$ vagrant up

(Note that I edited the final Vagrantfile in the project directory to use the Puppet provisioner. But that is beyond the scope of this article.)

More information

As I stated earlier, this is mostly a mix of information that is already online elsewhere, e.g.:

aruizca’s blog: Steps to create a Vagrant Base Box with Ubuntu 14.04 Desktop (GUI) and VirtualBox
Vagrant docs: Generic guide to creating a base box
Vagrant docs: VirtualBox specific guide to creating a base box

Failed to mount folders?

Initially I had the virtualbox package installed on my Ubuntu host and used this to create my virtual machine. However, when I started the virtual machine with Vagrant, I got the following error:

Failed to mount folders in Linux guest. This is usually because
the "vboxsf" file system is not available. Please verify that
the guest additions are properly installed in the guest and
can work properly. The command attempted was:

mount -t vboxsf -o uid=`id -u vagrant`,gid=`getent group vagrant | cut -d: -f3` /vagrant /vagrant
mount -t vboxsf -o uid=`id -u vagrant`,gid=`id -g vagrant` /vagrant /vagrant

Apparently this problem with shared folders is a known issue. It should be solved in version 4.3.12, but Ubuntu 14.04 ships with VirtualBox version 4.3.10. And unfortunately the workaround listed in the issue (creating a symlink) did not work for me.

For me the easiest solution seemed to be to add a new package repository to my host machine (see the page Download VirtualBox for Linux Hosts) and install the virtualbox-4.3 package, which provides version 4.3.20 (at the time of writing). After creating a new base box with this version of VirtualBox, Vagrant could mount the shared folders properly.