1. Introduction

Vagrant is a virtual machine management program that makes it trivial to build
and configure reproducible virtual machines. Wireshark's source code includes
a Vagrantfile which can be used to set up a complete development environments
in a virtual machine, including all necessary compilers, dependent libraries,
and tools like valgrind.

Using vagrant can greatly simplify the creation of a Linux build environment
for new developers, at the cost of running your builds in a virtual machine,
thus with reduced performance.

2. Installation

The Vagrantfile included in Wireshark's source directory is configured to use
VirtualBox as the backing virtual machine technology provider. You must first
install VirtualBox from https://www.virtualbox.org/.

Now install vagrant itself from https://www.vagrantup.com/.

Please note that vagrant is a CLI command and should typically be installed in
your host system's $PATH. To better understand what vagrant is doing you may
want to review vagrant's `Getting Started` web pages.

3. Setup

By default vagrant looks for the file name Vagrantfile in the current
directory. Wireshark's Vagrantfile is located in the root of the Wireshark
source folder.

Once both VirtualBox and vagrant are installed, setting up an Ubuntu Wireshark
development VM is as simple as running `vagrant up ubuntu`.

The first time that the `vagrant up` command is executed vagrant will initiate
the download of a specific VM image (what they call a box) from HashiCorp's
Atlas box catalog. Once the box is downloaded a VM will be instantiated and
powered-on.

Use the command `vagrant status` to determine the state of the VMs.

The command `vagrant provision` will run any provisioning tasks defined in the
Vagrantfile. Wireshark's Vagrantfile is configured to provision the machine
and build the project using vagrant_build.sh.

The vagrant_build.sh script sets up a cmake
build environment which includes creating a ~/build folder initialized for an
out-of-tree cmake build and then triggering a build.

4. Usage

Running `vagrant ssh ubuntu` from the Wireshark source directory will log you
into Ubuntu VM as the userid vagrant.

The Ubuntu VM's build folder is located in ~/build. The Ubuntu VM's source
folder is actually the source folder from the host system mounted as
/home/vagrant/wireshark. Any changes made in the VM's ~/wireshark folder are
reflected in the host system's Wireshark source folder and vice-versa.

Installing the vagrant-vbguest plugin is strongly recommended to get synced
folders working on all boxes and other niceties. You can install it with the
command `vagrant plugin install vagrant-vbguest`.

Once logged into the VM issue the command `cd ~/build` followed by `make` to
trigger a new wireshark build based on whatever is in your host system's source
tree (the VM's ~/wireshark folder).

The various Wireshark applications can be run from the ~/build folder of the
VM with commands such as `./run/wireshark`, `./run/tshark`, etc.

To run the Wireshark GUI you will need an X server and the X authority file
utility (xauth) installed in the guest. For Ubuntu use `apt-get install xauth`,
Fedora use `dnf install xorg-x11-xauth`.

If you are using macOS ({Mac} OS X) as the host system then you would likely
use XQuartz as your X server. XQuartz can be downloaded from
https://www.xquartz.org/.

The VM can be shutdown or suspended from the host system with the
commands `vagrant halt` and `vagrant suspend` respectively. In either case the
VM can be brought back up with the command `vagrant up`.

5. Using Vagrant with multiple VMs
Wireshark's Vagrantfile is configured with more than one box so most vagrant
commands, those that apply to machines, need to be provided with the machine
name. You can list all machines and their state with the `vagrant status`
command.
