DEV Community

Aaron Peschel
Aaron Peschel

Posted on

Compiling OpenVPN in an Ubuntu 14.04 Chroot

#ubuntu #openvpn #buildtools #linux

Originally published by apeschel on July 11, 2016, 6:35 p.m.

Set up chroot build environment

Digital Ocean has a good guide for setting up a build chroot available here:

https://www.digitalocean.com/community/tutorials/how-to-configure-chroot-environments-for-testing-on-an-ubuntu-12-04-vps

The only thing of note is that they recommend putting your chroot in your root / directory on your base host. I suggest using /srv/schroot/ instead.

The instructions provided here are for Ubuntu trusty, which is what we will be using to build OpenVPN.

sudo apt-get update sudo apt-get install dchroot debootstrap
Enter fullscreen mode Exit fullscreen mode 
sudo mkdir -p /srv/schroot/ubuntu14.04
Enter fullscreen mode Exit fullscreen mode 
sudo debootstrap --variant=buildd --arch amd64 trusty /srv/schroot/ubuntu14.04/ http://us.archive.ubuntu.com/ubuntu/
Enter fullscreen mode Exit fullscreen mode 
proc /srv/schroot/ubuntu14.04/proc proc defaults 0 0 sysfs /srv/schroot/ubuntu14.04/sys sysfs defaults 0 0
Enter fullscreen mode Exit fullscreen mode 
sudo mount proc /srv/schroot/ubuntu14.04/proc -t proc sudo mount sysfs /srv/schroot/ubuntu14.04/sys -t sysfs
Enter fullscreen mode Exit fullscreen mode 
sudo cp /etc/hosts /srv/schroot/ubuntu14.04/etc/hosts
Enter fullscreen mode Exit fullscreen mode 
sudo chroot /srv/schroot/ubuntu14.04/ /bin/bash
Enter fullscreen mode Exit fullscreen mode

Set Up Build Environment

https://community.openvpn.net/openvpn/wiki/TesterDocumentation http://packaging.ubuntu.com/html/

Having a text editor in our chroot environment will reduce the number of times we have to leave and enter the chroot, thus it is installed for convenience.

apt-get install vim
Enter fullscreen mode Exit fullscreen mode

Our chroot environment will have a very bare-bones sources.list. We will need to add some entries to it.

vim /etc/apt/sources.list
Enter fullscreen mode Exit fullscreen mode

Add the following text.

deb-src http://us.archive.ubuntu.com/ubuntu trusty main deb http://us.archive.ubuntu.com/ubuntu trusty universe deb-src http://us.archive.ubuntu.com/ubuntu trusty universe
Enter fullscreen mode Exit fullscreen mode

We need to update Ubuntu's policy-rc.d to let it know that we are in a chroot environment.

vim /usr/sbin/policy-rc.d
Enter fullscreen mode Exit fullscreen mode

Add the following to the file

#!/bin/sh exit 101
Enter fullscreen mode Exit fullscreen mode

Now we will install any additional build tools that will be required. We will use bzr (bazzar) to build the OpenVPN package.

cd $HOME locale-gen en_US.UTF-8 apt-get update apt-get install net-tools autoconf libtool dialog apt-get install bzr bzr-builddeb devscripts
Enter fullscreen mode Exit fullscreen mode

Build OpenVPN 

apt-get build-dep openvpn
Enter fullscreen mode Exit fullscreen mode

Using Canonical Bazaar

Here we download the 14.04 OpenVPN source in a new package branch.

cd $HOME bzr branch lp:ubuntu/trusty/openvpn
Enter fullscreen mode Exit fullscreen mode

The TLS keys that are used for the OpenVPN tests in the 14.04 source have expired. This will cause the tests to fail. We can use the keys from the latest OpenVPN release instead to fix this.

apt-get install git git clone git://git.code.sf.net/p/openvpn/openvpn-testing openvpn-openvpn-testing cp openvpn-openvpn-testing/sample/sample-keys/* openvpn/sample/sample-keys/
Enter fullscreen mode Exit fullscreen mode

Now to finally build the OpenVPN package.

cd $HOME cd openvpn bzr bd -- -b -us -uc
Enter fullscreen mode Exit fullscreen mode

Build Raw binaries using make

This will skip the testing phase, which takes a long time with the OpenVPN package. However, it will not create a package and will require installation via make install

cd $HOME apt-get source openvpn cd openvpn-* autoreconf -vi ./configure make all make check
Enter fullscreen mode Exit fullscreen mode

Build openvpn-auth-ldap

This follows the same core process as building the OpenVPN package.

apt-get build-dep openvpn-auth-ldap
Enter fullscreen mode Exit fullscreen mode

Using Canonical Bazaar 

cd $HOME bzr branch lp:ubuntu/trusty/openvpn-auth-ldap cd openvpn-auth-ldap bzr bd -- -b -us -uc
Enter fullscreen mode Exit fullscreen mode

Using Make 

cd $HOME apt-get source openvpn-auth-ldap cd openvpn-auth-ldap-* ./configure make
Enter fullscreen mode Exit fullscreen mode

Top comments (0)