Let's Encrypt test server (Boulder)


I developed a pretty nice concrete5 plugin to integrate Let’s Encrypt (free SSL/HTTPS certificates) in concrete5 5.7+.

When I developed that plugin, no other PHP library existed, so I had to do a lot of research and tests.
That’s why I needed a local server that could act exactly as the official Let’s Encrypt server.

Luckily, the brave guys at Let’s Encrypt are gifting the world Boulder, that is the engine that resides behind their services.

In this article I’ll explain you how I set up a local Boulder server, allowing you to test Let’s Encrypt clients.

For simplicity, in this document I assume that you will run the client and a test website on your physical computer.

Configure the host names

Let’s assume you want to test your Let’s Encrypt client agains two domain called www.example.com and www.test.com.
First of all, you need to tell your computer that those domains reside on your computer.

This can be done by modifying the /etc/hosts file (for Linux and Mac OS X) or the file C:\Windows\System32\drivers\etc\hosts (for Windows), by adding these two lines: www.example.com www.test.com

You need to tell your system that the boulder too resides in your computer: boulder

Setup Boulder

Linux and Mac OS X

On Linux and Mac OS X you have to install Docker.

Then you can download the latest Boulder release from GitHub.

Unzip that archive and in a terminal window type in:

cd path/to/extracted/archive

After a couple of minutes, you’ll have a local Boulder instance up and running.


On Windows you’ll need a bit more work to start Boulder.

First of all, download and install VirtualBox.

Create a new virtual machine with Ubuntu Server 16.04. When installing Ubuntu, you’ll be asked which optional components you want to install: choose standard system utilities and OpenSSH server.

Once Ubuntu is installed, you have to go to the virtual machine settings > Network > Advanced > Port Forwarding and add these new rules:

Name Protocol Host IP Host Port Guest IP Guest Port
Boulder TCP   4000   4000
DB TCP   23306   3306
SSH TCP   20022   22

The Boulder rule is required in order to be able to let your client communicate with Boulder.
The DB rule is required if you want to access the Boulder database from outside the VirtualMachine.
The SSH rule is really helpful since it allows you to connect to the virtual machine via SSH with PuTTY (connect to via port 20022).
I usually create a link to open a SSH shell with a single click (example: putty.exe -ssh -pw UBUNTU_PASSWORD UBUNTU_USERNAME@ -P 20022).

Once Ubuntu is installed, you have to install the VirtualBox Guest additions and Docker:

  • From the virtual machine Devices menu, choose Insert Guest additions CD image...
  • open a new SSH session with PuTTY and type the following commands:

    # Update the system
    sudo apt-get update
    sudo apt-get upgrade -y
    # Install the packages required for the VirtualBox Guest additions and Docker
    sudo apt-get install -y build-essential module-assistant linux-headers-`uname -r` \
      apt-transport-https ca-certificates linux-image-extra-`uname -r` unzip \
    # Install the VirtualBox Guest additions
    sudo mount /dev/cdrom /media/cdrom
    sudo /media/cdrom/VBoxLinuxAdditions.run
    sudo umount /media/cdrom
    sudo adduser `whoami` vboxsf
    # Install Docker
    sudo apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 \
        --recv-keys 58118E89F3A912897C070ADBF76221572C52609D
    echo 'deb https://apt.dockerproject.org/repo ubuntu-xenial main' | sudo tee /etc/apt/sources.list.d/docker.list
    sudo apt-get update
    sudo apt-get install -y --allow-unauthenticated docker-engine docker-compose
    # Allow running Docker without sudo
    sudo groupadd docker
    sudo usermod -aG docker `whoami`
    # Start Docker on boot
    sudo systemctl enable docker
    # Download Builder
    mkdir -p ~/boulder/src/github.com/letsencrypt
    wget --show-progress -q -O ~/boulder-release.zip https://github.com/letsencrypt/boulder/archive/release.zip
    unzip -q -d ~ ~/boulder-release.zip
    mv ~/boulder-release ~/boulder/src/github.com/letsencrypt/boulder
    rm boulder-release.zip
    # Configure the FAKE_DNS
    cat ~/boulder/src/github.com/letsencrypt/boulder/docker-compose.yml | sed -e 's/FAKE_DNS: '`netstat -rn | grep UG | cut -f10 -d" "`'/' >~/boulder/src/github.com/letsencrypt/boulder/docker-compose.yml
    printf '#!/bin/bash\n\nexport GOPATH='$HOME'/boulder\ncd '$HOME'/boulder/src/github.com/letsencrypt/boulder\ndocker-compose up' >~/boulder.sh
    chmod a+x ~/boulder.sh
    # Shutdow the virtual machine
    sudo shutdown -P now

At the end, the virtual machine will be powered off.
You can restart it in headless mode: you won’t see any virtual machine window, but you’ll be able to connect to it via the comfortable PuTTY/SSH interface.

To start boulder, you simply have to type this command via SSH:


Website port

By default, Boulder will try to reach your website via port 5002 (for http) and optionally via port 5001 (for https).
If your local website is available at another port, you should change the file test/config/va.json under the main Boulder folder.

In particular, you may want to change the values of the httpPort and/or httpsPort options (under portConfig).
So, if for instance your local website is available via HTTP at port 1000, you should have

"httpPort": 1000,

If you change the boulder configuration, you should restart boulder.

First of all, stop all the containers listed by the command docker ps (for instance: docker stop c0ea10c55ddd), then restart boulder as described above.

Next, you may want to delete the created containers listed by the command docker ps -a (for instance: docker rm c0ea10c55ddd)

Accessing the database

You can access the Docker MySQL/MariaDB database by connecting to the 3306 port of the IP address of the boulder-mysql container.

This can be done with a command like this:

mysql -u root --password= -h `docker inspect -f '{{.NetworkSettings.IPAddress }}' boulder-mysql`

If you are running Boulder inside a virtual machine, you can expose it with iptables, by running this command:

sudo iptables -t nat -A DOCKER -p tcp --dport 3306 -j DNAT --to-destination `docker inspect -f '{{.NetworkSettings.IPAddress }}' boulder-mysql`:3306