Get Certbot¶

Table of Contents

About Certbot
System Requirements
Alternate installation methods

About Certbot ¶

Certbot is meant to be run directly on a web server, normally by a system administrator. In most cases, running Certbot on your personal computer is not a useful option. The instructions below relate to installing and running Certbot on a server.

System administrators can use Certbot directly to request certificates; they should not allow unprivileged users to run arbitrary Certbot commands as root, because Certbot allows its user to specify arbitrary file locations and run arbitrary scripts.

Certbot is packaged for many common operating systems and web servers. Check whether certbot (or letsencrypt) is packaged for your web server’s OS by visiting certbot.eff.org, where you will also find the correct installation instructions for your system.

Note

Unless you have very specific requirements, we kindly suggest that you use the installation instructions for your system found at certbot.eff.org.

System Requirements ¶

Certbot currently requires Python 3.6+ running on a UNIX-like operating system. By default, it requires root access in order to write to /etc/letsencrypt, /var/log/letsencrypt, /var/lib/letsencrypt; to bind to port 80 (if you use the standalone plugin) and to read and modify webserver configurations (if you use the apache or nginx plugins). If none of these apply to you, it is theoretically possible to run without root privileges, but for most users who want to avoid running an ACME client as root, either letsencrypt-nosudo or simp_le are more appropriate choices.

The Apache plugin currently requires an OS with augeas version 1.0; currently it supports modern OSes based on Debian, Ubuntu, Fedora, SUSE, Gentoo and Darwin.

Alternate installation methods ¶

If you are offline or your operating system doesn’t provide a package, you can use an alternate method for installing certbot.

Snap ¶

Most modern Linux distributions (basically any that use systemd) can install Certbot packaged as a snap. Snaps are available for x86_64, ARMv7 and ARMv8 architectures. The Certbot snap provides an easy way to ensure you have the latest version of Certbot with features like automated certificate renewal preconfigured.

You can find instructions for installing the Certbot snap at https://certbot.eff.org/instructions by selecting your server software and then choosing “snapd” in the “System” dropdown menu. (You should select “snapd” regardless of your operating system, as our instructions are the same across all systems.)

Running with Docker ¶

Docker is an amazingly simple and quick way to obtain a certificate. However, this mode of operation is unable to install certificates or configure your webserver, because our installer plugins cannot reach your webserver from inside the Docker container.

Most users should use the instructions at certbot.eff.org. You should only use Docker if you are sure you know what you are doing and have a good reason to do so.

You should definitely read the Where are my certificates? section, in order to know how to manage the certificates manually. Our ciphersuites page provides some information about recommended ciphersuites. If none of these make much sense to you, you should definitely use the installation method recommended for your system at certbot.eff.org, which enables you to use installer plugins that cover both of those hard topics.

If you’re still not convinced and have decided to use this method, from the server that the domain you’re requesting a certficate for resolves to, install Docker, then issue a command like the one found below. If you are using Certbot with the Standalone plugin, you will need to make the port it uses accessible from outside of the container by including something like -p 80:80 or -p 443:443 on the command line before certbot/certbot.

sudo docker run -it --rm --name certbot \
            -v "/etc/letsencrypt:/etc/letsencrypt" \
            -v "/var/lib/letsencrypt:/var/lib/letsencrypt" \
            certbot/certbot certonly

Running Certbot with the certonly command will obtain a certificate and place it in the directory /etc/letsencrypt/live on your system. Because Certonly cannot install the certificate from within Docker, you must install the certificate manually according to the procedure recommended by the provider of your webserver.

There are also Docker images for each of Certbot’s DNS plugins available at https://hub.docker.com/u/certbot which automate doing domain validation over DNS for popular providers. To use one, just replace certbot/certbot in the command above with the name of the image you want to use. For example, to use Certbot’s plugin for Amazon Route 53, you’d use certbot/dns-route53. You may also need to add flags to Certbot and/or mount additional directories to provide access to your DNS API credentials as specified in the DNS plugin documentation.

For more information about the layout of the /etc/letsencrypt directory, see Where are my certificates?.

Operating System Packages ¶

Warning

While the Certbot team tries to keep the Certbot packages offered by various operating systems working in the most basic sense, due to distribution policies and/or the limited resources of distribution maintainers, Certbot OS packages often have problems that other distribution mechanisms do not. The packages are often old resulting in a lack of bug fixes and features and a worse TLS configuration than is generated by newer versions of Certbot. They also may not configure certificate renewal for you or have all of Certbot’s plugins available. For reasons like these, we recommend most users follow the instructions at https://certbot.eff.org/instructions and OS packages are only documented here as an alternative.

Arch Linux

sudo pacman -S certbot

Debian

If you run Debian Buster or Debian testing/Sid, you can easily install certbot packages through commands like:

sudo apt-get update
sudo apt-get install certbot

If you run Debian Stretch, we recommend you use the packages in Debian backports repository. First you’ll have to follow the instructions at https://backports.debian.org/Instructions/ to enable the Stretch backports repo, if you have not already done so. Then run:

sudo apt-get install certbot -t stretch-backports

In all of these cases, there also packages available to help Certbot integrate with Apache, nginx, or various DNS services. If you are using Apache or nginx, we strongly recommend that you install the python-certbot-apache or python-certbot-nginx package so that Certbot can fully automate HTTPS configuration for your server. A full list of these packages can be found through a command like:

apt search 'python-certbot*'

They can be installed by running the same installation command above but replacing certbot with the name of the desired package.

Ubuntu

If you run Ubuntu, certbot can be installed using:

sudo apt-get install certbot

Optionally to install the Certbot Apache plugin, you can use:

sudo apt-get install python-certbot-apache

Fedora

sudo dnf install certbot python3-certbot-apache

FreeBSD

Port: cd /usr/ports/security/py-certbot && make install clean

Package: pkg install py37-certbot

Gentoo

The official Certbot client is available in Gentoo Portage. From the official Certbot plugins, three of them are also available in Portage. They need to be installed separately if you require their functionality.

emerge -av app-crypt/certbot
emerge -av app-crypt/certbot-apache
emerge -av app-crypt/certbot-nginx
emerge -av app-crypt/certbot-dns-nsone

Note

The app-crypt/certbot-dns-nsone package has a different maintainer than the other packages and can lag behind in version.

NetBSD

Build from source: cd /usr/pkgsrc/security/py-certbot && make install clean

Install pre-compiled package: pkg_add py37-certbot

OpenBSD

Port: cd /usr/ports/security/letsencrypt/client && make install clean

Package: pkg_add letsencrypt

Other Operating Systems

OS packaging is an ongoing effort. If you’d like to package Certbot for your distribution of choice please have a look at the Packaging Guide.

Certbot-Auto ¶

We used to have a shell script named certbot-auto to help people install Certbot on UNIX operating systems, however, this script is no longer supported. If you want to uninstall certbot-auto, you can follow our instructions here.

Problems with Python virtual environment ¶

When using certbot-auto on a low memory system such as VPS with less than 512MB of RAM, the required dependencies of Certbot may fail to build. This can be identified if the pip outputs contains something like internal compiler error: Killed (program cc1). You can workaround this restriction by creating a temporary swapfile:

user@webserver:~$ sudo fallocate -l 1G /tmp/swapfile
user@webserver:~$ sudo chmod 600 /tmp/swapfile
user@webserver:~$ sudo mkswap /tmp/swapfile
user@webserver:~$ sudo swapon /tmp/swapfile

Disable and remove the swapfile once the virtual environment is constructed:

user@webserver:~$ sudo swapoff /tmp/swapfile
user@webserver:~$ sudo rm /tmp/swapfile

Installing from source ¶

Installation from source is only supported for developers and the whole process is described in the Developer Guide.

Warning

Please do not use python certbot/setup.py install, python pip install certbot, or easy_install certbot. Please do not attempt the installation commands as superuser/root and/or without virtual environment, e.g. sudo python certbot/setup.py install, sudo pip install, sudo ./venv/bin/.... These modes of operation might corrupt your operating system and are not supported by the Certbot team!