Table of Contents
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.
Certbot is packaged for many common operating systems and web servers. Check whether
letsencrypt) is packaged for your web server’s OS by visiting
certbot.eff.org, where you will also find the correct installation instructions for
Unless you have very specific requirements, we kindly suggest that you use the Certbot packages provided by your package manager (see certbot.eff.org). If such packages are not available, we recommend using
certbot-auto, which automates the process of installing Certbot on your system.
Certbot currently requires Python 2.7 or 3.4+ running on a UNIX-like operating
system. By default, it requires root access in order to write to
bind to port 80 (if you use the
standalone plugin) and to read and
modify webserver configurations (if you use the
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, Fedora, SUSE, Gentoo and Darwin.
Additional integrity verification of certbot-auto script can be done by verifying its digital signature. This requires a local installation of gpg2, which comes packaged in many Linux distributions under name gnupg or gnupg2.
certbot-auto requires 512MB of RAM in order to build some
of the dependencies. Installing from pre-built OS packages avoids this
requirement. You can also temporarily set a swap file. See “Problems with
Python virtual environment” below for details.
If you are offline or your operating system doesn’t provide a package, you can use
an alternate method for installing
certbot-auto wrapper script installs Certbot, obtaining some dependencies
from your web server OS and putting others in a python virtual environment. You can
download and run it as follows:
user@webserver:~$ wget https://dl.eff.org/certbot-auto user@webserver:~$ chmod a+x ./certbot-auto user@webserver:~$ ./certbot-auto --help
To check the integrity of the
you can use these steps:
user@webserver:~$ wget -N https://dl.eff.org/certbot-auto.asc user@webserver:~$ gpg2 --keyserver pool.sks-keyservers.net --recv-key A2CFB51FA275A7286234E7B24D17C995CD9775F2 user@webserver:~$ gpg2 --trusted-key 4D17C995CD9775F2 --verify certbot-auto.asc certbot-auto
The output of the last command should look something like:
gpg: Signature made Wed 02 May 2018 05:29:12 AM IST gpg: using RSA key A2CFB51FA275A7286234E7B24D17C995CD9775F2 gpg: key 4D17C995CD9775F2 marked as ultimately trusted gpg: checking the trustdb gpg: marginals needed: 3 completes needed: 1 trust model: pgp gpg: depth: 0 valid: 2 signed: 2 trust: 0-, 0q, 0n, 0m, 0f, 2u gpg: depth: 1 valid: 2 signed: 0 trust: 2-, 0q, 0n, 0m, 0f, 0u gpg: next trustdb check due at 2027-11-22 gpg: Good signature from "Let's Encrypt Client Team <firstname.lastname@example.org>" [ultimate]
certbot-auto command updates to the latest client release automatically.
certbot-auto is a wrapper to
certbot, it accepts exactly
the same command line flags and arguments. For more information, see
Certbot command-line options.
For full command line help, you can type:
./certbot-auto --help all
On a low memory system such as VPS with less than 512MB of RAM, the required dependencies of Certbot will 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
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 operating system packages (see instructions at
certbot.eff.org) or, as a fallback,
certbot-auto. 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 certs manually. Our ciphersuites page provides some information about recommended ciphersuites. If none of these make much sense to you, you should definitely use the certbot-auto method, 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
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,
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. If you would like to obtain a wildcard certificate from
Let’s Encrypt’s ACMEv2 server, you’ll need to include
https://acme-v02.api.letsencrypt.org/directory on the command line as
For more information about the layout
/etc/letsencrypt directory, see Where are my certificates?.
sudo pacman -S certbot
If you run Debian Stretch or Debian Sid, you can install certbot packages.
sudo apt-get update sudo apt-get install certbot python-certbot-apache
If you don’t want to use the Apache plugin, you can omit the
python-certbot-apache package. Or you can install
Packages exist for Debian Jessie via backports. First you’ll have to follow the instructions at http://backports.debian.org/Instructions/ to enable the Jessie backports repo, if you have not already done so. Then run:
sudo apt-get install certbot python-certbot-apache -t jessie-backports
sudo dnf install certbot python2-certbot-apache
cd /usr/ports/security/py-certbot && make install clean
pkg install py27-certbot
The official Certbot client is available in Gentoo Portage. If you want to use the Apache plugin, it has to be installed separately:
emerge -av app-crypt/certbot emerge -av app-crypt/certbot-apache
When using the Apache plugin, you will run into a “cannot find an
SSLCertificateFile directive” or “cannot find an SSLCertificateKeyFile
directive for certificate” error if you’re sporting the default Gentoo
httpd.conf. You can fix this by commenting out two lines in
/etc/apache2/httpd.conf as follows:
<IfDefine SSL> LoadModule ssl_module modules/mod_ssl.so </IfDefine>
#<IfDefine SSL> LoadModule ssl_module modules/mod_ssl.so #</IfDefine>
For the time being, this is the only way for the Apache plugin to recognise the appropriate directives when installing the certificate. Note: this change is not required for the other plugins.
- Build from source:
cd /usr/pkgsrc/security/py-certbot && make install clean
- Install pre-compiled package:
cd /usr/ports/security/letsencrypt/client && make install clean
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.
Installation from source is only supported for developers and the whole process is described in the Developer Guide.
Please do not use
python setup.py install,
install ., or
easy_install .. Please do not attempt the
installation commands as superuser/root and/or without virtual environment,
sudo python setup.py install,
sudo pip install,
./venv/bin/.... These modes of operation might corrupt your operating
system and are not supported by the Certbot team!