code-server/doc/security/ssl.md

Generate a Self-signed Certificate 🔒

code-server has the ability to secure your connection between client and server using SSL/TSL certificates. By default, the server will start with an unencrypted connection. We recommend Self-signed TLS/SSL certificates for personal use of code-server or within an organization.

This guide will show you how to create a self-signed certificate and start code-server using your certificate/key.

TLS / HTTPS

You can specify any location that you want to save the certificate and key. In this example, we will navigate to the root directory, create a folder called certs and cd into it.

mkdir ~/certs && cd ~/certs

If you don't already have a TLS certificate and key, you can generate them with the command below. They will be placed in ~/certs.

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ~/certs/MyKey.key -out ~/certs/MyCertificate.crt

You will be prompted to add some identifying information about your organization:

You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:US
State or Province Name (full name) [Some-State]:TX
Locality Name (eg, city) []:Austin
Organization Name (eg, company) [Coder Technologies]:Coder
Organizational Unit Name (eg, section) []:Docs
Common Name (e.g. server FQDN or YOUR name) []:hostname.example.com
Email Address []:admin@example.com

If you already have a TLS certificate and key, you can simply reference them in the --cert and --cert-key flags when launching code-server.

Starting code-server with a Certificate and Key

Just add the --cert and --cert-key flags when you run code-server:

./code-server --cert=~/certs/MyCertificate.crt --cert-key=~/certs/MyKey.key

You should check that the WARN No certificate specified. This could be insecure are no longer visible in the output.

Other Options

For larger organizations you may wish to rely on a trusted Certificate Authority as opposed to a self-signed certificate. For more information on generating free and open certificates for your site, please check out EFF's certbot. Certbot is a cli to generate certificates using LetsEncrypt.