code-server/doc/guide.md

Setup Guide

• 1. Acquire a remote machine
  • Requirements
  • Google Cloud
• 2. Install code-server
• 3. Expose code-server
  • SSH forwarding
  • Let's Encrypt
  • Self Signed Certificate
  • Change the password?
  • How do I securely access development web services?

This guide demonstrates how to setup and use code-server. To reiterate, code-server lets you run VS Code on a remote server and then access it via a browser.

Further docs are at:

• README.md for a general overview
• FAQ.md for common questions.
• CONTRIBUTING.md for development docs

We'll walk you through acquiring a remote machine to run code-server on and then exposing code-server so you can securely access it.

1. Acquire a remote machine

First, you need a machine to run code-server on. You can use a physical machine you have lying around or use a VM on GCP/AWS.

Requirements

For a good experience, we recommend at least:

• 1 GB of RAM
• 2 cores

You can use whatever linux distribution floats your boat but in this guide we assume Debian on Google Cloud.

Google Cloud

For demonstration purposes, this guide assumes you're using a VM on GCP but you should be able to easily use any machine or VM provider.

You can sign up at https://console.cloud.google.com/getting-started. You'll get a 12 month $300 free trial.

Once you've signed up and created a GCP project, create a new Compute Engine VM Instance.

1. Navigate to Compute Engine -> VM Instances on the sidebar.
2. Now click Create Instance to create a new instance.
3. Name it whatever you want.
4. Choose the region closest to you based on gcping.com.
5. Any zone is fine.
6. We'd recommend a E2 series instance from the General-purpose family.
   • Change the type to custom and set at least 2 cores and 2 GB of ram.
   • Add more vCPUs and memory as you prefer, you can edit after creating the instance as well.
   • https://cloud.google.com/compute/docs/machine-types#general_purpose
7. We highly recommend switching the persistent disk to a SSD of at least 32 GB.
   • Click Change under Boot Disk and change the type to SSD Persistent Disk and the size to 32.
   • You can always grow your disk later.
   • The default OS of Debian 10 is fine.
8. Navigate to Networking -> Network interfaces and edit the existing interface to use a static external IP.
   • Click done to save network interface changes.
9. If you do not have a project wide SSH key, navigate to Security - > SSH Keys and add your public key there.
10. Click create!

Remember, you can shutdown your server when not in use to lower costs. We highly recommend learning to use the gcloud cli to avoid the slow dashboard.

2. Install code-server

SSH into your instance and run the appropriate commands documented in README.md.

Assuming Debian:

curl -fOL https://github.com/cdr/code-server/releases/download/v3.3.1/code-server_3.3.1_amd64.deb
sudo dpkg -i code-server_3.3.1_amd64.deb
systemctl --user enable --now code-server
# Now code-server is running at http://127.0.0.1:8080
# Your password is in ~/.config/code-server/config.yaml

3. Expose code-server

Never, ever expose code-server directly to the internet without some form of authentication and encryption as someone can completely takeover your machine with the terminal.

By default, code-server will enable password authentication which will require you to copy the password from the code-server config file to login. Since it cannot use TLS by default, it will listen on localhost to avoid exposing itself to the world. This is fine for testing but will not work if you want to access code-server from a different machine.

There are several approaches to securely operating and exposing code-server.

tip: You can list the full set of code-server options with code-server --help

SSH forwarding

We highly recommend this approach for not requiring any additional setup, you just need an SSH server on your remote machine. The downside is you won't be able to access code-server without an SSH client like an iPad. If that's important to you, skip to Let's Encrypt.

Recommended reading: https://help.ubuntu.com/community/SSH/OpenSSH/PortForwarding.

First, ssh into your instance and edit your code-server config file to disable password authentication.

# Replaces "auth: password" with "auth: none" in the code-server config.
sed -i.bak 's/auth: password/auth: none/' ~/.config/code-server/config.yaml

Restart code-server with (assuming you followed the guide):

systemctl --user restart code-server

Now forward local port 8080 to 127.0.0.1:8080 on the remote instance.

# -N disables executing a remote shell
ssh -N -L 8080:127.0.0.1:8080 <instance-ip>

Now if you access http://127.0.0.1:8080 locally, you should see code-server!

If you want to make the SSH port forwarding persistent we recommend using mutagen.

# Same as the above SSH command but runs in the background continuously.
# Add `mutagen daemon start` to your ~/.bashrc to start the mutagen daemon when you open a shell.
mutagen forward create --name=code-server tcp:127.0.0.1:8080 <instance-ip>:tcp:127.0.0.1:8080

We also recommend adding the following lines to your ~/.ssh/config to quickly detect bricked SSH connections:

Host *
ServerAliveInterval 5
ExitOnForwardFailure yes

You can also forward your SSH key and GPG agent to the instance to securely access GitHub and sign commits without copying your keys onto the instance.

1. https://developer.github.com/v3/guides/using-ssh-agent-forwarding/
2. https://wiki.gnupg.org/AgentForwarding

Let's Encrypt

Let's Encrypt is a great option if you want to access code-server on an iPad or do not want to use SSH forwarding. This does require that the remote machine is exposed to the internet.

Assuming you have been following the guide, edit your instance and checkmark the allow HTTP/HTTPS traffic options.

1. You'll need to buy a domain name. We recommend Google Domains.
2. Add an A record to your domain with your instance's IP.
3. Install caddy https://caddyserver.com/docs/download#debian-ubuntu-raspbian.

echo "deb [trusted=yes] https://apt.fury.io/caddy/ /" \
    | sudo tee -a /etc/apt/sources.list.d/caddy-fury.list
sudo apt update
sudo apt install caddy

4. Replace /etc/caddy/Caddyfile with sudo to look like this:

mydomain.com

reverse_proxy 127.0.0.1:8080

5. Reload caddy with:

sudo systemctl reload caddy

Visit https://<your-domain-name> to access code-server. Congratulations!

In a future release we plan to integrate Let's Encrypt directly with code-server to avoid the dependency on caddy.

Self Signed Certificate

note: Self signed certificates do not work with iPad and will cause a blank page. You'll have to use Let's Encrypt instead. See the FAQ.

Recommended reading: https://security.stackexchange.com/a/8112.

We recommend this as a last resort as self signed certificates do not work with iPads and can cause other bizarre issues. Not to mention all the warnings when you access code-server. Only use this if:

1. You do not want to buy a domain.
2. You cannot expose the remote machine to the internet.
3. You do not want to use SSH forwarding.

ssh into your instance and edit your code-server config file to use a randomly generated self signed certificate:

# Replaces "cert: false" with "cert: true" in the code-server config.
sed -i.bak 's/cert: false/cert: true/' ~/.config/code-server/config.yaml
# Replaces "bind-addr: 127.0.0.1:8080" with "bind-addr: 0.0.0.0:443" in the code-server config.
sed -i.bak 's/bind-addr: 127.0.0.1:8080/bind-addr: 0.0.0.0:443/' ~/.config/code-server/config.yaml
# Allows code-server to listen on port 443.
sudo setcap cap_net_bind_service=+ep /usr/lib/code-server/lib/node

Assuming you have been following the guide, restart code-server with:

systemctl --user restart code-server

Edit your instance and checkmark the allow HTTPS traffic option.

Visit https://<your-instance-ip> to access code-server. You'll get a warning when accessing but if you click through you should be good.

To avoid the warnings, you can use mkcert to create a self signed certificate trusted by your OS and then pass it into code-server via the cert and cert-key config fields.

Change the password?

Edit the code-server config file at ~/.config/code-server/config.yaml and then restart code-server with:

systemctl --user restart code-server

How do I securely access development web services?

If you're working on a web service and want to access it locally, code-server can proxy it for you.

See FAQ.md.