Sourcegraph HTTP and HTTPS/SSL configuration

Overview:

Single Docker image (sourcegraph/server): NGINX
Sourcegraph Cluster (Kubernetes): NGINX
Docker Compose: Caddy 2
Other Sourcegraph clusters (e.g. pure-docker)

Sourcegraph single Docker image and Sourcegraph Cluster (Kubernetes): NGINX

Sourcegraph's single Docker image and Kubernetes deployments use NGINX as a reverse proxy for the Sourcegraph front-end server, meaning NGINX proxies external HTTP (and HTTPS) requests to the Sourcegraph front-end.

NGINX and Sourcegraph architecture

Note: Non-sighted users can view a text-representation of this diagram.

Sourcegraph single instance (Docker)

The first time Sourcegraph is run, it will create an nginx.conf file at:

~/.sourcegraph/config/nginx.conf on the Docker/Sourcegraph host (presuming you're using the quickstart docker run command)
/etc/sourcegraph/nginx.conf inside the container

SSL support requires manual editing of the NGINX configuration file if using the quickstart docker run command as it presumes local or internal usage.

Sourcegraph Cluster (Kubernetes)

We use the ingress-nginx for Sourcegraph Cluster running on Kubernetes. Refer to the deploy-sourcegraph Configuration documentation for more information.

NGINX SSL/HTTPS configuration

If you have a valid SSL certificate

1. Copy your SSL certificate and key to ~/.sourcegraph/config (where the nginx.conf file is).

2. Edit nginx.conf so that port 7080 redirects to 7443 and 7443 is served with SSL. It should look like this:

...
http {
    ...
    server {
        listen 7080;
        return 301 https://$host:7443$request_uri;
    }

    server {
        # Do not remove. The contents of sourcegraph_server.conf can change
        # between versions and may include improvements to the configuration.
        include nginx/sourcegraph_server.conf;

        listen 7443 ssl;
        server_name sourcegraph.example.com;  # change to your URL
        ssl_certificate         sourcegraph.crt;
        ssl_certificate_key     sourcegraph.key;

        location / {
            ...
        }
    }
}

If you need an SSL certificate

There are a few options:

1. Generate a browser-trusted certificate using Let's Encrypt (Certbot)

On the Certbot homepage, select "Nginx" and the operating system of the machine hosting Sourcegraph.
Follow the instructions to install and run Certbot.
If there is currently a process (e.g., Sourcegraph) listening on port 80, you'll need to stop it before running Certbot:
```
docker stop $(docker ps | grep sourcegraph/server | awk '{ print $1 }')
```
When you get to the step describing how to run Certbot, use the "certonly" command: sudo certbot certonly --nginx.
When Certbot runs successfully, it will emit the key file privkey.pem and cert file fullchain.pem. These should be renamed to sourcegraph.key and sourcegraph.crt, respectively, if you are using the nginx.conf template mentioned in this doc.
Kill the NGINX server that Certbot started: killall nginx. Restart Sourcegraph:
```
docker start $(docker ps -a | grep sourcegraph/server | awk '{ print $1 }')
```
Now visit your Sourcegraph instance at https://${YOUR_URL}. If there are issues, debug by examining the Docker logs:
```
docker logs $(docker ps | grep sourcegraph/server | awk '{ print $1 }')
```

2. Generate a self-signed certificate

For instances that don't yet have a certificate from a globally trusted Certificate Authority (CA) provider.

3. Use your CDN's HTTPS proxy feature

Some CDNs such as Cloudflare can handle the HTTPS connection from the user's browser while allowing the underlying service to continue serving HTTP (or HTTPS with a self-signed certificate). View your CDN's documentation for more details.

Redirect to external HTTPS URL

The URL that clients should use to access Sourcegraph is defined in the externalURL property in site configuration. To enforce that clients access Sourcegraph via this URL (and not some other URL, such as an IP address or other non-https URL), add the following to nginx.conf (replacing https://sourcegraph.example.com with your external URL):

# Redirect non-HTTPS traffic to HTTPS.
server {
    listen 80;
    server_name _;

    location / {
        return 301 https://sourcegraph.example.com$request_uri;
    }
}

HTTP Strict Transport Security

HTTP Strict Transport Security instructs web clients to only communicate with the server over HTTPS. To configure it, add the following to nginx.conf (in the server block):

add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;

See add_header documentation and "Configuring HSTS in nginx" for more details.

Additional NGINX SSL configuration

See the NGINX SSL Termination guide and Configuring HTTPS Servers.

Next steps

You should configure Sourcegraph's externalURL in the site configuration (and restart the frontend instances) so that Sourcegraph knows its URL.

Sourcegraph via Docker Compose: Caddy 2

Sourcegraph's Docker Compose deployment uses Caddy 2 as its reverse proxy. The Docker Compose deployment ships with a few builtin templates that cover common scenarios for exposing Sourcegraph:

plain HTTP
HTTPS with automatically provisioned Let's Encrypt certificates
HTTPS with custom certificates that you provide

Usage instructions are provided via the caddy service's inline comments inside the docker-compose.yaml definition.

Other Sourcegraph clusters (e.g. pure-Docker)

NGINX is not included in the (pure-Docker deployment as it's designed to be minimal and not tied to any specific reverse proxy.

If NGINX is your preferred reverse proxy, we suggest using the official NGINX docker images and following their instructions for securing HTTP traffic with a proxied server.