Multiple Hostnames

Multiple Hostnames/Configurations for SSL Termination

The keeper/guacamole-ssl-nginx image is specifically intended to provide SSL termination for the Guacamole image provided by Keeper for KCM. Historically, this image supported only a single hostname and configuration:

    ssl:
        image: keeper/guacamole-ssl-nginx:2
        restart: unless-stopped
        ports:
            - "80:80"
            - "443:443"
        environment:
            SELF_SIGNED: "Y"
            ACCEPT_EULA: "Y"
            CONTENT_TYPE_OPTIONS: "Y"
            CONTENT_SECURITY_POLICY: "Y"
            GUACAMOLE_HOSTNAME: "guacamole"
            SSL_HOSTNAME: "example.net"

As of KCM 2.12.0, the keeper/guacamole-ssl-nginx image can be used with multiple hostnames and configurations via a special SERVERS environment variable that accepts YAML (or JSON).

The SERVERS variable must contain a YAML (or JSON) array of objects, where each object contains the name/value pairs of environment variables that should apply to that additional configuration. Any variable that is not specified is inherited from the top-level environment. For example:

    ssl:
        image: keeper/guacamole-ssl-nginx:2
        restart: unless-stopped
        ports:
            - "80:80"
            - "443:443"
        environment:
            SELF_SIGNED: "Y"
            ACCEPT_EULA: "Y"
            CONTENT_TYPE_OPTIONS: "Y"
            CONTENT_SECURITY_POLICY: "Y"
            GUACAMOLE_HOSTNAME: "guacamole"
            
            SERVERS: |
               - SSL_HOSTNAME: "example.net"
               - SSL_HOSTNAME: "*.example.net"

The above configuration would result in an NGINX instance that handles both example.net and *.example.net hostnames equivalently. Both will get their own self-signed certificates because SELF_SIGNED is set to Y.

A more complex example:

    ssl:
        image: keeper/guacamole-ssl-nginx:2
        restart: unless-stopped
        ports:
            - "80:80"
            - "443:443"
        environment:
            ACCEPT_EULA: "Y"
            CONTENT_TYPE_OPTIONS: "Y"
            CONTENT_SECURITY_POLICY: "Y"
            GUACAMOLE_HOSTNAME: "guacamole"
            
            SERVERS: |
               - SSL_HOSTNAME: "example.net"
                 LETSENCRYPT_ACCEPT_TOS: "Y"
                 [email protected]

               - SSL_HOSTNAME: "*.example.net"
                 SELF_SIGNED: "Y"

The above configuration would result in an NGINX instance that generates and uses a self-signed certificate for *.example.net, but obtains a certificate for example.net from Let’s Encrypt.

IMPORTANT: The value of SERVERS must be a string, hence the | symbol within the above examples. If this symbol is omitted, then the YAML that follows is parsed as an object, and validation of the docker-compose.yml will fail, as all Docker environment variables must be strings.

NOTE: NGINX will use the first server as the default for any request that does not match any configured hostname. If any server declared in SERVERS should have this behavior, it must be the first server listed.