Load Balancers

Standard Load Balancer

Each Rack contains a built-in HTTPS load balancer.

For an app named myapp with a convox.yml like this:

    services:
      web:
        port: 3000

Convox will automatically set up HTTPS load balancing to this Service when it is deployed.

    $ convox services
    SERVICE  DOMAIN                               PORTS
    web      web.myapp.0a1b2c3d4e5f.convox.cloud  443:3000

You can then access the web Service of this App using https://web.myapp.0a1b2c3d4e5f.convox.cloud

SSL Termination

Convox will automatically configure SSL for the external Services of your app using a certificate from Lets Encrypt.

Convox will redirect HTTP requests on port 80 to HTTPS on port 443 using an HTTP 301 redirect.

Custom Domains

See Custom Domains

End-to-End Encryption

In the example above, a connection to your App would be HTTPS between the user and the Rack’s load balancer and then HTTP between the load balancer and the App.

If you would like this connection to be encrypted all the way to your App you must configure your App to listen for HTTPS on its defined port and update your convox.yml:

    services:
      web:
        port: https:3000

It is permissible to use a self-signed certificate between the Rack load balancer and your App.

Custom Load Balancers

If your App needs to expose arbitrary TCP ports to the outside world, you can configure custom Balancers.

For a convox.yml like this:

    balancers:
      other:
        service: web
        ports:
          5000: 3000
          5001: 3001
    services:
      web:
        ports:
          - 3000
          - 3001

Note the use of the ports attribute on this Service. Ports defined using ports are not exposed using the default load balancer.

Convox will configure a dedicated load balancer for each entry in the balancers: section.

    $ convox balancers
    BALANCER  SERVICE  ENDPOINT
    other     web      1.2.3.4

You could then access this Service using the following endpoints:

tcp://1.2.3.4:5000
tcp://1.2.3.4:5001
tcp://1.2.3.4:5002

Note that Convox will not configure SSL termination for ports on a custom Balancer.

Hybrid Load Balancing

It is possible to combine both of these load balancing types on a single Service.

For a convox.yml like this:

    balancers:
      other:
        service: web
        ports:
          6000: 4000
          6001: 4001
    services:
      web:
        port: 4000
        ports:
          - 4001

You would see the following at the CLI:

    $ convox services
    SERVICE  DOMAIN                               PORTS
    web      web.myapp.0a1b2c3d4e5f.convox.cloud  443:4000

    $ convox balancers
    BALANCER  SERVICE  ENDPOINT
    other     web      1.2.3.4

And you could access the Service using the following endpoints:

https://web.myapp.0a1b2c3d4e5f.convox.cloud
http://1.2.3.4:6000
tcp://1.2.4.5:6001

Note that port 4000 on this Service is exposed through both the standard and custom load balancers. SSL termination is not provided on the custom Balancer.