Cartridge.port is broken for DIY cartridges.

[bjansen]

The following code fails when run on a DIY cartridge:

"The port you should bind to"
shared Integer port => requireInteger(environmentVariableName(name == "vertx" then "PORT" else "HTTP_PORT"));

The actual environment variable is not ending with HTTP_PORT:

OPENSHIFT_DIY_PORT=8080

[bjansen]

I'm not sure why it's ending with HTTP_PORT when it's a Ceylon cartridge, the official doc seems to indicate it's always PORT: https://developers.openshift.com/en/managing-environment-variables.html#informational-variables

I guess we could invert the logic like this:

"The port you should bind to"
shared Integer port => requireInteger(environmentVariableName(name == "ceylon" then "HTTP_PORT" else "PORT"));

[FroMage]

I'm fine with inverting the check. We could also try both...