My Grails app runs over HTTPS and in Config.groovy I've set:

environments {
    development {
        grails.serverURL = "https://localhost:8443/foo"
    }
}

When I execute grails run-app to start the app in dev mode, the last message printed on the console is:

Server running. Browse to http://localhost:8082/foo

If I accidentally click on this URL to access the application, I get various errors due to the same-origin security policy (because https://localhost:8443 is a different host to http://localhost:8082).

Why is Grails prompting me to access my app via http://localhost:8082/foo when I've set grails.serverURL = "https://localhost:8443/foo"

Update

I changed the startup command to grails run-app -https and the last message printed on the console is now:

Server running. Browse to http://localhost:8082/foo or https://localhost:8443/foo

Why am I given the option of either HTTP or HTTPS, rather than just the latter? Also, I get this exception during startup:

http11.Http11Protocol Failed to initialize end point associated with ProtocolHandler ["http-bio-8443"]
java.net.BindException: Address already in use <null>:8443
    at org.apache.tomcat.util.net.JIoEndpoint.bind(JIoEndpoint.java:407)

I've checked if port 8443 is in use before I run this command (it isn't), but the server seems to startup despite this exception, so this is not a major concern.

Replace grails.serverURL with the code below.

Its possible to set the port with the following system properties:

grails.server.port = 8082

That should work for both http and https. To configure for just one:

grails.server.port.https = 8082