Metrics endpoint | Admin port | username | make it configurable

[sammetb]

As I saw in the documentation and in discussion with the solution team from Mendix we could set a different password for the M2EE user. https://github.com/mendix/docker-mendix-buildpack#monitoring-the-runtime

As I used that the password for the MxAdmin user was changed and I would have to use still the MxAdmin user to login and scarpe the metrics data from the App.

Our company security enforces us to run each application in least privilege mode and don't allow to use a full administrator for metrics endpoints.

The M2EE_PASSWORD leads the user to the point that a different metrics user would be configured independent from the MxAdmin user, but that isn't the case here. If you look in the nginx.py file line 139 you will see this _generate_password_file({"MxAdmin": security.get_m2ee_password()}) The configurable m2ee_password would be set hardcoded for the MxAdmin. Here should be a m2ee_username also be possible to be set via constants. If nothing has been configured then it should fall back to the current configuration to the MxAdmin.

We are at the moment not able to use the admin endpoint because of the security policy in our company.

Could you please create a new constant for the m2ee user to be set. Thanks in advance.