Consider removing default port support

[fabxc]

Currently target hosts can be provided without a port name. Based on the scheme the default port is selected.

Prometheus is not a browser and usage of default ports is an exception rather than the rule. Removing this feature will give developers and users one thing less to think about.

Thoughts?

[juliusv]

Not sure if this behavior should be specific to a browser - port 80 and 443 are standard well-known default ports for HTTP and HTTPS, regardless of client application (http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?&page=2). So it might even be less surprising to keep it.

[fabxc]

Of course it's not specific to browsers — but for Prometheus, scraping from the default ports is not the normal case and a regular SD usually provides a port.
I just feel weird about interpolating the identifier for a scrape target, which should usually be a very explicit thing.

But not feeling too strong about it in general.

[juliusv]

Yeah, I don't feel strongly about this - do whatever feels best :)

[fabxc]

Ultimate compromise: we infer the port when we receive the target group and thus only create targets from full <host>:<port>s. (And remove a potential dead lock with that.)

[juliusv]

Can be closed now, I guess?

[fabxc]

Yes

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.