Prometheus metric is not registered

[krpn]

Prometheus metrics must be registered. Not registered metrics are not avaliable in metrics path.

There are two ways to resolve it:
*Add metric registration in constructor
*Make metric variable public and delegate registration to developer

[hexdigest]

@krpn thank you for raising the issue!

I like the first option better. Please check the new version of the prometheus template.

[krpn]

Now it works. Thank you, @hexdigest.