Limit serving of insecure metrics by allowing configurable IP

[swatisehgal]

Currently we are serving insecure metrics on all IPv4 routable addresses on the local machine (0.0.0.0).

In this PR, we make the metric IP configurable so that in order to ensure that we listen for insecure metrics port only ona configurable IP.

[ffromani]

LGTM

minor comments

[ffromani]

the e2e failure is curl failing with error 35 which is SSL connection error:
https://serverfault.com/questions/606135/curl-35-ssl-connect-error

[ffromani]

curl being obsolete is unlikely the culprit. Let's add -v to all the curl commandlines (curl -v -L ...) to have more debugging infos

[swatisehgal]

curl being obsolete is unlikely the culprit. Let's add -v to all the curl commandlines (curl -v -L ...) to have more debugging infos

Ack, will do now.

[swatisehgal]

the e2e failure is curl failing with error 35 which is SSL connection error: https://serverfault.com/questions/606135/curl-35-ssl-connect-error

  [FAILED] failed exec command on pod. pod="default/resource-topology-exporter-ds-cnkcw"; cmd=["curl" "-v" "-L" "https://127.0.0.1:2112/metrics"]; err=failed to run command [curl -v -L https://127.0.0.1:2112/metrics]: command terminated with exit code 35; stderr=""
  Unexpected error:
      <*fmt.wrapError | 0xc0002882c0>: 
      failed to run command [curl -v -L https://127.0.0.1:2112/metrics]: command terminated with exit code 35
      {
          msg: "failed to run command [curl -v -L https://127.0.0.1:2112/metrics]: command terminated with exit code 35",
          err: <exec.CodeExitError>{
              Err: <*errors.errorString | 0xc0000694c0>{
                  s: "command terminated with exit code 35",
              },
              Code: 35,
          },
      }
  occurred

I tried a few things suggested in the link you recommended as well as a few others but didn't have much luck.
Will investigate this tomorrow with a fresh mind.

[ffromani]

weird that -v doesn't give us more output, but I think I found the culprit anyway

[ffromani]

almost there, let's fix a minor error issue which survived the last round of updates and we can merge (and begin the backport dance)

[ffromani]

thanks, LGTM!