docs(metrics-addr): Use port 9323, allocated for Docker in prometheus

[fhemberger]

According to https://github.com/prometheus/prometheus/wiki/Default-port-allocations, 9323 is the default port associated with Docker metrics. It should be used in the example as well to avoid assigning a random port which may interfere with other prometheus exporters on the same machine.

[GordonTheTurtle]

Please sign your commits following these rules:
https://github.com/moby/moby/blob/master/CONTRIBUTING.md#sign-your-work
The easiest way to do this is to amend the last commit:

$ git clone -b "patch-1" git@github.com:fhemberger/cli.git somewhere
$ cd somewhere
$ git commit --amend -s --no-edit
$ git push -f

Amending updates the existing PR. You DO NOT need to open a new one.

[codecov-io]

Codecov Report

Merging #1589 into master will not change coverage.
The diff coverage is n/a.

@@ Coverage Diff @@## master #1589 +/- ##
=======================================
Coverage 55.25% 55.25% =======================================
Files 289 289 Lines 19395 19395 =======================================
Hits 10716 10716 Misses 7983 7983 Partials 696 696

[codecov-io]

Codecov Report

Merging #1589 into master will not change coverage.
The diff coverage is n/a.

@@ Coverage Diff @@## master #1589 +/- ##
=======================================
Coverage 55.25% 55.25% =======================================
Files 289 289 Lines 19395 19395 =======================================
Hits 10716 10716 Misses 7983 7983 Partials 696 696

[silvin-lubecki]

LGTM, thank you @fhemberger !

[thaJeztah]

Thanks! Overall looks good, but I left some suggestions.

Could you address those comments (and amend your commit, so that all changes are in a single commit)?

Based on the branch name (patch-1) I suspect you opened this PR through GitHub's web-interface, and amending a commit requires you to make those changes from the command line, so it's a bit more work to make those changes 😅

Let me know if you want to make those changes yourself, or if you want me to carry those (happy to make them for you)

[fhemberger]

@thaJeztah Thanks for your feedback, updated the PR. PTAL.

[thaJeztah]

perfect, LGTM!

thank you so much!

[fhemberger]

You're welcome!