Make controller manager logs less chatty

[mflendrich]

Is there an existing issue for this?

• I have searched the existing issues

Problem Statement

There is a lot of output in the logs, including the initialization phase and normal operation.
Let's see if we can improve log readability for a user searching for a concrete problem.

time="2021-09-03T20:45:09Z" level=info msg="admission webhook server disabled"                                                                                                                                     
time="2021-09-03T20:45:09Z" level=info msg="diagnostics server disabled"                                                                                                                                           
time="2021-09-03T20:45:09Z" level=info msg="starting controller manager" commit=UNKNOWN logger=setup release=UNKNOWN repo=UNKNOWN                                                                                  
time="2021-09-03T20:45:09Z" level=info msg="the ingress class name has been set" logger=setup value=kong                                                                                                           
time="2021-09-03T20:45:09Z" level=info msg="building the manager runtime scheme and loading apis into the scheme" logger=setup                                                                                     
time="2021-09-03T20:45:09Z" level=info msg="getting the kubernetes client configuration" logger=setup                                                                                                              
W0903 20:45:09.013822       1 client_config.go:615] Neither --kubeconfig nor --master was specified.  Using the inClusterConfig.  This might not work.                                                             
time="2021-09-03T20:45:09Z" level=info msg="getting the kong admin api client configuration" logger=setup                                                                                                          
time="2021-09-03T20:45:09Z" level=info msg="tag filtering enabled" logger=setup tags="[\"managed-by-ingress-controller\"]"                                                                                         
time="2021-09-03T20:45:09Z" level=info msg="configuring and building the controller manager" logger=setup                                                                                                          
time="2021-09-03T20:45:09Z" level=info msg="metrics server is starting to listen" addr=":10255" logger=controller-runtime.metrics                                                                                  
time="2021-09-03T20:45:09Z" level=info msg="configuring and building the proxy cache server" logger=setup                                                                                                          
...

Proposed Solution

Reduce verbosity (logr does not support log levels) of logging by default, and ensure that normal operation results in only as much logging as necessary to see that KIC is up and running.

• make DP update log prints hidden by default

Additional information

No response

Acceptance Criteria

• Walked through the prints produced by a live instance of KIC
• DP update log prints hidden by default
• Any other reasonably unnecessary items hidden by default as well

[shaneutt]

#1893 is related to this (but there are no dependencies) as we will in time want to unify our controller manager logging implementation.