fail if the provided user name is not k8s compliant

[MatousJobanek]

we should fail if the provided name of the user is not compliant with k8s names and label values.

[xcoulon]

we should fail if the provided name of the user is not compliant with k8s names and label values.

it's much simpler and much better than sanitizing the username, indeed!

[mfrancisc]

Thanks for implementing this check 🙏

I have few minor questions/clarifications.

[mfrancisc]

Great job!

Thanks for answering my questions 🙏

[alexeykazakov]

Thanks for the fix!

[fbm3307]

Thanks for this, i liked this approach

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 68.02%. Comparing base (4f14714) to head (2513f76).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #94      +/-   ##
==========================================
+ Coverage   67.78%   68.02%   +0.23%     
==========================================
  Files          44       44              
  Lines        3216     3240      +24     
==========================================
+ Hits         2180     2204      +24     
  Misses        841      841              
  Partials      195      195              

Files with missing lines	Coverage Δ
pkg/cmd/generate/cluster.go	85.71% <100.00%> (+8.79%)	⬆️