Configurable caching for negative results (NXDOMAIN) (#287)

[kwitsch]

Changes:

• added cache.cacheTimeNegative (time.Duration)
• if not configured the default cache time stays at 30 min
• if set to a value below zero caching of negative responses is disabled

closes #287

[codecov]

Codecov Report

Merging #330 (d52a784) into development (f823db1) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##           development     #330   +/-   ##
============================================
  Coverage        96.26%   96.27%           
============================================
  Files               29       29           
  Lines             2198     2200    +2     
============================================
+ Hits              2116     2118    +2     
  Misses              53       53           
  Partials            29       29           

Impacted Files	Coverage Δ
config/config.go	92.80% <ø> (ø)
resolver/caching_resolver.go	100.00% <100.00%> (ø)

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[0xERR0R]

I think it is something from your local tests?

[kwitsch]

Yes

[0xERR0R]

Looks good for me, please run "go mod tidy" and commit the changes, I think there is something wrong

[kwitsch]

Looks good for me, please run "go mod tidy" and commit the changes, I think there is something wrong

Sorry currently not at home.
I can commit it tomorrow.

[0xERR0R]

Thanks for your work, I had some spare time today and I think we can merge it now