WhitelistOnly Fix for multiple entries

[c-f]

Problem

WhitelistOnly is only used, if no more than two whitelists are available or all clients include all whitelists.

Look at the following config snippet. Two Groups are defined, each with their own set of "whitelist" entries.

blocking:
 whiteLists:
   net_one:
      - net_one_whitelist.txt
   net_two:
      - net_two_whitelist.txt
  clientGroupsBlock:
    one-client*:
       - net_one
    two-client*:
       - net_two

clientLookup:
 clients:
   one-client-1:  [127.0.0.1]
   two-client-2:  [127.0.0.2]

If multiple WhitelistOnly groups are defined, then every client, which do NOT include ALL whitelists, can resolve non-whitelist items.
The reflect.DeepEqual() list now contains the check if [net_one] == [net_one, net_two], which will always return false.

Expected Behavior: Both clients are restricted to the defined whitelistOnly domains.

Behavior: None of them have whitelist enabled.

Possible solution

• if groupsToCheck contains ONE whitelistOnly group, then the client can only lookup whitelisted domains (this is implemented in the PR)
• if groupsToCheck groups are ALL whitelistOnly group, then the client can only lookup whitelisted domains

I changed the data type from slice to dict for performance reason.

Best regards,
c-f

[codecov]

Codecov Report

Merging #199 (b6029c9) into development (3770dd9) will decrease coverage by 0.21%.
The diff coverage is 100.00%.

@@               Coverage Diff               @@
##           development     #199      +/-   ##
===============================================
- Coverage        93.78%   93.56%   -0.22%     
===============================================
  Files               27       27              
  Lines             1738     1741       +3     
===============================================
- Hits              1630     1629       -1     
- Misses              80       84       +4     
  Partials            28       28              

Impacted Files	Coverage Δ
resolver/blocking_resolver.go	100.00% <100.00%> (ø)
resolver/query_logging_resolver.go	90.90% <0.00%> (-4.05%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 3770dd9...b6029c9. Read the comment docs.

[0xERR0R]

fixes #202

[0xERR0R]

@c-f Thank you for your work. I tested your PR and it works like a charm 👍