Goflow fix failed to parse ip

[jsirianni]

Description of Changes

A user has the following error:

{
  "level": "error",
  "ts": "2021-06-23T15:13:23.145-0500",
  "msg": "Failed to parse netflow message%!(EXTRA zapcore.Field={error 26 0  error converting DstAddr to string: cannot convert byte slice to ip address, expected length of 4 or 16 got 0})",
  "operator_id": "$.dec6c632-c843-467f-a262-75fddb2f7a8e.goflow_input",
  "operator_type": "goflow_input"
}

When an ip address field is length zero, we get this error when instead we should be ignoring the field. I was able to replicate this error by adding the test cases in this PR. The issue is resolved by skipping ip address parsing if the value is empty.

• Log correct key that is failing to convert to an IP
• If ip address field is empty, skip parsing it instead of returning an error
• Add test cases for empty ip address fields
• Add test case for invalid ip address length (malformed address)

Please check that the PR fulfills these requirements

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)
• Add a changelog entry (for non-trivial bug fixes / features)
• CI passes

[djaglowski]

Log Files	Logs / Second	CPU Avg (%)	CPU Avg Δ (%)	Memory Avg (MB)	Memory Avg Δ (MB)
1	1000	1.4827853	+0.034441948	127.25377	-1.6217651
1	5000	5.034576	+0.32750034	139.26993	+5.1365814
1	10000	9.138108	-0.82742786	143.97481	-2.7619934
1	50000	46.2082	-2.0851402	176.06493	+3.6578674
1	100000	103.89996	+5.6227493	233.84294	-3.1095123
10	100	1.9482563	+0.17234683	131.39049	-2.4598694
10	500	5.896599	+0.41374874	139.6805	-0.43089294
10	1000	11.500098	-0.70541763	146.74165	-2.9137878
10	5000	50.481827	-5.9502563	177.28705	-0.18843079
10	10000	108.28174	-10.375099	228.3816	-5.027603

[codecov]

Codecov Report

Merging #336 (2f58c66) into master (f1682b4) will increase coverage by 0.19%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #336      +/-   ##
==========================================
+ Coverage   69.53%   69.73%   +0.19%     
==========================================
  Files         123      123              
  Lines        6489     6491       +2     
==========================================
+ Hits         4512     4526      +14     
+ Misses       1503     1488      -15     
- Partials      474      477       +3     

Impacted Files	Coverage Δ
operator/builtin/input/goflow/parse.go	90.48% <100.00%> (+10.48%)	⬆️
operator/builtin/output/newrelic/newrelic.go	71.03% <0.00%> (-0.93%)	⬇️
operator/builtin/output/forward/forward.go	56.52% <0.00%> (+1.45%)	⬆️
operator/builtin/output/otlp/otlp.go	65.43% <0.00%> (+3.70%)	⬆️
operator/builtin/input/tcp/tcp.go	73.68% <0.00%> (+4.39%)	⬆️

---

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[djaglowski]

Log Files	Logs / Second	CPU Avg (%)	CPU Avg Δ (%)	Memory Avg (MB)	Memory Avg Δ (MB)
1	1000	1.4310942	+0.12073064	127.726295	-0.7308731
1	5000	4.7069917	-0.43104744	137.61409	+0.029769897
1	10000	10.672364	+1.344574	145.40652	-1.2831268
1	50000	47.449066	+1.3091011	177.3684	+3.1423645
1	100000	89.052216	-0.9149475	227.33742	+0.35560608
10	100	1.8793962	+0.17245066	133.83728	+0.30818176
10	500	5.569044	-0.06899023	141.56883	-0.8162689
10	1000	11.534627	+0.77590847	146.86166	-1.0040436
10	5000	53.6561	+2.799549	176.32678	+1.8263855
10	10000	99.07312	+1.7139511	220.7003	+3.3544006