WAF: enforce body size limitation

[blotus]

Allow to enforce body size limitation in the appsec datasource itself:

• Action can be drop (drops the request) / partial (only process up to X bytes from the body) / allow (do not process the body at all)

This configuration is different from the one in coraza. Because we read the body ourselves before passing it to coraza, we need to be able to properly limit the amount of body buffered in memory.

For now, this only allows setting a global value used for all requests as handling this properly in pre_eval would require a lot of refactoring/changes.

[github-actions]

@blotus: There are no 'kind' label on this PR. You need a 'kind' label to generate the release automatically.

• /kind feature
• /kind enhancement
• /kind refactoring
• /kind fix
• /kind chore
• /kind dependencies

Details

I am a bot created to help the crowdsecurity developers manage community feedback and contributions. You can check out my manifest file to understand my behavior and what I can do. If you want to use this for your project, you can check out the BirthdayResearch/oss-governance-bot repository.

[github-actions]

@blotus: There are no area labels on this PR. You can add as many areas as you see fit.

• /area agent
• /area local-api
• /area cscli
• /area appsec
• /area security
• /area configuration

Details

I am a bot created to help the crowdsecurity developers manage community feedback and contributions. You can check out my manifest file to understand my behavior and what I can do. If you want to use this for your project, you can check out the BirthdayResearch/oss-governance-bot repository.

[codecov]

Codecov Report

❌ Patch coverage is 56.00000% with 33 lines in your changes missing coverage. Please review.
✅ Project coverage is 63.02%. Comparing base (b509db4) to head (1447741).
⚠️ Report is 5 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/appsec/appsec.go	17.64%	14 Missing ⚠️
pkg/appsec/waf_helpers.go	0.00%	11 Missing ⚠️
pkg/acquisition/modules/appsec/appsec_runner.go	53.84%	3 Missing and 3 partials ⚠️
pkg/appsec/request.go	93.93%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4355      +/-   ##
==========================================
+ Coverage   63.00%   63.02%   +0.02%     
==========================================
  Files         473      473              
  Lines       33497    33540      +43     
==========================================
+ Hits        21105    21139      +34     
- Misses      10279    10288       +9     
  Partials     2113     2113              

Flag	Coverage Δ
bats	46.53% <25.33%> (-0.04%)	⬇️
unit-linux	36.20% <54.66%> (+0.25%)	⬆️
unit-windows	24.67% <50.66%> (+0.24%)	⬆️

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[blotus]

/kind enhancement
/area appsec