feat: support for external middleware plugins #83

michaeladler · 2023-11-20T16:20:58Z

Description

This commit introduces possibility to integrate external middleware plugins. These plugins have the possibility to modify incoming HTTP requests prior to routing. This includes modifying headers, routing and denying requests.

Due to the lack of a proper plugin system in Go, external middleware plugins are implemented as standalone sub-processes. They communicate with wfx via protobuf message over stdin/stdout, hence it's crucial for the plugin to read from stdin promptly to avoid blocking wfx. An example plugin written in Go is included in the example/plugin subdirectory, taking special care that stdin does not block.

Issues Addressed

List and link all the issues addressed by this PR.

Change Type

Please select the relevant options:

Bug fix (non-breaking change that resolves an issue)
New feature (non-breaking change that adds functionality)
Breaking change (fix or feature that would cause existing functionality to not work as expected)
This change requires a documentation update

Checklist

I have read the CONTRIBUTING document.
My changes adhere to the established code style, patterns, and best practices.
I have added tests that demonstrate the effectiveness of my changes.
I have updated the documentation accordingly (if applicable).
I have added an entry in the CHANGELOG to document my changes (if applicable).

codecov · 2023-11-20T16:23:53Z

Codecov Report

Attention: 62 lines in your changes are missing coverage. Please review.

Comparison is base (e38ac68) 79.85% compared to head (14037c9) 80.27%.

Files	Patch %	Lines
middleware/plugin/fbplugin.go	72.34%	19 Missing and 7 partials ⚠️
middleware/plugin/middleware.go	86.77%	11 Missing and 5 partials ⚠️
cmd/wfx/cmd/root/plugins.go	88.13%	4 Missing and 3 partials ⚠️
middleware/plugin/process_unix.go	81.25%	4 Missing and 2 partials ⚠️
middleware/plugin/ioutil/io.go	93.02%	2 Missing and 1 partial ⚠️
cmd/wfx/cmd/root/cmd.go	77.77%	2 Missing ⚠️
cmd/wfx/cmd/root/northbound.go	95.00%	1 Missing ⚠️
cmd/wfx/cmd/root/southbound.go	94.73%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #83      +/-   ##
==========================================
+ Coverage   79.85%   80.27%   +0.41%     
==========================================
  Files          85       89       +4     
  Lines        3376     3747     +371     
==========================================
+ Hits         2696     3008     +312     
- Misses        492      533      +41     
- Partials      188      206      +18

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cmd/wfx/cmd/root/flags.go

cmd/wfx/cmd/root/plugins_test.go

example/plugin/main.go

docs/operations.md

example/plugin/main.go

docs/operations.md

fbs/client/response.fbs

middleware/plugin/middleware.go

docs/operations.md

middleware/plugin/plugin.go

docs/operations.md

cmd/wfx/cmd/root/plugins.go

cmd/wfx/cmd/root/southbound.go

example/plugin/main.go

middleware/plugin/disabled.go

middleware/plugin/fbplugin.go

middleware/plugin/middleware.go

This commit introduces possibility to integrate external middleware plugins. These plugins have the possibility to modify incoming HTTP requests prior to routing. This includes modifying headers, routing and denying requests. Due to the lack of a proper plugin system in Go, external middleware plugins are implemented as standalone sub-processes. They communicate with wfx via protobuf message over stdin/stdout, hence it's crucial for the plugin to read from stdin promptly to avoid blocking wfx. An example plugin written in Go is included in the `example/plugin` subdirectory, taking special care that stdin does not block. Signed-off-by: Michael Adler <[email protected]>

michaeladler requested a review from stormc as a code owner November 20, 2023 16:20

michaeladler force-pushed the 43-plugin-system-for-external-middlewares branch 4 times, most recently from 521b212 to 35a8e04 Compare November 21, 2023 12:29

michaeladler marked this pull request as draft November 21, 2023 13:42

michaeladler force-pushed the 43-plugin-system-for-external-middlewares branch 11 times, most recently from 381dc8a to 58fe750 Compare November 23, 2023 10:18

michaeladler marked this pull request as ready for review November 23, 2023 10:22

michaeladler force-pushed the 43-plugin-system-for-external-middlewares branch from 58fe750 to 990b111 Compare December 1, 2023 09:43

stormc reviewed Dec 13, 2023

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michaeladler force-pushed the 43-plugin-system-for-external-middlewares branch from 990b111 to 7836279 Compare December 13, 2023 15:49

stormc reviewed Dec 13, 2023

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cmd/wfx/cmd/root/plugins_test.go Show resolved Hide resolved

stormc reviewed Dec 13, 2023

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michaeladler force-pushed the 43-plugin-system-for-external-middlewares branch 4 times, most recently from b032a83 to b642140 Compare December 15, 2023 12:29