reuse filewatcher

[zirain]

1. reuse filewatcher package
2. move code under util

[codecov]

Codecov Report

Attention: Patch coverage is 59.49367% with 32 lines in your changes missing coverage. Please review.

Project coverage is 66.01%. Comparing base (f8c7056) to head (4a515d7).

Files with missing lines	Patch %	Lines
internal/provider/file/file.go	0.00%	26 Missing ⚠️
internal/filewatcher/worker.go	85.71%	2 Missing and 1 partial ⚠️
internal/utils/path/path.go	86.95%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4475      +/-   ##
==========================================
+ Coverage   65.61%   66.01%   +0.40%     
==========================================
  Files         211      209       -2     
  Lines       31961    31774     -187     
==========================================
+ Hits        20970    20977       +7     
+ Misses       9752     9556     -196     
- Partials     1239     1241       +2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

---

🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests

[zirain]

cc @shawnh2 PTAL

[shawnh2]

Done some test, seems running envoy-gateway server -c config.yaml with config.yaml:

apiVersion: gateway.envoyproxy.io/v1alpha1
kind: EnvoyGateway
gateway:
  controllerName: gateway.envoyproxy.io/gatewayclass-controller
provider:
  type: Custom
  custom:
    resource:
      type: File
      file:
        paths: ["test/"]
logging:
  level:
    default: info

cannot catch any modifications (like vim, echo etc) under the paths.

[zirain]

@shawnh2 can you review and test this again?