ezadmis

README

ezadmis

Tools for building and registering Kubernetes admission webhooks

Usage

The library ezadmis can reduce the complexity of writing a kubernetes admission webhook .

All things you have to do is to implement a handler function.

type WebhookHandler func(ctx context.Context, req *admissionv1.AdmissionRequest, rw WebhookResponseWriter) (err error)

• Parameters
  • ctx, context of incoming request
  • request, incoming AdmissionRequest
  • patches, an optional output of JSONPatch operations for mutating webhook
• Return Values
  • deny, if not empty, indicating this AdmissionRequest should be denied, and a message will be returned
  • err, error occurred

Example

See ezadmis-httpcat/main.go

Tools

This repository provides two important tools

• ezadmis-install

  Reduce the complexity of installing an admission webhook

• ezadmis-httpcat

  Print the incoming AdmissionReview request for debugging

Extra Tools

See https://github.com/yankeguo/ezadmis-extra

Credits

GUO YANKE, MIT License

Documentation

Index

• func WrapWebhookHandler(opts WrapWebhookHandlerOptions, handler WebhookHandler) http.HandlerFunc
• type WebhookHandler
• type WebhookResponseWriter
• type WebhookServer
  • func NewWebhookServer(opts WebhookServerOptions) WebhookServer
• type WebhookServerOptions
  • func DefaultWebhookServerOptions() WebhookServerOptions
• type WrapWebhookHandlerOptions

Functions

func WrapWebhookHandler

func WrapWebhookHandler(opts WrapWebhookHandlerOptions, handler WebhookHandler) http.HandlerFunc

WrapWebhookHandler wrap WebhookHandler to http.HandlerFunc

Types

type WebhookHandler

type WebhookHandler func(ctx context.Context, req *admissionv1.AdmissionRequest, rw WebhookResponseWriter) (err error)

WebhookHandler function to modify incoming kubernetes resource;

type WebhookResponseWriter

type WebhookResponseWriter interface {
	// Deny deny this admission request
	Deny(deny string)
	// PatchRaw append a raw JSONPatch operation
	PatchRaw(patch map[string]any)
	// PatchAdd append a JSONPatch 'add' operation
	PatchAdd(path string, value any)
	// PatchRemove append a JSONPatch 'remove' operation
	PatchRemove(path string)
	// PatchReplace append a JSONPatch 'replace' operation
	PatchReplace(path string, value any)
	// PatchCopy append a JSONPatch 'copy' operation
	PatchCopy(path string, from string)
	// PatchMove append a JSONPatch 'move' operation
	PatchMove(path string, from string)
	// PatchTest append a JSONPatch 'test' operation
	PatchTest(path string, value any)

	// Build build a admission response
	Build(uid types.UID) (res *admissionv1.AdmissionResponse, err error)
}

WebhookResponseWriter response writer for WebhookHandler

type WebhookServer

type WebhookServer interface {
	// ListenAndServe wraps internal http.Server#ListenAndServeTLS()
	ListenAndServe() error

	// ListenAndServeGracefully ListenAndServe() with signal handling, perfect for using
	// inside main() as the only component
	ListenAndServeGracefully() error

	// Shutdown wraps internal http.Server#Shutdown()
	Shutdown(ctx context.Context) error
}

WebhookServer webhook server abstraction

func NewWebhookServer

func NewWebhookServer(opts WebhookServerOptions) WebhookServer

NewWebhookServer create a WebhookServer

type WebhookServerOptions

type WebhookServerOptions struct {
	Port     int
	CertFile string
	KeyFile  string
	Debug    bool
	Handler  WebhookHandler
}

WebhookServerOptions options for WebhookServer

func DefaultWebhookServerOptions

func DefaultWebhookServerOptions() WebhookServerOptions

DefaultWebhookServerOptions returns default options for WebhookServer

type WrapWebhookHandlerOptions

type WrapWebhookHandlerOptions struct {
	Debug bool
}

WrapWebhookHandlerOptions options for wrapping WebhookHandler