41 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			Go
		
	
	
	
			
		
		
	
	
			41 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			Go
		
	
	
	
| package middleware
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| 
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| import (
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| 	"context"
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| 	"fmt"
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| 	"net/http"
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| 
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| 	"github.com/justinas/alice"
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| )
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| 
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| // Verifiable an interface for an object that has a connection to external
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| // data source and exports a function to validate that connection
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| type Verifiable interface {
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| 	VerifyConnection(context.Context) error
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| }
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| 
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| // NewReadynessCheck returns a middleware that performs deep health checks
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| // (verifies the connection to any underlying store) on a specific `path`
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| func NewReadynessCheck(path string, verifiable Verifiable) alice.Constructor {
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| 	return func(next http.Handler) http.Handler {
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| 		return readynessCheck(path, verifiable, next)
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| 	}
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| }
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| 
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| func readynessCheck(path string, verifiable Verifiable, next http.Handler) http.Handler {
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| 	return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
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| 		if path != "" && req.URL.EscapedPath() == path {
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| 			if err := verifiable.VerifyConnection(req.Context()); err != nil {
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| 				rw.WriteHeader(http.StatusInternalServerError)
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| 				fmt.Fprintf(rw, "error: %v", err)
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| 				return
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| 			}
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| 			rw.WriteHeader(http.StatusOK)
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| 			fmt.Fprintf(rw, "OK")
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| 			return
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| 		}
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| 
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| 		next.ServeHTTP(rw, req)
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| 	})
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| }
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