53 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			Go
		
	
	
	
			
		
		
	
	
			53 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			Go
		
	
	
	
package middleware
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import (
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	"fmt"
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	"net/http"
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	"github.com/justinas/alice"
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)
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func NewHealthCheck(paths, userAgents []string) alice.Constructor {
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	return func(next http.Handler) http.Handler {
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		return healthCheck(paths, userAgents, next)
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	}
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}
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func healthCheck(paths, userAgents []string, next http.Handler) http.Handler {
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	// Use a map as a set to check health check paths
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	pathSet := make(map[string]struct{})
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	for _, path := range paths {
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		if len(path) > 0 {
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			pathSet[path] = struct{}{}
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		}
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	}
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	// Use a map as a set to check health check paths
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	userAgentSet := make(map[string]struct{})
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	for _, userAgent := range userAgents {
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		if len(userAgent) > 0 {
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			userAgentSet[userAgent] = struct{}{}
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		}
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	}
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	return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
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		if isHealthCheckRequest(pathSet, userAgentSet, req) {
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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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		next.ServeHTTP(rw, req)
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	})
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}
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func isHealthCheckRequest(paths, userAgents map[string]struct{}, req *http.Request) bool {
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	if _, ok := paths[req.URL.EscapedPath()]; ok {
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		return true
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	}
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	if _, ok := userAgents[req.Header.Get("User-Agent")]; ok {
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		return true
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	}
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	return false
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}
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