35 lines
738 B
Go
35 lines
738 B
Go
package requestid
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import (
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"context"
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"crypto/rand"
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"encoding/hex"
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"net/http"
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)
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type contextKey struct{}
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func Middleware(next http.Handler) http.Handler {
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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requestID := r.Header.Get("X-Request-Id")
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if requestID == "" {
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requestID = newID()
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}
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w.Header().Set("X-Request-Id", requestID)
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next.ServeHTTP(w, r.WithContext(context.WithValue(r.Context(), contextKey{}, requestID)))
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})
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}
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func FromContext(ctx context.Context) string {
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requestID, _ := ctx.Value(contextKey{}).(string)
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return requestID
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}
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func newID() string {
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var buf [16]byte
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if _, err := rand.Read(buf[:]); err != nil {
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return "req-fallback"
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}
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return hex.EncodeToString(buf[:])
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}
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