OPENAPI: the rewrite header key formatting is odd; let's just make su…

…re all our bases are covered

config/paths.go

@@ -12,9 +12,17 @@ import (
 )
 
 const (
-	RewriteIdHeader = "RewriteId"
+	PascalCaseRewriteIdHeader = "Rewriteid"
+	SnakeCaseRewriteIdHeader  = "rewrite_id"
+	KebabCaseRewriteIdHeader  = "Rewrite-Id"
 )
 
+var rewriteIdHeaders = []string{
+	PascalCaseRewriteIdHeader,
+	SnakeCaseRewriteIdHeader,
+	KebabCaseRewriteIdHeader,
+}
+
 type PathRewrite struct {
 	RewrittenPath     string
 	PathConfiguration *shared.WiretapPathConfig
@@ -94,13 +102,49 @@ func rewriteTaget(path string, pathConfig *shared.WiretapPathConfig, configurati
 	}
 }
 
+func getRewriteIdHeaderValues(req *http.Request) ([]string, bool) {
+
+	// Let's first try to get the header with expected key names
+	for _, possibleHeaderKey := range rewriteIdHeaders {
+
+		if rewriteIdHeaderValues, ok := req.Header[possibleHeaderKey]; ok {
+			return rewriteIdHeaderValues, true
+		}
+
+		if rewriteIdHeaderValues, ok := req.Header[strings.ToLower(possibleHeaderKey)]; ok {
+			return rewriteIdHeaderValues, true
+		}
+
+	}
+
+	// Let's now try to ignore case ; this may produce collisions if a user has two headers with similar keys,
+	// but different capitalization. This is okay, as this is a last ditch effort to find any possible match
+	var loweredHeaders = make(http.Header)
+
+	for headerKey, headerValues := range req.Header {
+		for _, headerValue := range headerValues {
+			loweredHeaders.Set(strings.ToLower(headerKey), headerValue)
+		}
+	}
+
+	for _, possibleHeaderKey := range rewriteIdHeaders {
+
+		if rewriteIdHeaderValues, ok := loweredHeaders[strings.ToLower(possibleHeaderKey)]; ok {
+			return rewriteIdHeaderValues, true
+		}
+
+	}
+
+	return nil, false
+}
+
 func FindPathWithRewriteId(paths []*shared.WiretapPathConfig, req *http.Request) *shared.WiretapPathConfig {
 
 	if req == nil {
 		return nil
 	}
 
-	if rewriteIdHeaderValues, ok := req.Header[RewriteIdHeader]; ok {
+	if rewriteIdHeaderValues, ok := getRewriteIdHeaderValues(req); ok {
 		for _, pathRewriteConfig := range paths {
 
 			// Iterate through header values - since it's a multi-value field