Dynamic Configuration Refactoring

old/middlewares/accesslog/parser.go

@@ -0,0 +1,54 @@
+package accesslog
+
+import (
+	"bytes"
+	"regexp"
+)
+
+// ParseAccessLog parse line of access log and return a map with each fields
+func ParseAccessLog(data string) (map[string]string, error) {
+	var buffer bytes.Buffer
+	buffer.WriteString(`(\S+)`)                  // 1 - ClientHost
+	buffer.WriteString(`\s-\s`)                  // - - Spaces
+	buffer.WriteString(`(\S+)\s`)                // 2 - ClientUsername
+	buffer.WriteString(`\[([^]]+)\]\s`)          // 3 - StartUTC
+	buffer.WriteString(`"(\S*)\s?`)              // 4 - RequestMethod
+	buffer.WriteString(`((?:[^"]*(?:\\")?)*)\s`) // 5 - RequestPath
+	buffer.WriteString(`([^"]*)"\s`)             // 6 - RequestProtocol
+	buffer.WriteString(`(\S+)\s`)                // 7 - OriginStatus
+	buffer.WriteString(`(\S+)\s`)                // 8 - OriginContentSize
+	buffer.WriteString(`("?\S+"?)\s`)            // 9 - Referrer
+	buffer.WriteString(`("\S+")\s`)              // 10 - User-Agent
+	buffer.WriteString(`(\S+)\s`)                // 11 - RequestCount
+	buffer.WriteString(`("[^"]*"|-)\s`)          // 12 - FrontendName
+	buffer.WriteString(`("[^"]*"|-)\s`)          // 13 - BackendURL
+	buffer.WriteString(`(\S+)`)                  // 14 - Duration
+
+	regex, err := regexp.Compile(buffer.String())
+	if err != nil {
+		return nil, err
+	}
+
+	submatch := regex.FindStringSubmatch(data)
+	result := make(map[string]string)
+
+	// Need to be > 13 to match CLF format
+	if len(submatch) > 13 {
+		result[ClientHost] = submatch[1]
+		result[ClientUsername] = submatch[2]
+		result[StartUTC] = submatch[3]
+		result[RequestMethod] = submatch[4]
+		result[RequestPath] = submatch[5]
+		result[RequestProtocol] = submatch[6]
+		result[OriginStatus] = submatch[7]
+		result[OriginContentSize] = submatch[8]
+		result[RequestRefererHeader] = submatch[9]
+		result[RequestUserAgentHeader] = submatch[10]
+		result[RequestCount] = submatch[11]
+		result[FrontendName] = submatch[12]
+		result[BackendURL] = submatch[13]
+		result[Duration] = submatch[14]
+	}
+
+	return result, nil
+}