Fix access log field parsing

types/logs.go

@@ -88,6 +88,11 @@ func (f *FieldNames) Get() interface{} {
 // Set's argument is a string to be parsed to set the flag.
 // It's a space-separated list, so we split it.
 func (f *FieldNames) Set(value string) error {
+	// When arguments are passed through YAML, escaped double quotes
+	// might be added to this string, and they would break the last
+	// key/value pair. This ensures the string is clean.
+	value = strings.Trim(value, "\"")
+
 	fields := strings.Fields(value)
 
 	for _, field := range fields {
@@ -123,6 +128,11 @@ func (f *FieldHeaderNames) Get() interface{} {
 // Set's argument is a string to be parsed to set the flag.
 // It's a space-separated list, so we split it.
 func (f *FieldHeaderNames) Set(value string) error {
+	// When arguments are passed through YAML, escaped double quotes
+	// might be added to this string, and they would break the last
+	// key/value pair. This ensures the string is clean.
+	value = strings.Trim(value, "\"")
+
 	fields := strings.Fields(value)
 
 	for _, field := range fields {

types/logs_test.go

@@ -301,6 +301,14 @@ func TestFieldsHeadersNamesSet(t *testing.T) {
 				"X-HEADER-2": "bar",
 			},
 		},
+		{
+			desc:  "Two values separated by space with escaped double quotes should return FieldNames of size 2",
+			value: "\"X-HEADER-1=foo X-HEADER-2=bar\"",
+			expected: &FieldHeaderNames{
+				"X-HEADER-1": "foo",
+				"X-HEADER-2": "bar",
+			},
+		},
 	}
 
 	for _, test := range testCases {