[Filebeat] [httpjson] Add support for single string containing multiple relation-types in getRFC5988Link (#32811)

kcreddy · web-flow · commit 9cab7759dc95 · 2022-08-25T20:50:08.000+05:30
* case with single string but multiple rel

* misspell lint error

* Add ascii doc
diff --git a/CHANGELOG.next.asciidoc b/CHANGELOG.next.asciidoc
@@ -117,6 +117,7 @@ https://github.com/elastic/beats/compare/v8.2.0\...main[Check the HEAD diff]
 - add documentation for decode_xml_wineventlog processor field mappings.  {pull}32456[32456]
 - httpjson input: Add request tracing logger. {issue}32402[32402] {pull}32412[32412]
 - Add cloudflare R2 to provider list in AWS S3 input. {pull}32620[32620]
+- Add support for single string containing multiple relation-types in getRFC5988Link. {pull}32811[32811]
 
 *Auditbeat*
 
diff --git a/x-pack/filebeat/input/httpjson/value_tpl.go b/x-pack/filebeat/input/httpjson/value_tpl.go
@@ -214,8 +214,8 @@ func parseTimestampNano(ns int64) time.Time {
 
 var regexpLinkRel = regexp.MustCompile(`<(.*)>;.*\srel\="?([^;"]*)`)
 
-func getRFC5988Link(rel string, links []string) string {
-	for _, link := range links {
+func getMatchLink(rel string, linksSplit []string) string {
+	for _, link := range linksSplit {
 		if !regexpLinkRel.MatchString(link) {
 			continue
 		}
@@ -231,10 +231,17 @@ func getRFC5988Link(rel string, links []string) string {
 
 		return matches[1]
 	}
-
 	return ""
 }
 
+func getRFC5988Link(rel string, links []string) string {
+	if len(links) == 1 && strings.Count(links[0], "rel=") > 1 {
+		linksSplit := strings.Split(links[0], ",")
+		return getMatchLink(rel, linksSplit)
+	}
+	return getMatchLink(rel, links)
+}
+
 func toInt(v interface{}) int64 {
 	vv := reflect.ValueOf(v)
 	switch vv.Kind() {
diff --git a/x-pack/filebeat/input/httpjson/value_tpl_test.go b/x-pack/filebeat/input/httpjson/value_tpl_test.go
@@ -189,7 +189,24 @@ func TestValueTpl(t *testing.T) {
 			expectedVal: "2020-11-05 13:25:32 +0000 UTC",
 		},
 		{
-			name:  "func getRFC5988Link",
+			name:  "func getRFC5988Link single rel matches",
+			value: `[[ getRFC5988Link "next" .last_response.header.Link ]]`,
+			paramCtx: &transformContext{
+				firstEvent: &mapstr.M{},
+				lastEvent:  &mapstr.M{},
+				lastResponse: newTestResponse(
+					nil,
+					http.Header{"Link": []string{
+						`<https://example.com/api/v1/users?after=00ubfjQEMYBLRUWIEDKK>; title="Page 3"; rel="next"`,
+					}},
+					"",
+				),
+			},
+			paramTr:     transformable{},
+			expectedVal: "https://example.com/api/v1/users?after=00ubfjQEMYBLRUWIEDKK",
+		},
+		{
+			name:  "func getRFC5988Link multiple rel as separate strings matches",
 			value: `[[ getRFC5988Link "previous" .last_response.header.Link ]]`,
 			paramCtx: &transformContext{
 				firstEvent: &mapstr.M{},
@@ -206,6 +223,60 @@ func TestValueTpl(t *testing.T) {
 			paramTr:     transformable{},
 			expectedVal: "https://example.com/api/v1/users?before=00ubfjQEMYBLRUWIEDKK",
 		},
+		{
+			name:  "func getRFC5988Link multiple rel as separate strings in random order matches",
+			value: `[[ getRFC5988Link "previous" .last_response.header.Link ]]`,
+			paramCtx: &transformContext{
+				firstEvent: &mapstr.M{},
+				lastEvent:  &mapstr.M{},
+				lastResponse: newTestResponse(
+					nil,
+					http.Header{"Link": []string{
+						`<https://example.com/api/v1/users?before=00ubfjQEMYBLRUWIEDKK>; title="Page 1"; rel="previous"`,
+						`<https://example.com/api/v1/users?after=00ubfjQEMYBLRUWIEDKK>; title="Page 3"; rel="next"`,
+					}},
+					"",
+				),
+			},
+			paramTr:     transformable{},
+			expectedVal: "https://example.com/api/v1/users?before=00ubfjQEMYBLRUWIEDKK",
+		},
+		{
+			name:  "func getRFC5988Link multiple rel as single string matches",
+			value: `[[ getRFC5988Link "previous" .last_response.header.Link ]]`,
+			paramCtx: &transformContext{
+				firstEvent: &mapstr.M{},
+				lastEvent:  &mapstr.M{},
+				lastResponse: newTestResponse(
+					nil,
+					http.Header{"Link": []string{
+						`<https://example.com/api/v1/users?before=00ubfjQEMYBLRUWIEDKK>; title="Page 1"; rel="previous",
+						<https://example.com/api/v1/users?after=00ubfjQEMYBLRUWIEDKK>; title="Page 3"; rel="next"`,
+					}},
+					"",
+				),
+			},
+			paramTr:     transformable{},
+			expectedVal: "https://example.com/api/v1/users?before=00ubfjQEMYBLRUWIEDKK",
+		},
+		{
+			name:  "func getRFC5988Link multiple rel as single string in random order matches",
+			value: `[[ getRFC5988Link "next" .last_response.header.Link ]]`,
+			paramCtx: &transformContext{
+				firstEvent: &mapstr.M{},
+				lastEvent:  &mapstr.M{},
+				lastResponse: newTestResponse(
+					nil,
+					http.Header{"Link": []string{
+						`<https://example.com/api/v1/users?before=00ubfjQEMYBLRUWIEDKK>; title="Page 1"; rel="previous",
+						<https://example.com/api/v1/users?after=00ubfjQEMYBLRUWIEDKK>; title="Page 3"; rel="next"`,
+					}},
+					"",
+				),
+			},
+			paramTr:     transformable{},
+			expectedVal: "https://example.com/api/v1/users?after=00ubfjQEMYBLRUWIEDKK",
+		},
 		{
 			name:  "func getRFC5988Link does not match",
 			value: `[[ getRFC5988Link "previous" .last_response.header.Link ]]`,
