InfluxDB: Fix tag interpolation when varable used within a regex pattern (#82785)

* fix tag interpolation

* remove redundant variables

pkg/tsdb/influxdb/models/query.go

@@ -14,9 +14,7 @@ import (
 var (
 	regexpOperatorPattern           = regexp.MustCompile(`^\/.*\/$`)
 	regexpMeasurementPattern        = regexp.MustCompile(`^\/.*\/$`)
-	regexMatcherSimple              = regexp.MustCompile(`^/(.*)/$`)
 	regexMatcherWithStartEndPattern = regexp.MustCompile(`^/\^(.*)\$/$`)
-	mustEscapeCharsMatcher          = regexp.MustCompile(`[\\^$*+?.()|[\]{}\/]`)
 )
 
 func (query *Query) Build(queryContext *backend.QueryDataRequest) (string, error) {
@@ -112,7 +110,7 @@ func (query *Query) renderTags() []string {
 		var textValue string
 		switch tag.Operator {
 		case "=~", "!~", "":
-			textValue = escape(tag.Value)
+			textValue = tag.Value
 		case "<", ">", ">=", "<=":
 			textValue = removeRegexWrappers(tag.Value, `'`)
 		case "Is", "Is Not":
@@ -258,44 +256,3 @@ func removeRegexWrappers(wrappedValue string, wrapper string) string {
 
 	return value
 }
-
-func escape(unescapedValue string) string {
-	pipe := `|`
-	beginning := `/^`
-	ending := `$/`
-	value := unescapedValue
-	substitute := `\$0`
-	fullMatch := false
-
-	// get the value only in between /^...$/
-	matches := regexMatcherWithStartEndPattern.FindStringSubmatch(unescapedValue)
-	if len(matches) > 1 {
-		// full match. the value is like /^value$/
-		value = matches[1]
-		fullMatch = true
-	}
-
-	if !fullMatch {
-		// get the value only in between /.../
-		matches = regexMatcherSimple.FindStringSubmatch(unescapedValue)
-		if len(matches) > 1 {
-			value = matches[1]
-			beginning = `/`
-			ending = `/`
-		}
-	}
-
-	// split them with pipe |
-	parts := strings.Split(value, pipe)
-	for i, v := range parts {
-		// escape each item
-		parts[i] = mustEscapeCharsMatcher.ReplaceAllString(v, substitute)
-	}
-
-	// stitch them to each other
-	escaped := make([]byte, 0, 64)
-	escaped = append(escaped, beginning...)
-	escaped = append(escaped, strings.Join(parts, pipe)...)
-	escaped = append(escaped, ending...)
-	return string(escaped)
-}

pkg/tsdb/influxdb/models/query_test.go

@@ -304,30 +304,6 @@ func TestInfluxdbQueryBuilder(t *testing.T) {
 			require.Equal(t, query.renderMeasurement(), ` FROM "policy"./apa/`)
 		})
 
-		t.Run("can render regexp tags", func(t *testing.T) {
-			query := &Query{Tags: []*Tag{{Operator: "=~", Value: `/etc/hosts|/etc/hostname`, Key: "key"}}}
-
-			require.Equal(t, `"key" =~ /^\/etc\/hosts|\/etc\/hostname$/`, strings.Join(query.renderTags(), ""))
-		})
-
-		t.Run("can render regexp tags 2", func(t *testing.T) {
-			query := &Query{Tags: []*Tag{{Operator: "=~", Value: `/^/etc/hosts$/`, Key: "key"}}}
-
-			require.Equal(t, `"key" =~ /^\/etc\/hosts$/`, strings.Join(query.renderTags(), ""))
-		})
-
-		t.Run("can render regexp tags 3", func(t *testing.T) {
-			query := &Query{Tags: []*Tag{{Operator: "=~", Value: `/etc/hosts`, Key: "key"}}}
-
-			require.Equal(t, `"key" =~ /^\/etc\/hosts$/`, strings.Join(query.renderTags(), ""))
-		})
-
-		t.Run("can render regexp tags with dots in values", func(t *testing.T) {
-			query := &Query{Tags: []*Tag{{Operator: "=~", Value: `/etc/resolv.conf`, Key: "key"}}}
-
-			require.Equal(t, `"key" =~ /^\/etc\/resolv\.conf$/`, strings.Join(query.renderTags(), ""))
-		})
-
 		t.Run("can render single quoted tag value when regexed value has been sent", func(t *testing.T) {
 			query := &Query{Tags: []*Tag{{Operator: ">", Value: `/^12.2$/`, Key: "key"}}}
 

public/app/plugins/datasource/influxdb/datasource.ts

@@ -257,7 +257,12 @@ export default class InfluxDatasource extends DataSourceWithBackend<InfluxQuery,
         return {
           ...tag,
           key: this.templateSrv.replace(tag.key, scopedVars),
-          value: this.templateSrv.replace(tag.value, scopedVars, 'pipe'),
+          value: this.templateSrv.replace(
+            tag.value ?? '',
+            scopedVars,
+            (value: string | string[] = [], variable: QueryVariableModel) =>
+              this.interpolateQueryExpr(value, variable, tag.value)
+          ),
         };
       });
     }
@@ -286,7 +291,6 @@ export default class InfluxDatasource extends DataSourceWithBackend<InfluxQuery,
     };
   }
 
-  // this should only be used for rawQueries.
   interpolateQueryExpr(value: string | string[] = [], variable: QueryVariableModel, query?: string) {
     // If there is no query just return the value directly
     if (!query) {
@@ -297,7 +301,11 @@ export default class InfluxDatasource extends DataSourceWithBackend<InfluxQuery,
     // we always want to deal with special chars.
     if (variable.multi) {
       if (typeof value === 'string') {
-        return escapeRegex(value);
+        // Check the value is a number. If not run to escape special characters
+        if (isNaN(parseFloat(value))) {
+          return escapeRegex(value);
+        }
+        return value;
       }
 
       // If the value is a string array first escape them then join them with pipe

public/app/plugins/datasource/influxdb/datasource_backend_mode.test.ts

@@ -293,6 +293,22 @@ describe('InfluxDataSource Backend Mode', () => {
       const qData = fetchMock.mock.calls[0][0].data.queries[0].query;
       expect(qData).toBe(qe);
     });
+
+    it('should interpolate variable inside a regex pattern', () => {
+      const query: InfluxQuery = {
+        refId: 'A',
+        tags: [
+          {
+            key: 'key',
+            operator: '=~',
+            value: '/^.*-$var1$/',
+          },
+        ],
+      };
+      const res = ds.applyVariables(query, {});
+      const expected = `/^.*-var1$/`;
+      expect(res.tags?.[0].value).toEqual(expected);
+    });
   });
 
   describe('metric find query', () => {