Explore: Add transformations to correlation data links (#61799)

* bring in source from database

* bring in transformations from database

* add regex transformations to scopevar

* Consolidate types, add better example, cleanup

* Add var only if match

* Change ScopedVar to not require text, do not leak transformation-made variables between links

* Add mappings and start implementing logfmt

* Add mappings and start implementing logfmt

* Remove mappings, turn off global regex

* Add example yaml and omit transformations if empty

* Fix the yaml

* Add logfmt transformation

* Cleanup transformations and yaml

* add transformation field to FE types and use it, safeStringify logfmt values

* Add tests, only safe stringify if non-string, fix bug with safe stringify where it would return empty string with false value

* Add test for transformation field

* Do not add null transformations object

* Break out transformation logic, add tests to backend code

* Fix lint errors I understand 😅

* Fix the backend lint error

* Remove unnecessary code and mark new Transformations object as internal

* Add support for named capture groups

* Remove type assertion

* Remove variable name from transformation

* Add test for overriding regexes

* Add back variable name field, but change to mapValue

* fix go api test

* Change transformation types to enum, add better provisioning checks for bad type name and format

* Check for expression with regex transformations

pkg/tests/api/correlations/correlations_create_test.go

@@ -237,6 +237,8 @@ func TestIntegrationCreateCorrelation(t *testing.T) {
 		label := "a label"
 		fieldName := "fieldName"
 		configType := correlations.ConfigTypeQuery
+		transformation := correlations.Transformation{Type: "logfmt"}
+		transformation2 := correlations.Transformation{Type: "regex", Expression: "testExpression", MapValue: "testVar"}
 		res := ctx.Post(PostParams{
 			url: fmt.Sprintf("/api/datasources/uid/%s/correlations", writableDs),
 			body: fmt.Sprintf(`{
@@ -246,7 +248,11 @@ func TestIntegrationCreateCorrelation(t *testing.T) {
 					"config": {
 						"type": "%s",
 						"field": "%s",
-						"target": { "expr": "foo" }
+						"target": { "expr": "foo" },
+						"transformations": [
+							{"type": "logfmt"},
+							{"type": "regex", "expression": "testExpression", "mapValue": "testVar"}
+						]
 					}
 				}`, writableDs, description, label, configType, fieldName),
 			user: adminUser,
@@ -268,6 +274,8 @@ func TestIntegrationCreateCorrelation(t *testing.T) {
 		require.Equal(t, configType, response.Result.Config.Type)
 		require.Equal(t, fieldName, response.Result.Config.Field)
 		require.Equal(t, map[string]interface{}{"expr": "foo"}, response.Result.Config.Target)
+		require.Equal(t, transformation, response.Result.Config.Transformations[0])
+		require.Equal(t, transformation2, response.Result.Config.Transformations[1])
 
 		require.NoError(t, res.Body.Close())
 	})

pkg/tests/api/correlations/correlations_read_test.go

@@ -79,6 +79,9 @@ func TestIntegrationReadCorrelation(t *testing.T) {
 			Type:   correlations.ConfigTypeQuery,
 			Field:  "foo",
 			Target: map[string]interface{}{},
+			Transformations: []correlations.Transformation{
+				{Type: "logfmt"},
+			},
 		},
 	})
 

pkg/tests/api/correlations/correlations_update_test.go

@@ -287,7 +287,8 @@ func TestIntegrationUpdateCorrelation(t *testing.T) {
 				"config": {
 					"field": "field",
 					"type": "query",
-					"target": { "expr": "bar" }
+					"target": { "expr": "bar" },
+					"transformations": [ {"type": "logfmt"} ]
 				}
 			}`,
 		})
@@ -305,6 +306,7 @@ func TestIntegrationUpdateCorrelation(t *testing.T) {
 		require.Equal(t, "1", response.Result.Description)
 		require.Equal(t, "field", response.Result.Config.Field)
 		require.Equal(t, map[string]interface{}{"expr": "bar"}, response.Result.Config.Target)
+		require.Equal(t, correlations.Transformation{Type: "logfmt"}, response.Result.Config.Transformations[0])
 		require.NoError(t, res.Body.Close())
 
 		// partially updating only label