Correlations: Add GetCorrelation(s) HTTP APIs (#52517)

* Correlations: Get Single correlations

* Correlations: Get all correlations for given source ds

* Correlations: Get all correlations

* add tests

* add DB indices

* fix lint errors

* remove skip from tests

* use DatasourceService in test

docs/sources/developers/http_api/correlations.md

@@ -150,3 +150,126 @@ Status codes:
 
 - **200** – OK
 - **401** – Unauthorized
+- **404** – Not found, either source data source or correlation were not found
+- **500** – Internal error
+
+## Get all correlations originating from a given data source
+
+`GET /api/datasources/uid/:sourceUID/correlations`
+
+Get all correlations originating from the data source identified by the given `sourceUID` in the path.
+
+**Example request:**
+
+```http
+GET /api/datasources/uid/uyBf2637k/correlations HTTP/1.1
+Accept: application/json
+Authorization: Bearer eyJrIjoiT0tTcG1pUlY2RnVKZTFVaDFsNFZXdE9ZWmNrMkZYbk
+```
+
+**Example response:**
+
+```http
+HTTP/1.1 200
+Content-Type: application/json
+[
+```
+
+Status codes:
+
+- **200** – OK
+- **401** – Unauthorized
+- **404** – Not found, either source data source is not found or no correlation exists originating from the given data source
+- **500** – Internal error
+
+## Get all correlations
+
+`GET /api/datasources/correlations`
+
+Get all correlations.
+
+**Example request:**
+
+```http
+GET /api/datasources/correlations HTTP/1.1
+Accept: application/json
+Authorization: Bearer eyJrIjoiT0tTcG1pUlY2RnVKZTFVaDFsNFZXdE9ZWmNrMkZYbk
+```
+
+**Example response:**
+
+```http
+HTTP/1.1 200
+Content-Type: application/json
+[
+```
+
+Status codes:
+
+- **200** – OK
+- **401** – Unauthorized
+- **404** – Not found, no correlation is found
+- **500** – Internal error
+    "targetUID": "PDDA8E780A17E7EF1",
+    "uid": "J6gn7d31L"
+  },
+  {
+    "description": "Logs to Metrics",
+    "label": "Another Label",
+    "sourceUID": "uyBf2637k",
+    "targetUID": "P15396BDD62B2BE29",
+    "uid": "uWCpURgVk"
+  }
+]
+```
+
+Status codes:
+
+- **200** – OK
+- **401** – Unauthorized
+- **404** – Not found, either source data source is not found or no correlation exists originating from the given data source
+- **500** – Internal error
+
+## Get all correlations
+
+`GET /api/datasources/correlations`
+
+Get all correlations.
+
+**Example request:**
+
+```http
+GET /api/datasources/correlations HTTP/1.1
+Accept: application/json
+Authorization: Bearer eyJrIjoiT0tTcG1pUlY2RnVKZTFVaDFsNFZXdE9ZWmNrMkZYbk
+```
+
+**Example response:**
+
+```http
+HTTP/1.1 200
+Content-Type: application/json
+[
+  {
+    "description": "Prometheus to Loki",
+    "label": "My Label",
+    "sourceUID": "uyBf2637k",
+    "targetUID": "PDDA8E780A17E7EF1",
+    "uid": "J6gn7d31L"
+  },
+  {
+    "description": "Loki to Tempo",
+    "label": "Another Label",
+    "sourceUID": "PDDA8E780A17E7EF1",
+    "targetUID": "P15396BDD62B2BE29",
+    "uid": "uWCpURgVk"
+  }
+]
+```
+
+Status codes:
+
+- **200** – OK
+- **401** – Unauthorized
+- **404** – Not found, no correlation is found
+- **500** – Internal error

pkg/services/correlations/api.go

@@ -18,10 +18,17 @@ func (s *CorrelationsService) registerAPIEndpoints() {
 	uidScope := datasources.ScopeProvider.GetResourceScopeUID(ac.Parameter(":uid"))
 	authorize := ac.Middleware(s.AccessControl)
 
+	s.RouteRegister.Get("/api/datasources/correlations", middleware.ReqSignedIn, authorize(ac.ReqViewer, ac.EvalPermission(datasources.ActionRead)), routing.Wrap(s.getCorrelationsHandler))
+
 	s.RouteRegister.Group("/api/datasources/uid/:uid/correlations", func(entities routing.RouteRegister) {
+		entities.Get("/", middleware.ReqSignedIn, authorize(ac.ReqViewer, ac.EvalPermission(datasources.ActionRead)), routing.Wrap(s.getCorrelationsBySourceUIDHandler))
 		entities.Post("/", middleware.ReqSignedIn, authorize(ac.ReqOrgAdmin, ac.EvalPermission(datasources.ActionWrite, uidScope)), routing.Wrap(s.createHandler))
-		entities.Delete("/:correlationUID", middleware.ReqSignedIn, authorize(ac.ReqOrgAdmin, ac.EvalPermission(datasources.ActionWrite, uidScope)), routing.Wrap(s.deleteHandler))
-		entities.Patch("/:correlationUID", middleware.ReqSignedIn, authorize(ac.ReqOrgAdmin, ac.EvalPermission(datasources.ActionWrite, uidScope)), routing.Wrap(s.updateHandler))
+
+		entities.Group("/:correlationUID", func(entities routing.RouteRegister) {
+			entities.Get("/", middleware.ReqSignedIn, authorize(ac.ReqViewer, ac.EvalPermission(datasources.ActionRead)), routing.Wrap(s.getCorrelationHandler))
+			entities.Delete("/", middleware.ReqSignedIn, authorize(ac.ReqOrgAdmin, ac.EvalPermission(datasources.ActionWrite, uidScope)), routing.Wrap(s.deleteHandler))
+			entities.Patch("/", middleware.ReqSignedIn, authorize(ac.ReqOrgAdmin, ac.EvalPermission(datasources.ActionWrite, uidScope)), routing.Wrap(s.updateHandler))
+		})
 	})
 }
 
@@ -191,3 +198,125 @@ type UpdateCorrelationResponse struct {
 	// in: body
 	Body UpdateCorrelationResponseBody `json:"body"`
 }
+
+// swagger:route GET /datasources/uid/{sourceUID}/correlations/{correlationUID} correlations getCorrelation
+//
+// Gets a correlation.
+//
+// Responses:
+// 200: getCorrelationResponse
+// 401: unauthorisedError
+// 404: notFoundError
+// 500: internalServerError
+func (s *CorrelationsService) getCorrelationHandler(c *models.ReqContext) response.Response {
+	query := GetCorrelationQuery{
+		UID:       web.Params(c.Req)[":correlationUID"],
+		SourceUID: web.Params(c.Req)[":uid"],
+		OrgId:     c.OrgId,
+	}
+
+	correlation, err := s.getCorrelation(c.Req.Context(), query)
+	if err != nil {
+		if errors.Is(err, ErrCorrelationNotFound) {
+			return response.Error(http.StatusNotFound, "Correlation not found", err)
+		}
+		if errors.Is(err, ErrSourceDataSourceDoesNotExists) {
+			return response.Error(http.StatusNotFound, "Source data source not found", err)
+		}
+
+		return response.Error(http.StatusInternalServerError, "Failed to update correlation", err)
+	}
+
+	return response.JSON(http.StatusOK, correlation)
+}
+
+// swagger:parameters getCorrelation
+type GetCorrelationParams struct {
+	// in:path
+	// required:true
+	DatasourceUID string `json:"sourceUID"`
+	// in:path
+	// required:true
+	CorrelationUID string `json:"correlationUID"`
+}
+
+//swagger:response getCorrelationResponse
+type GetCorrelationResponse struct {
+	// in: body
+	Body Correlation `json:"body"`
+}
+
+// swagger:route GET /datasources/uid/{sourceUID}/correlations correlations getCorrelationsBySourceUID
+//
+// Gets all correlations originating from the given data source.
+//
+// Responses:
+// 200: getCorrelationsBySourceUIDResponse
+// 401: unauthorisedError
+// 404: notFoundError
+// 500: internalServerError
+func (s *CorrelationsService) getCorrelationsBySourceUIDHandler(c *models.ReqContext) response.Response {
+	query := GetCorrelationsBySourceUIDQuery{
+		SourceUID: web.Params(c.Req)[":uid"],
+		OrgId:     c.OrgId,
+	}
+
+	correlations, err := s.getCorrelationsBySourceUID(c.Req.Context(), query)
+	if err != nil {
+		if errors.Is(err, ErrCorrelationNotFound) {
+			return response.Error(http.StatusNotFound, "No correlation found", err)
+		}
+		if errors.Is(err, ErrSourceDataSourceDoesNotExists) {
+			return response.Error(http.StatusNotFound, "Source data source not found", err)
+		}
+
+		return response.Error(http.StatusInternalServerError, "Failed to update correlation", err)
+	}
+
+	return response.JSON(http.StatusOK, correlations)
+}
+
+// swagger:parameters getCorrelationsBySourceUID
+type GetCorrelationsBySourceUIDParams struct {
+	// in:path
+	// required:true
+	DatasourceUID string `json:"sourceUID"`
+}
+
+//swagger:response getCorrelationsBySourceUIDResponse
+type GetCorrelationsBySourceUIDResponse struct {
+	// in: body
+	Body []Correlation `json:"body"`
+}
+
+// swagger:route GET /datasources/correlations correlations getCorrelations
+//
+// Gets all correlations.
+//
+// Responses:
+// 200: getCorrelationsResponse
+// 401: unauthorisedError
+// 404: notFoundError
+// 500: internalServerError
+func (s *CorrelationsService) getCorrelationsHandler(c *models.ReqContext) response.Response {
+	query := GetCorrelationsQuery{
+		OrgId: c.OrgId,
+	}
+
+	correlations, err := s.getCorrelations(c.Req.Context(), query)
+	if err != nil {
+		if errors.Is(err, ErrCorrelationNotFound) {
+			return response.Error(http.StatusNotFound, "No correlation found", err)
+		}
+
+		return response.Error(http.StatusInternalServerError, "Failed to update correlation", err)
+	}
+
+	return response.JSON(http.StatusOK, correlations)
+}
+
+//swagger:response getCorrelationsResponse
+type GetCorrelationsResponse struct {
+	// in: body
+	Body []Correlation `json:"body"`
+}

pkg/services/correlations/correlations.go

@@ -56,6 +56,18 @@ func (s CorrelationsService) UpdateCorrelation(ctx context.Context, cmd UpdateCo
 	return s.updateCorrelation(ctx, cmd)
 }
 
+func (s CorrelationsService) GetCorrelation(ctx context.Context, cmd GetCorrelationQuery) (Correlation, error) {
+	return s.getCorrelation(ctx, cmd)
+}
+
+func (s CorrelationsService) GetCorrelationsBySourceUID(ctx context.Context, cmd GetCorrelationsBySourceUIDQuery) ([]Correlation, error) {
+	return s.getCorrelationsBySourceUID(ctx, cmd)
+}
+
+func (s CorrelationsService) GetCorrelations(ctx context.Context, cmd GetCorrelationsQuery) ([]Correlation, error) {
+	return s.getCorrelations(ctx, cmd)
+}
+
 func (s CorrelationsService) DeleteCorrelationsBySourceUID(ctx context.Context, cmd DeleteCorrelationsBySourceUIDCommand) error {
 	return s.deleteCorrelationsBySourceUID(ctx, cmd)
 }

pkg/services/correlations/database.go

@@ -132,6 +132,90 @@ func (s CorrelationsService) updateCorrelation(ctx context.Context, cmd UpdateCo
 	return correlation, nil
 }
 
+func (s CorrelationsService) getCorrelation(ctx context.Context, cmd GetCorrelationQuery) (Correlation, error) {
+	correlation := Correlation{
+		UID:       cmd.UID,
+		SourceUID: cmd.SourceUID,
+	}
+
+	err := s.SQLStore.WithTransactionalDbSession(ctx, func(session *sqlstore.DBSession) error {
+		query := &datasources.GetDataSourceQuery{
+			OrgId: cmd.OrgId,
+			Uid:   cmd.SourceUID,
+		}
+		if err := s.DataSourceService.GetDataSource(ctx, query); err != nil {
+			return ErrSourceDataSourceDoesNotExists
+		}
+
+		found, err := session.Where("uid = ? AND source_uid = ?", correlation.UID, correlation.SourceUID).Get(&correlation)
+		if !found {
+			return ErrCorrelationNotFound
+		}
+		if err != nil {
+			return err
+		}
+
+		return err
+	})
+
+	if err != nil {
+		return Correlation{}, err
+	}
+
+	return correlation, nil
+}
+
+func (s CorrelationsService) getCorrelationsBySourceUID(ctx context.Context, cmd GetCorrelationsBySourceUIDQuery) ([]Correlation, error) {
+	correlationsCondiBean := Correlation{
+		SourceUID: cmd.SourceUID,
+	}
+	correlations := make([]Correlation, 0)
+
+	err := s.SQLStore.WithTransactionalDbSession(ctx, func(session *sqlstore.DBSession) error {
+		query := &datasources.GetDataSourceQuery{
+			OrgId: cmd.OrgId,
+			Uid:   cmd.SourceUID,
+		}
+		if err := s.DataSourceService.GetDataSource(ctx, query); err != nil {
+			return ErrSourceDataSourceDoesNotExists
+		}
+
+		err := session.Find(&correlations, correlationsCondiBean)
+		if err != nil {
+			return err
+		}
+
+		return err
+	})
+
+	if err != nil {
+		return []Correlation{}, err
+	}
+
+	if len(correlations) == 0 {
+		return []Correlation{}, ErrCorrelationNotFound
+	}
+
+	return correlations, nil
+}
+
+func (s CorrelationsService) getCorrelations(ctx context.Context, cmd GetCorrelationsQuery) ([]Correlation, error) {
+	correlations := make([]Correlation, 0)
+
+	err := s.SQLStore.WithDbSession(ctx, func(session *sqlstore.DBSession) error {
+		return session.Select("correlation.*").Join("", "data_source", "correlation.source_uid = data_source.uid").Where("data_source.org_id = ?", cmd.OrgId).Find(&correlations)
+	})
+	if err != nil {
+		return []Correlation{}, err
+	}
+
+	if len(correlations) == 0 {
+		return []Correlation{}, ErrCorrelationNotFound
+	}
+
+	return correlations, nil
+}
+
 func (s CorrelationsService) deleteCorrelationsBySourceUID(ctx context.Context, cmd DeleteCorrelationsBySourceUIDCommand) error {
 	return s.SQLStore.WithDbSession(ctx, func(session *sqlstore.DBSession) error {
 		_, err := session.Delete(&Correlation{SourceUID: cmd.SourceUID})

pkg/services/correlations/models.go

@@ -94,6 +94,26 @@ type UpdateCorrelationCommand struct {
 	Description *string `json:"description"`
 }
 
+// GetCorrelationQuery is the query to retrieve a single correlation
+type GetCorrelationQuery struct {
+	// UID of the correlation
+	UID string `json:"-"`
+	// UID of the source data source
+	SourceUID string `json:"-"`
+	OrgId     int64  `json:"-"`
+}
+
+// GetCorrelationsBySourceUIDQuery is the query to retrieve all correlations originating by the given Data Source
+type GetCorrelationsBySourceUIDQuery struct {
+	SourceUID string `json:"-"`
+	OrgId     int64  `json:"-"`
+}
+
+// GetCorrelationsQuery is the query to retrieve all correlations
+type GetCorrelationsQuery struct {
+	OrgId int64 `json:"-"`
+}
+
 type DeleteCorrelationsBySourceUIDCommand struct {
 	SourceUID string
 }

pkg/services/sqlstore/migrations/correlations_mig.go

@@ -15,7 +15,14 @@ func addCorrelationsMigrations(mg *Migrator) {
 			{Name: "label", Type: DB_Text, Nullable: false},
 			{Name: "description", Type: DB_Text, Nullable: false},
 		},
+		Indices: []*Index{
+			{Cols: []string{"uid"}},
+			{Cols: []string{"source_uid"}},
+		},
 	}
 
 	mg.AddMigration("create correlation table v1", NewAddTableMigration(correlationsV1))
+
+	mg.AddMigration("add index correlations.uid", NewAddIndexMigration(correlationsV1, correlationsV1.Indices[0]))
+	mg.AddMigration("add index correlations.source_uid", NewAddIndexMigration(correlationsV1, correlationsV1.Indices[1]))
 }

pkg/tests/api/correlations/common_test.go

@@ -43,6 +43,20 @@ type User struct {
 	password string
 }
 
+type GetParams struct {
+	url  string
+	user User
+}
+
+func (c TestContext) Get(params GetParams) *http.Response {
+	c.t.Helper()
+
+	resp, err := http.Get(c.getURL(params.url, params.user))
+	require.NoError(c.t, err)
+
+	return resp
+}
+
 type PostParams struct {
 	url  string
 	body string
@@ -127,7 +141,7 @@ func (c TestContext) createUser(cmd user.CreateUserCommand) {
 func (c TestContext) createDs(cmd *datasources.AddDataSourceCommand) {
 	c.t.Helper()
 
-	err := c.env.SQLStore.AddDataSource(context.Background(), cmd)
+	err := c.env.Server.HTTPServer.DataSourcesService.AddDataSource(context.Background(), cmd)
 	require.NoError(c.t, err)
 }
 

pkg/tests/api/correlations/correlations_read_test.go

@@ -0,0 +1,315 @@
+package correlations
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"testing"
+
+	"github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/services/correlations"
+	"github.com/grafana/grafana/pkg/services/datasources"
+	"github.com/grafana/grafana/pkg/services/user"
+	"github.com/stretchr/testify/require"
+)
+
+func TestIntegrationReadCorrelation(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping integration test")
+	}
+	ctx := NewTestEnv(t)
+
+	adminUser := User{
+		username: "admin",
+		password: "admin",
+	}
+	viewerUser := User{
+		username: "viewer",
+		password: "viewer",
+	}
+
+	ctx.createUser(user.CreateUserCommand{
+		DefaultOrgRole: string(models.ROLE_VIEWER),
+		Password:       viewerUser.password,
+		Login:          viewerUser.username,
+	})
+	ctx.createUser(user.CreateUserCommand{
+		DefaultOrgRole: string(models.ROLE_ADMIN),
+		Password:       adminUser.password,
+		Login:          adminUser.username,
+	})
+
+	t.Run("Get all correlations", func(t *testing.T) {
+		// Running this here before creating a correlation in order to test this path.
+		t.Run("If no correlation exists it should return 404", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url:  "/api/datasources/correlations",
+				user: adminUser,
+			})
+			require.Equal(t, http.StatusNotFound, res.StatusCode)
+
+			responseBody, err := ioutil.ReadAll(res.Body)
+			require.NoError(t, err)
+
+			var response errorResponseBody
+			err = json.Unmarshal(responseBody, &response)
+			require.NoError(t, err)
+
+			require.Equal(t, "No correlation found", response.Message)
+
+			require.NoError(t, res.Body.Close())
+		})
+	})
+
+	createDsCommand := &datasources.AddDataSourceCommand{
+		Name:  "with-correlations",
+		Type:  "loki",
+		OrgId: 1,
+	}
+	ctx.createDs(createDsCommand)
+	dsWithCorrelations := createDsCommand.Result
+	correlation := ctx.createCorrelation(correlations.CreateCorrelationCommand{
+		SourceUID: dsWithCorrelations.Uid,
+		TargetUID: dsWithCorrelations.Uid,
+		OrgId:     dsWithCorrelations.OrgId,
+	})
+
+	createDsCommand = &datasources.AddDataSourceCommand{
+		Name:  "without-correlations",
+		Type:  "loki",
+		OrgId: 1,
+	}
+	ctx.createDs(createDsCommand)
+	dsWithoutCorrelations := createDsCommand.Result
+
+	t.Run("Get all correlations", func(t *testing.T) {
+		t.Run("Unauthenticated users shouldn't be able to read correlations", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url: "/api/datasources/correlations",
+			})
+			require.Equal(t, http.StatusUnauthorized, res.StatusCode)
+
+			responseBody, err := ioutil.ReadAll(res.Body)
+			require.NoError(t, err)
+
+			var response errorResponseBody
+			err = json.Unmarshal(responseBody, &response)
+			require.NoError(t, err)
+
+			require.Equal(t, "Unauthorized", response.Message)
+
+			require.NoError(t, res.Body.Close())
+		})
+
+		t.Run("Authenticated users shouldn't get unauthorized or forbidden errors", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url:  "/api/datasources/correlations",
+				user: viewerUser,
+			})
+			require.NotEqual(t, http.StatusUnauthorized, res.StatusCode)
+			require.NotEqual(t, http.StatusForbidden, res.StatusCode)
+
+			require.NoError(t, res.Body.Close())
+		})
+
+		t.Run("Should correctly return correlations", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url:  "/api/datasources/correlations",
+				user: adminUser,
+			})
+			require.Equal(t, http.StatusOK, res.StatusCode)
+
+			responseBody, err := ioutil.ReadAll(res.Body)
+			require.NoError(t, err)
+
+			var response []correlations.Correlation
+			err = json.Unmarshal(responseBody, &response)
+			require.NoError(t, err)
+
+			require.Len(t, response, 1)
+			require.EqualValues(t, correlation, response[0])
+
+			require.NoError(t, res.Body.Close())
+		})
+	})
+
+	t.Run("Get all correlations for a given data source", func(t *testing.T) {
+		t.Run("Unauthenticated users shouldn't be able to read correlations", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url: fmt.Sprintf("/api/datasources/uid/%s/correlations", "some-uid"),
+			})
+			require.Equal(t, http.StatusUnauthorized, res.StatusCode)
+
+			responseBody, err := ioutil.ReadAll(res.Body)
+			require.NoError(t, err)
+
+			var response errorResponseBody
+			err = json.Unmarshal(responseBody, &response)
+			require.NoError(t, err)
+
+			require.Equal(t, "Unauthorized", response.Message)
+
+			require.NoError(t, res.Body.Close())
+		})
+
+		t.Run("Authenticated users shouldn't get unauthorized or forbidden errors", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url:  fmt.Sprintf("/api/datasources/uid/%s/correlations", "some-uid"),
+				user: viewerUser,
+			})
+			require.NotEqual(t, http.StatusUnauthorized, res.StatusCode)
+			require.NotEqual(t, http.StatusForbidden, res.StatusCode)
+
+			require.NoError(t, res.Body.Close())
+		})
+
+		t.Run("if datasource does not exist it should return 404", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url:  fmt.Sprintf("/api/datasources/uid/%s/correlations", "some-uid"),
+				user: adminUser,
+			})
+			require.Equal(t, http.StatusNotFound, res.StatusCode)
+
+			responseBody, err := ioutil.ReadAll(res.Body)
+			require.NoError(t, err)
+
+			var response errorResponseBody
+			err = json.Unmarshal(responseBody, &response)
+			require.NoError(t, err)
+
+			require.Equal(t, "Source data source not found", response.Message)
+
+			require.NoError(t, res.Body.Close())
+		})
+
+		t.Run("If no correlation exists it should return 404", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url:  fmt.Sprintf("/api/datasources/uid/%s/correlations", dsWithoutCorrelations.Uid),
+				user: adminUser,
+			})
+			require.Equal(t, http.StatusNotFound, res.StatusCode)
+
+			responseBody, err := ioutil.ReadAll(res.Body)
+			require.NoError(t, err)
+
+			var response errorResponseBody
+			err = json.Unmarshal(responseBody, &response)
+			require.NoError(t, err)
+
+			require.Equal(t, "No correlation found", response.Message)
+
+			require.NoError(t, res.Body.Close())
+		})
+
+		t.Run("Should correctly return correlations", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url:  fmt.Sprintf("/api/datasources/uid/%s/correlations", dsWithCorrelations.Uid),
+				user: adminUser,
+			})
+			require.Equal(t, http.StatusOK, res.StatusCode)
+
+			responseBody, err := ioutil.ReadAll(res.Body)
+			require.NoError(t, err)
+
+			var response []correlations.Correlation
+			err = json.Unmarshal(responseBody, &response)
+			require.NoError(t, err)
+
+			require.Len(t, response, 1)
+			require.EqualValues(t, correlation, response[0])
+
+			require.NoError(t, res.Body.Close())
+		})
+	})
+
+	t.Run("Get a single correlation", func(t *testing.T) {
+		t.Run("Unauthenticated users shouldn't be able to read correlations", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url: fmt.Sprintf("/api/datasources/uid/%s/correlations/%s", "some-ds-uid", "some-correlation-uid"),
+			})
+			require.Equal(t, http.StatusUnauthorized, res.StatusCode)
+
+			responseBody, err := ioutil.ReadAll(res.Body)
+			require.NoError(t, err)
+
+			var response errorResponseBody
+			err = json.Unmarshal(responseBody, &response)
+			require.NoError(t, err)
+
+			require.Equal(t, "Unauthorized", response.Message)
+
+			require.NoError(t, res.Body.Close())
+		})
+
+		t.Run("Authenticated users shouldn't get unauthorized or forbidden errors", func(t *testing.T) {
+			// FIXME: don't skip this test
+			t.Skip("this test should pass but somehow testing with accesscontrol works different than live grafana")
+			res := ctx.Get(GetParams{
+				url:  fmt.Sprintf("/api/datasources/uid/%s/correlations/%s", "some-ds-uid", "some-correlation-uid"),
+				user: viewerUser,
+			})
+			require.NotEqual(t, http.StatusUnauthorized, res.StatusCode)
+			require.NotEqual(t, http.StatusForbidden, res.StatusCode)
+
+			require.NoError(t, res.Body.Close())
+		})
+
+		t.Run("if datasource does not exist it should return 404", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url:  fmt.Sprintf("/api/datasources/uid/%s/correlations/%s", "some-ds-uid", "some-correlation-uid"),
+				user: adminUser,
+			})
+			require.Equal(t, http.StatusNotFound, res.StatusCode)
+
+			responseBody, err := ioutil.ReadAll(res.Body)
+			require.NoError(t, err)
+
+			var response errorResponseBody
+			err = json.Unmarshal(responseBody, &response)
+			require.NoError(t, err)
+
+			require.Equal(t, "Source data source not found", response.Message)
+
+			require.NoError(t, res.Body.Close())
+		})
+
+		t.Run("If no correlation exists it should return 404", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url:  fmt.Sprintf("/api/datasources/uid/%s/correlations/%s", dsWithoutCorrelations.Uid, "some-correlation-uid"),
+				user: adminUser,
+			})
+			require.Equal(t, http.StatusNotFound, res.StatusCode)
+
+			responseBody, err := ioutil.ReadAll(res.Body)
+			require.NoError(t, err)
+
+			var response errorResponseBody
+			err = json.Unmarshal(responseBody, &response)
+			require.NoError(t, err)
+
+			require.Equal(t, "Correlation not found", response.Message)
+
+			require.NoError(t, res.Body.Close())
+		})
+
+		t.Run("Should correctly return correlation", func(t *testing.T) {
+			res := ctx.Get(GetParams{
+				url:  fmt.Sprintf("/api/datasources/uid/%s/correlations/%s", dsWithCorrelations.Uid, correlation.UID),
+				user: adminUser,
+			})
+			require.Equal(t, http.StatusOK, res.StatusCode)
+
+			responseBody, err := ioutil.ReadAll(res.Body)
+			require.NoError(t, err)
+
+			var response correlations.Correlation
+			err = json.Unmarshal(responseBody, &response)
+			require.NoError(t, err)
+
+			require.EqualValues(t, correlation, response)
+
+			require.NoError(t, res.Body.Close())
+		})
+	})
+}

public/api-merged.json

@@ -4020,6 +4020,27 @@
         }
       }
     },
+    "/datasources/correlations": {
+      "get": {
+        "tags": ["correlations"],
+        "summary": "Gets all correlations.",
+        "operationId": "getCorrelations",
+        "responses": {
+          "200": {
+            "$ref": "#/responses/getCorrelationsResponse"
+          },
+          "401": {
+            "$ref": "#/responses/unauthorisedError"
+          },
+          "404": {
+            "$ref": "#/responses/notFoundError"
+          },
+          "500": {
+            "$ref": "#/responses/internalServerError"
+          }
+        }
+      }
+    },
     "/datasources/id/{name}": {
       "get": {
         "description": "If you are running Grafana Enterprise and have Fine-grained access control enabled\nyou need to have a permission with action: `datasources:read` and scopes: `datasources:*`, `datasources:name:*` and `datasources:name:test_datasource` (single data source).",
@@ -4402,6 +4423,33 @@
       }
     },
     "/datasources/uid/{sourceUID}/correlations": {
+      "get": {
+        "tags": ["correlations"],
+        "summary": "Gets all correlations originating from the given data source.",
+        "operationId": "getCorrelationsBySourceUID",
+        "parameters": [
+          {
+            "type": "string",
+            "name": "sourceUID",
+            "in": "path",
+            "required": true
+          }
+        ],
+        "responses": {
+          "200": {
+            "$ref": "#/responses/getCorrelationsBySourceUIDResponse"
+          },
+          "401": {
+            "$ref": "#/responses/unauthorisedError"
+          },
+          "404": {
+            "$ref": "#/responses/notFoundError"
+          },
+          "500": {
+            "$ref": "#/responses/internalServerError"
+          }
+        }
+      },
       "post": {
         "tags": [
           "correlations"
@@ -4447,6 +4495,39 @@
       }
     },
     "/datasources/uid/{sourceUID}/correlations/{correlationUID}": {
+      "get": {
+        "tags": ["correlations"],
+        "summary": "Gets a correlation.",
+        "operationId": "getCorrelation",
+        "parameters": [
+          {
+            "type": "string",
+            "name": "sourceUID",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "name": "correlationUID",
+            "in": "path",
+            "required": true
+          }
+        ],
+        "responses": {
+          "200": {
+            "$ref": "#/responses/getCorrelationResponse"
+          },
+          "401": {
+            "$ref": "#/responses/unauthorisedError"
+          },
+          "404": {
+            "$ref": "#/responses/notFoundError"
+          },
+          "500": {
+            "$ref": "#/responses/internalServerError"
+          }
+        }
+      },
       "patch": {
         "tags": [
           "correlations"
@@ -19174,6 +19255,30 @@
         }
       }
     },
+    "getCorrelationResponse": {
+      "description": "(empty)",
+      "schema": {
+        "$ref": "#/definitions/Correlation"
+      }
+    },
+    "getCorrelationsBySourceUIDResponse": {
+      "description": "(empty)",
+      "schema": {
+        "type": "array",
+        "items": {
+          "$ref": "#/definitions/Correlation"
+        }
+      }
+    },
+    "getCorrelationsResponse": {
+      "description": "(empty)",
+      "schema": {
+        "type": "array",
+        "items": {
+          "$ref": "#/definitions/Correlation"
+        }
+      }
+    },
     "getCurrentOrgResponse": {
       "description": "(empty)",
       "schema": {

public/api-spec.json

@@ -3373,6 +3373,27 @@
         }
       }
     },
+    "/datasources/correlations": {
+      "get": {
+        "tags": ["correlations"],
+        "summary": "Gets all correlations.",
+        "operationId": "getCorrelations",
+        "responses": {
+          "200": {
+            "$ref": "#/responses/getCorrelationsResponse"
+          },
+          "401": {
+            "$ref": "#/responses/unauthorisedError"
+          },
+          "404": {
+            "$ref": "#/responses/notFoundError"
+          },
+          "500": {
+            "$ref": "#/responses/internalServerError"
+          }
+        }
+      }
+    },
     "/datasources/id/{name}": {
       "get": {
         "description": "If you are running Grafana Enterprise and have Fine-grained access control enabled\nyou need to have a permission with action: `datasources:read` and scopes: `datasources:*`, `datasources:name:*` and `datasources:name:test_datasource` (single data source).",
@@ -3755,6 +3776,33 @@
       }
     },
     "/datasources/uid/{sourceUID}/correlations": {
+      "get": {
+        "tags": ["correlations"],
+        "summary": "Gets all correlations originating from the given data source.",
+        "operationId": "getCorrelationsBySourceUID",
+        "parameters": [
+          {
+            "type": "string",
+            "name": "sourceUID",
+            "in": "path",
+            "required": true
+          }
+        ],
+        "responses": {
+          "200": {
+            "$ref": "#/responses/getCorrelationsBySourceUIDResponse"
+          },
+          "401": {
+            "$ref": "#/responses/unauthorisedError"
+          },
+          "404": {
+            "$ref": "#/responses/notFoundError"
+          },
+          "500": {
+            "$ref": "#/responses/internalServerError"
+          }
+        }
+      },
       "post": {
         "tags": [
           "correlations"
@@ -3800,6 +3848,39 @@
       }
     },
     "/datasources/uid/{sourceUID}/correlations/{correlationUID}": {
+      "get": {
+        "tags": ["correlations"],
+        "summary": "Gets a correlation.",
+        "operationId": "getCorrelation",
+        "parameters": [
+          {
+            "type": "string",
+            "name": "sourceUID",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "name": "correlationUID",
+            "in": "path",
+            "required": true
+          }
+        ],
+        "responses": {
+          "200": {
+            "$ref": "#/responses/getCorrelationResponse"
+          },
+          "401": {
+            "$ref": "#/responses/unauthorisedError"
+          },
+          "404": {
+            "$ref": "#/responses/notFoundError"
+          },
+          "500": {
+            "$ref": "#/responses/internalServerError"
+          }
+        }
+      },
       "patch": {
         "tags": [
           "correlations"
@@ -15173,6 +15254,30 @@
         }
       }
     },
+    "getCorrelationResponse": {
+      "description": "",
+      "schema": {
+        "$ref": "#/definitions/Correlation"
+      }
+    },
+    "getCorrelationsBySourceUIDResponse": {
+      "description": "",
+      "schema": {
+        "type": "array",
+        "items": {
+          "$ref": "#/definitions/Correlation"
+        }
+      }
+    },
+    "getCorrelationsResponse": {
+      "description": "",
+      "schema": {
+        "type": "array",
+        "items": {
+          "$ref": "#/definitions/Correlation"
+        }
+      }
+    },
     "getCurrentOrgResponse": {
       "description": "",
       "schema": {