Correlations: Add CreateCorrelation HTTP API (#51630)

* Correlations: add migration

* Correlations: Add CreateCorrelation API

* Correlations: Make correlations work with provisioning

* Handle version changes

* Fix lining error

* lint fixes

* rebuild betterer results

* add a UID to each correlation

* Fix lint errors

* add docs

* better wording in API docs

* remove leftover comment

* handle ds updates

* Fix error message typo

* add bad data test

* make correlations a separate table

* skip readonly check when provisioning correlations

* delete stale correlations when datasources are deleted

* restore provisioned readonly ds

* publish deletion event with full data

* generate swagger and HTTP API docs

* apply source datasource permission to create correlation API

* Fix tests & lint errors

* ignore empty deletion events

* fix last lint errors

* fix more lint error

* Only publish deletion event if datasource was actually deleted

* delete DS provisioning deletes correlations, added & fixed tests

* Fix unmarshalling tests

* Fix linting errors

* Fix deltion event tests

* fix small linting error

* fix lint errors

* update betterer

* fix test

* make path singular

* Revert "make path singular"

This reverts commit 420c3d315e.

* add integration tests

* remove unneeded id from correlations table

* update spec

* update leftover references to CorrelationDTO

* fix tests

* cleanup tests

* fix lint error

pkg/services/correlations/api.go

@@ -0,0 +1,49 @@
+package correlations
+
+import (
+	"errors"
+	"net/http"
+
+	"github.com/grafana/grafana/pkg/api/response"
+	"github.com/grafana/grafana/pkg/api/routing"
+	"github.com/grafana/grafana/pkg/middleware"
+	"github.com/grafana/grafana/pkg/models"
+	ac "github.com/grafana/grafana/pkg/services/accesscontrol"
+	"github.com/grafana/grafana/pkg/services/datasources"
+
+	"github.com/grafana/grafana/pkg/web"
+)
+
+func (s *CorrelationsService) registerAPIEndpoints() {
+	uidScope := datasources.ScopeProvider.GetResourceScopeUID(ac.Parameter(":uid"))
+	authorize := ac.Middleware(s.AccessControl)
+
+	s.RouteRegister.Group("/api/datasources/uid/:uid/correlations", func(entities routing.RouteRegister) {
+		entities.Post("/", middleware.ReqSignedIn, authorize(ac.ReqOrgAdmin, ac.EvalPermission(datasources.ActionWrite, uidScope)), routing.Wrap(s.createHandler))
+	})
+}
+
+// createHandler handles POST /datasources/uid/:uid/correlations
+func (s *CorrelationsService) createHandler(c *models.ReqContext) response.Response {
+	cmd := CreateCorrelationCommand{}
+	if err := web.Bind(c.Req, &cmd); err != nil {
+		return response.Error(http.StatusBadRequest, "bad request data", err)
+	}
+	cmd.SourceUID = web.Params(c.Req)[":uid"]
+	cmd.OrgId = c.OrgId
+
+	correlation, err := s.CreateCorrelation(c.Req.Context(), cmd)
+	if err != nil {
+		if errors.Is(err, ErrSourceDataSourceDoesNotExists) || errors.Is(err, ErrTargetDataSourceDoesNotExists) {
+			return response.Error(http.StatusNotFound, "Data source not found", err)
+		}
+
+		if errors.Is(err, ErrSourceDataSourceReadOnly) {
+			return response.Error(http.StatusForbidden, "Data source is read only", err)
+		}
+
+		return response.Error(http.StatusInternalServerError, "Failed to add correlation", err)
+	}
+
+	return response.JSON(http.StatusOK, CreateCorrelationResponse{Result: correlation, Message: "Correlation created"})
+}

pkg/services/correlations/correlations.go

@@ -0,0 +1,74 @@
+package correlations
+
+import (
+	"context"
+
+	"github.com/grafana/grafana/pkg/api/routing"
+	"github.com/grafana/grafana/pkg/bus"
+	"github.com/grafana/grafana/pkg/events"
+
+	"github.com/grafana/grafana/pkg/infra/log"
+	"github.com/grafana/grafana/pkg/services/accesscontrol"
+	"github.com/grafana/grafana/pkg/services/datasources"
+	"github.com/grafana/grafana/pkg/services/sqlstore"
+)
+
+func ProvideService(sqlStore *sqlstore.SQLStore, routeRegister routing.RouteRegister, ds datasources.DataSourceService, ac accesscontrol.AccessControl, bus bus.Bus) *CorrelationsService {
+	s := &CorrelationsService{
+		SQLStore:          sqlStore,
+		RouteRegister:     routeRegister,
+		log:               log.New("correlations"),
+		DataSourceService: ds,
+		AccessControl:     ac,
+	}
+
+	s.registerAPIEndpoints()
+
+	bus.AddEventListener(s.handleDatasourceDeletion)
+
+	return s
+}
+
+type Service interface {
+	CreateCorrelation(ctx context.Context, cmd CreateCorrelationCommand) (Correlation, error)
+	DeleteCorrelationsBySourceUID(ctx context.Context, cmd DeleteCorrelationsBySourceUIDCommand) error
+	DeleteCorrelationsByTargetUID(ctx context.Context, cmd DeleteCorrelationsByTargetUIDCommand) error
+}
+
+type CorrelationsService struct {
+	SQLStore          *sqlstore.SQLStore
+	RouteRegister     routing.RouteRegister
+	log               log.Logger
+	DataSourceService datasources.DataSourceService
+	AccessControl     accesscontrol.AccessControl
+}
+
+func (s CorrelationsService) CreateCorrelation(ctx context.Context, cmd CreateCorrelationCommand) (Correlation, error) {
+	return s.createCorrelation(ctx, cmd)
+}
+
+func (s CorrelationsService) DeleteCorrelationsBySourceUID(ctx context.Context, cmd DeleteCorrelationsBySourceUIDCommand) error {
+	return s.deleteCorrelationsBySourceUID(ctx, cmd)
+}
+
+func (s CorrelationsService) DeleteCorrelationsByTargetUID(ctx context.Context, cmd DeleteCorrelationsByTargetUIDCommand) error {
+	return s.deleteCorrelationsByTargetUID(ctx, cmd)
+}
+
+func (s CorrelationsService) handleDatasourceDeletion(ctx context.Context, event *events.DataSourceDeleted) error {
+	return s.SQLStore.InTransaction(ctx, func(ctx context.Context) error {
+		if err := s.deleteCorrelationsBySourceUID(ctx, DeleteCorrelationsBySourceUIDCommand{
+			SourceUID: event.UID,
+		}); err != nil {
+			return err
+		}
+
+		if err := s.deleteCorrelationsByTargetUID(ctx, DeleteCorrelationsByTargetUIDCommand{
+			TargetUID: event.UID,
+		}); err != nil {
+			return err
+		}
+
+		return nil
+	})
+}

pkg/services/correlations/database.go

@@ -0,0 +1,70 @@
+package correlations
+
+import (
+	"context"
+
+	"github.com/grafana/grafana/pkg/services/datasources"
+	"github.com/grafana/grafana/pkg/services/sqlstore"
+	"github.com/grafana/grafana/pkg/util"
+)
+
+// createCorrelation adds a correlation
+func (s CorrelationsService) createCorrelation(ctx context.Context, cmd CreateCorrelationCommand) (Correlation, error) {
+	correlation := Correlation{
+		UID:         util.GenerateShortUID(),
+		SourceUID:   cmd.SourceUID,
+		TargetUID:   cmd.TargetUID,
+		Label:       cmd.Label,
+		Description: cmd.Description,
+	}
+
+	err := s.SQLStore.WithTransactionalDbSession(ctx, func(session *sqlstore.DBSession) error {
+		var err error
+
+		query := &datasources.GetDataSourceQuery{
+			OrgId: cmd.OrgId,
+			Uid:   cmd.SourceUID,
+		}
+		if err = s.DataSourceService.GetDataSource(ctx, query); err != nil {
+			return ErrSourceDataSourceDoesNotExists
+		}
+
+		if !cmd.SkipReadOnlyCheck && query.Result.ReadOnly {
+			return ErrSourceDataSourceReadOnly
+		}
+
+		if err = s.DataSourceService.GetDataSource(ctx, &datasources.GetDataSourceQuery{
+			OrgId: cmd.OrgId,
+			Uid:   cmd.TargetUID,
+		}); err != nil {
+			return ErrTargetDataSourceDoesNotExists
+		}
+
+		_, err = session.Insert(correlation)
+		if err != nil {
+			return err
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		return Correlation{}, err
+	}
+
+	return correlation, 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})
+		return err
+	})
+}
+
+func (s CorrelationsService) deleteCorrelationsByTargetUID(ctx context.Context, cmd DeleteCorrelationsByTargetUIDCommand) error {
+	return s.SQLStore.WithDbSession(ctx, func(session *sqlstore.DBSession) error {
+		_, err := session.Delete(&Correlation{TargetUID: cmd.TargetUID})
+		return err
+	})
+}

pkg/services/correlations/models.go

@@ -0,0 +1,66 @@
+package correlations
+
+import (
+	"errors"
+)
+
+var (
+	ErrSourceDataSourceReadOnly           = errors.New("source data source is read only")
+	ErrSourceDataSourceDoesNotExists      = errors.New("source data source does not exist")
+	ErrTargetDataSourceDoesNotExists      = errors.New("target data source does not exist")
+	ErrCorrelationFailedGenerateUniqueUid = errors.New("failed to generate unique correlation UID")
+	ErrCorrelationIdentifierNotSet        = errors.New("source identifier and org id are needed to be able to edit correlations")
+)
+
+// Correlation is the model for correlations definitions
+type Correlation struct {
+	// Unique identifier of the correlation
+	// example: 50xhMlg9k
+	UID string `json:"uid" xorm:"pk 'uid'"`
+	// UID of the data source the correlation originates from
+	// example:d0oxYRg4z
+	SourceUID string `json:"sourceUid" xorm:"pk 'source_uid'"`
+	// UID of the data source the correlation points to
+	// example:PE1C5CBDA0504A6A3
+	TargetUID string `json:"targetUid" xorm:"target_uid"`
+	// Label identifying the correlation
+	// example: My Label
+	Label string `json:"label" xorm:"label"`
+	// Description of the correlation
+	// example: Logs to Traces
+	Description string `json:"description" xorm:"description"`
+}
+
+// CreateCorrelationResponse is the response struct for CreateCorrelationCommand
+// swagger:model
+type CreateCorrelationResponse struct {
+	Result Correlation `json:"result"`
+	// example: Correlation created
+	Message string `json:"message"`
+}
+
+// CreateCorrelationCommand is the command for creating a correlation
+// swagger:model
+type CreateCorrelationCommand struct {
+	// UID of the data source for which correlation is created.
+	SourceUID         string `json:"-"`
+	OrgId             int64  `json:"-"`
+	SkipReadOnlyCheck bool   `json:"-"`
+	// Target data source UID to which the correlation is created
+	// example:PE1C5CBDA0504A6A3
+	TargetUID string `json:"targetUid" binding:"Required"`
+	// Optional label identifying the correlation
+	// example: My label
+	Label string `json:"label"`
+	// Optional description of the correlation
+	// example: Logs to Traces
+	Description string `json:"description"`
+}
+
+type DeleteCorrelationsBySourceUIDCommand struct {
+	SourceUID string
+}
+
+type DeleteCorrelationsByTargetUIDCommand struct {
+	TargetUID string
+}