refactor datasource caching

pkg/api/dataproxy.go

@@ -1,62 +1,22 @@
 package api
 
 import (
-	"fmt"
-	"github.com/pkg/errors"
-	"time"
-
 	"github.com/grafana/grafana/pkg/api/pluginproxy"
-	"github.com/grafana/grafana/pkg/bus"
 	"github.com/grafana/grafana/pkg/metrics"
 	m "github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/plugins"
 )
 
-const HeaderNameNoBackendCache = "X-Grafana-NoCache"
-
-func (hs *HTTPServer) getDatasourceFromCache(id int64, c *m.ReqContext) (*m.DataSource, error) {
-	userPermissionsQuery := m.GetDataSourcePermissionsForUserQuery{
-		User: c.SignedInUser,
-	}
-	if err := bus.Dispatch(&userPermissionsQuery); err != nil {
-		if err != bus.ErrHandlerNotFound {
-			return nil, err
-		}
-	} else {
-		permissionType, exists := userPermissionsQuery.Result[id]
-		if exists && permissionType != m.DsPermissionQuery {
-			return nil, errors.New("User not allowed to access datasource")
-		}
-	}
-
-	nocache := c.Req.Header.Get(HeaderNameNoBackendCache) == "true"
-	cacheKey := fmt.Sprintf("ds-%d", id)
-
-	if !nocache {
-		if cached, found := hs.cache.Get(cacheKey); found {
-			ds := cached.(*m.DataSource)
-			if ds.OrgId == c.OrgId {
-				return ds, nil
-			}
-		}
-	}
-
-	query := m.GetDataSourceByIdQuery{Id: id, OrgId: c.OrgId}
-	if err := bus.Dispatch(&query); err != nil {
-		return nil, err
-	}
-
-	hs.cache.Set(cacheKey, query.Result, time.Second*5)
-	return query.Result, nil
-}
-
 func (hs *HTTPServer) ProxyDataSourceRequest(c *m.ReqContext) {
 	c.TimeRequest(metrics.M_DataSource_ProxyReq_Timer)
 
 	dsId := c.ParamsInt64(":id")
-	ds, err := hs.getDatasourceFromCache(dsId, c)
-
+	ds, err := hs.DatasourceCache.GetDatasource(dsId, c.SignedInUser, c.SkipCache)
 	if err != nil {
+		if err == m.ErrDataSourceAccessDenied {
+			c.JsonApiErr(403, "Access denied to datasource", nil)
+			return
+		}
 		c.JsonApiErr(500, "Unable to load datasource meta data", err)
 		return
 	}

pkg/api/http_server.go

@@ -16,7 +16,6 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 
-	gocache "github.com/patrickmn/go-cache"
 	macaron "gopkg.in/macaron.v1"
 
 	"github.com/grafana/grafana/pkg/api/live"
@@ -28,6 +27,8 @@ import (
 	"github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/plugins"
 	"github.com/grafana/grafana/pkg/registry"
+	"github.com/grafana/grafana/pkg/services/cache"
+	"github.com/grafana/grafana/pkg/services/datasources"
 	"github.com/grafana/grafana/pkg/services/hooks"
 	"github.com/grafana/grafana/pkg/services/rendering"
 	"github.com/grafana/grafana/pkg/setting"
@@ -46,19 +47,19 @@ type HTTPServer struct {
 	macaron       *macaron.Macaron
 	context       context.Context
 	streamManager *live.StreamManager
-	cache         *gocache.Cache
 	httpSrv       *http.Server
 
-	RouteRegister routing.RouteRegister `inject:""`
-	Bus           bus.Bus               `inject:""`
-	RenderService rendering.Service     `inject:""`
-	Cfg           *setting.Cfg          `inject:""`
-	HooksService  *hooks.HooksService   `inject:""`
+	RouteRegister   routing.RouteRegister    `inject:""`
+	Bus             bus.Bus                  `inject:""`
+	RenderService   rendering.Service        `inject:""`
+	Cfg             *setting.Cfg             `inject:""`
+	HooksService    *hooks.HooksService      `inject:""`
+	CacheService    *cache.CacheService      `inject:""`
+	DatasourceCache datasources.CacheService `inject:""`
 }
 
 func (hs *HTTPServer) Init() error {
 	hs.log = log.New("http.server")
-	hs.cache = gocache.New(5*time.Minute, 10*time.Minute)
 
 	hs.streamManager = live.NewStreamManager()
 	hs.macaron = hs.newMacaron()
@@ -231,6 +232,7 @@ func (hs *HTTPServer) addMiddlewaresAndStaticRoutes() {
 		m.Use(middleware.ValidateHostHeader(setting.Domain))
 	}
 
+	m.Use(middleware.HandleNoCacheHeader())
 	m.Use(middleware.AddDefaultResponseHeaders())
 }
 

pkg/api/metrics.go

@@ -25,8 +25,11 @@ func (hs *HTTPServer) QueryMetrics(c *m.ReqContext, reqDto dtos.MetricRequest) R
 		return Error(400, "Query missing datasourceId", nil)
 	}
 
-	ds, err := hs.getDatasourceFromCache(datasourceId, c)
+	ds, err := hs.DatasourceCache.GetDatasource(datasourceId, c.SignedInUser, c.SkipCache)
 	if err != nil {
+		if err == m.ErrDataSourceAccessDenied {
+			return Error(403, "Access denied to datasource", nil)
+		}
 		return Error(500, "Unable to load datasource meta data", err)
 	}