pkg/web: remove dependency injection (grafana#49123)

* pkg/web: store http.Handler internally

* pkg/web: remove injection

Removes any injection code from pkg/web.

It already was no longer functional, as we already only injected into
`http.Handler`, meaning we only inject ctx.Req and ctx.Resp.

Any other types (*Context, *ReqContext) were already accessed using the
http.Request.Context.Value() method.

* *: remove type mappings

Removes any call to the previously removed TypeMapper, as those were
non-functional already.

* pkg/web: remove Context.Invoke

was no longer used outside of pkg/web and also no longer functional

Author: sh0rez

pkg/api/common_test.go

@@ -411,10 +411,7 @@ func setupHTTPServerWithCfgDb(t *testing.T, useFakeAccessControl, enableAccessCo
 	m.Use(func(c *web.Context) {
 		initCtx.Context = c
 		initCtx.Logger = log.New("api-test")
-		c.Map(initCtx)
-
 		c.Req = c.Req.WithContext(ctxkey.Set(c.Req.Context(), initCtx))
-		c.Map(c.Req)
 	})
 
 	m.Use(accesscontrol.LoadPermissionsMiddleware(hs.AccessControl))

pkg/infra/usagestats/service/api_test.go

@@ -103,9 +103,6 @@ func contextProvider(tc *testContext) web.Handler {
 			SkipCache:    true,
 			Logger:       log.New("test"),
 		}
-		c.Map(reqCtx)
-
 		c.Req = c.Req.WithContext(ctxkey.Set(c.Req.Context(), reqCtx))
-		c.Map(c.Req)
 	}
 }

pkg/middleware/request_metrics.go

@@ -56,7 +56,6 @@ func RequestMetrics(features featuremgmt.FeatureToggles) web.Handler {
 		now := time.Now()
 		httpRequestsInFlight.Inc()
 		defer httpRequestsInFlight.Dec()
-		c.Map(c.Req)
 		c.Next()
 
 		handler := "unknown"

pkg/middleware/request_tracing.go

@@ -55,8 +55,6 @@ func RequestTracing(tracer tracing.Tracer) web.Handler {
 		ctx, span := tracer.Start(req.Context(), fmt.Sprintf("HTTP %s %s", req.Method, req.URL.Path), trace.WithLinks(trace.LinkFromContext(wireContext)))
 
 		c.Req = req.WithContext(ctx)
-		c.Map(c.Req)
-
 		c.Next()
 
 		// Only call span.Finish when a route operation name have been set,

pkg/services/accesscontrol/middleware_test.go

@@ -90,9 +90,6 @@ func contextProvider() web.Handler {
 			IsSignedIn:   true,
 			SkipCache:    true,
 		}
-		c.Map(reqCtx)
-
 		c.Req = c.Req.WithContext(ctxkey.Set(c.Req.Context(), reqCtx))
-		c.Map(c.Req)
 	}
 }

pkg/services/accesscontrol/resourcepermissions/api_test.go

@@ -500,10 +500,7 @@ func contextProvider(tc *testContext) web.Handler {
 			SkipCache:    true,
 			Logger:       log.New("test"),
 		}
-		c.Map(reqCtx)
-
 		c.Req = c.Req.WithContext(ctxkey.Set(c.Req.Context(), reqCtx))
-		c.Map(c.Req)
 	}
 }
 

pkg/services/contexthandler/contexthandler.go

@@ -95,9 +95,8 @@ func (h *ContextHandler) Middleware(mContext *web.Context) {
 		Logger:         log.New("context"),
 	}
 
-	// Inject ReqContext into a request context and replace the request instance in the macaron context
+	// Inject ReqContext into http.Request.Context
 	mContext.Req = mContext.Req.WithContext(ctxkey.Set(mContext.Req.Context(), reqContext))
-	mContext.Map(mContext.Req)
 
 	traceID := tracing.TraceIDFromContext(mContext.Req.Context(), false)
 	if traceID != "" {
@@ -153,8 +152,6 @@ func (h *ContextHandler) Middleware(mContext *web.Context) {
 			{Num: reqContext.UserId}},
 	)
 
-	mContext.Map(reqContext)
-
 	// update last seen every 5min
 	if reqContext.ShouldUpdateLastSeenAt() {
 		reqContext.Logger.Debug("Updating last user_seen_at", "user_id", reqContext.UserId)

pkg/services/ngalert/metrics/ngalert.go

@@ -12,7 +12,6 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promauto"
 
 	"github.com/grafana/grafana/pkg/api/response"
-	"github.com/grafana/grafana/pkg/api/routing"
 	"github.com/grafana/grafana/pkg/models"
 	legacyMetrics "github.com/grafana/grafana/pkg/services/alerting/metrics"
 	apimodels "github.com/grafana/grafana/pkg/services/ngalert/api/tooling/definitions"
@@ -279,20 +278,14 @@ func (m *OrgRegistries) RemoveOrgRegistry(org int64) {
 func Instrument(
 	method,
 	path string,
-	action interface{},
+	action func(*models.ReqContext) response.Response,
 	metrics *API,
 ) web.Handler {
 	normalizedPath := MakeLabelValue(path)
 
 	return func(c *models.ReqContext) {
 		start := time.Now()
-		var res response.Response
-		val, err := c.Invoke(action)
-		if err == nil && val != nil && len(val) > 0 {
-			res = val[0].Interface().(response.Response)
-		} else {
-			res = routing.ServerError(err)
-		}
+		res := action(c)
 
 		// TODO: We could look up the datasource type via our datasource service
 		var backend string

pkg/services/serviceaccounts/api/api_test.go

@@ -238,10 +238,7 @@ func setupTestServer(t *testing.T, svc *tests.ServiceAccountMock,
 			SignedInUser: signedUser,
 			Logger:       log.New("serviceaccounts-test"),
 		}
-		c.Map(ctx)
-
 		c.Req = c.Req.WithContext(ctxkey.Set(c.Req.Context(), ctx))
-		c.Map(c.Req)
 	})
 	a.RouterRegister.Register(m.Router)
 	return m, a

pkg/web/context.go

@@ -20,27 +20,16 @@ import (
 	"net"
 	"net/http"
 	"net/url"
-	"reflect"
 	"strconv"
 	"strings"
 
 	"github.com/grafana/grafana/pkg/infra/log"
 )
 
-// ContextInvoker is an inject.FastInvoker wrapper of func(ctx *Context).
-type ContextInvoker func(ctx *Context)
-
-// Invoke implements inject.FastInvoker which simplifies calls of `func(ctx *Context)` function.
-func (invoke ContextInvoker) Invoke(params []interface{}) ([]reflect.Value, error) {
-	invoke(params[0].(*Context))
-	return nil, nil
-}
-
 // Context represents the runtime context of current request of Macaron instance.
 // It is the integration of most frequently used middlewares and helper methods.
 type Context struct {
-	Injector
-	handlers []Handler
+	handlers []http.Handler
 	index    int
 
 	*Router
@@ -50,12 +39,12 @@ type Context struct {
 	logger   log.Logger
 }
 
-func (ctx *Context) handler() Handler {
+func (ctx *Context) handler() http.Handler {
 	if ctx.index < len(ctx.handlers) {
 		return ctx.handlers[ctx.index]
 	}
 	if ctx.index == len(ctx.handlers) {
-		return func() {}
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {})
 	}
 	panic("invalid index for context handler")
 }
@@ -68,9 +57,8 @@ func (ctx *Context) Next() {
 
 func (ctx *Context) run() {
 	for ctx.index <= len(ctx.handlers) {
-		if _, err := ctx.Invoke(ctx.handler()); err != nil {
-			panic(err)
-		}
+		ctx.handler().ServeHTTP(ctx.Resp, ctx.Req)
+
 		ctx.index++
 		if ctx.Resp.Written() {
 			return