Extricates reusable utilities for different alerting proxy types (#32268)

* backendtype helper

* abstracts alertingproxy

* updates alerting api dep

* prom endpoints

go.mod

@@ -39,7 +39,7 @@ require (
 	github.com/google/go-cmp v0.5.5
 	github.com/google/uuid v1.2.0
 	github.com/gosimple/slug v1.9.0
-	github.com/grafana/alerting-api v0.0.0-20210323142651-d6515052e2f0
+	github.com/grafana/alerting-api v0.0.0-20210323194814-03a29a4c4c27
 	github.com/grafana/grafana-aws-sdk v0.2.0
 	github.com/grafana/grafana-plugin-model v0.0.0-20190930120109-1fc953a61fb4
 	github.com/grafana/grafana-plugin-sdk-go v0.89.0

go.sum

@@ -797,12 +797,8 @@ github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0U
 github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/gosimple/slug v1.9.0 h1:r5vDcYrFz9BmfIAMC829un9hq7hKM4cHUrsv36LbEqs=
 github.com/gosimple/slug v1.9.0/go.mod h1:AMZ+sOVe65uByN3kgEyf9WEBKBCSS+dJjMX9x4vDJbg=
-github.com/grafana/alerting-api v0.0.0-20210318231719-9499804fc548 h1:KjyaZJhPJ15Ul/+OQr8mbO7kDpU5i7G3r5FGVZKClTQ=
+github.com/grafana/alerting-api v0.0.0-20210323194814-03a29a4c4c27 h1:DuyuEAHJeI+CMxIyzCVhmHcIeK+sjqberhDUfrgd3PY=
-github.com/grafana/alerting-api v0.0.0-20210318231719-9499804fc548/go.mod h1:5IppnPguSHcCbVLGCVzVjBvuQZNbYgVJ4KyXXjhCyWY=
+github.com/grafana/alerting-api v0.0.0-20210323194814-03a29a4c4c27/go.mod h1:5IppnPguSHcCbVLGCVzVjBvuQZNbYgVJ4KyXXjhCyWY=
-github.com/grafana/alerting-api v0.0.0-20210323141138-8873de5bf07a h1:OGKDRdmQSXKFJelrJUf9O8Xh0C8u+OQG1NSurcBYpOI=
-github.com/grafana/alerting-api v0.0.0-20210323141138-8873de5bf07a/go.mod h1:5IppnPguSHcCbVLGCVzVjBvuQZNbYgVJ4KyXXjhCyWY=
-github.com/grafana/alerting-api v0.0.0-20210323142651-d6515052e2f0 h1:bMYGd71RigZvkLmcdedGdMDJXKJ20luqEQLbqjgAAjI=
-github.com/grafana/alerting-api v0.0.0-20210323142651-d6515052e2f0/go.mod h1:5IppnPguSHcCbVLGCVzVjBvuQZNbYgVJ4KyXXjhCyWY=
 github.com/grafana/grafana v1.9.2-0.20210308201921-4ce0a49eac03/go.mod h1:AHRRvd4utJGY25J5nW8aL7wZzn/LcJ0z2za9oOp14j4=
 github.com/grafana/grafana-aws-sdk v0.1.0/go.mod h1:+pPo5U+pX0zWimR7YBc7ASeSQfbRkcTyQYqMiAj7G5U=
 github.com/grafana/grafana-aws-sdk v0.2.0 h1:UTBBYwye+ad5YUIlwN7TGxLdz1wXN3Ezhl0pseDGRVA=

pkg/services/ngalert/api/api.go

@@ -45,11 +45,18 @@ type API struct {
 // RegisterAPIEndpoints registers API handlers
 func (api *API) RegisterAPIEndpoints() {
 	logger := log.New("ngalert.api")
+	proxy := &AlertingProxy{
+		DataProxy: api.DataProxy,
+	}
 	api.RegisterAlertmanagerApiEndpoints(AlertmanagerApiMock{log: logger})
-	api.RegisterPrometheusApiEndpoints(PrometheusApiMock{log: logger})
+	api.RegisterPrometheusApiEndpoints(NewForkedProm(
+		api.DatasourceCache,
+		NewLotexProm(proxy, logger),
+		PrometheusApiMock{log: logger},
+	))
 	api.RegisterRulerApiEndpoints(NewForkedRuler(
 		api.DatasourceCache,
-		&LotexRuler{DataProxy: api.DataProxy, log: logger},
+		NewLotexRuler(proxy, logger),
 		RulerApiMock{log: logger},
 	))
 	api.RegisterTestingApiEndpoints(TestingApiMock{log: logger})

pkg/services/ngalert/api/fork_ruler.go

@@ -2,7 +2,6 @@ package api
 
 import (
 	"fmt"
-	"strconv"
 
 	apimodels "github.com/grafana/alerting-api/pkg/api"
 	"github.com/grafana/grafana/pkg/api/response"
@@ -24,26 +23,8 @@ func NewForkedRuler(datasourceCache datasources.CacheService, lotex, grafana Rul
 	}
 }
 
-func (r *ForkedRuler) backendType(ctx *models.ReqContext) (apimodels.Backend, error) {
-	recipient := ctx.Params("Recipient")
-	if recipient == apimodels.GrafanaBackend.String() {
-		return apimodels.GrafanaBackend, nil
-	}
-	if datasourceID, err := strconv.ParseInt(recipient, 10, 64); err == nil {
-		if ds, err := r.DatasourceCache.GetDatasource(datasourceID, ctx.SignedInUser, ctx.SkipCache); err == nil {
-			switch ds.Type {
-			case "loki", "prometheus":
-				return apimodels.LoTexRulerBackend, nil
-			default:
-				return 0, fmt.Errorf("unexpected backend type (%v)", ds.Type)
-			}
-		}
-	}
-	return 0, fmt.Errorf("unexpected backend type (%v)", recipient)
-}
-
 func (r *ForkedRuler) RouteDeleteNamespaceRulesConfig(ctx *models.ReqContext) response.Response {
-	t, err := r.backendType(ctx)
+	t, err := backendType(ctx, r.DatasourceCache)
 	if err != nil {
 		return response.Error(400, err.Error(), nil)
 	}
@@ -58,7 +39,7 @@ func (r *ForkedRuler) RouteDeleteNamespaceRulesConfig(ctx *models.ReqContext) re
 }
 
 func (r *ForkedRuler) RouteDeleteRuleGroupConfig(ctx *models.ReqContext) response.Response {
-	t, err := r.backendType(ctx)
+	t, err := backendType(ctx, r.DatasourceCache)
 	if err != nil {
 		return response.Error(400, err.Error(), nil)
 	}
@@ -73,7 +54,7 @@ func (r *ForkedRuler) RouteDeleteRuleGroupConfig(ctx *models.ReqContext) respons
 }
 
 func (r *ForkedRuler) RouteGetNamespaceRulesConfig(ctx *models.ReqContext) response.Response {
-	t, err := r.backendType(ctx)
+	t, err := backendType(ctx, r.DatasourceCache)
 	if err != nil {
 		return response.Error(400, err.Error(), nil)
 	}
@@ -88,7 +69,7 @@ func (r *ForkedRuler) RouteGetNamespaceRulesConfig(ctx *models.ReqContext) respo
 }
 
 func (r *ForkedRuler) RouteGetRulegGroupConfig(ctx *models.ReqContext) response.Response {
-	t, err := r.backendType(ctx)
+	t, err := backendType(ctx, r.DatasourceCache)
 	if err != nil {
 		return response.Error(400, err.Error(), nil)
 	}
@@ -103,7 +84,7 @@ func (r *ForkedRuler) RouteGetRulegGroupConfig(ctx *models.ReqContext) response.
 }
 
 func (r *ForkedRuler) RouteGetRulesConfig(ctx *models.ReqContext) response.Response {
-	t, err := r.backendType(ctx)
+	t, err := backendType(ctx, r.DatasourceCache)
 	if err != nil {
 		return response.Error(400, err.Error(), nil)
 	}
@@ -118,7 +99,7 @@ func (r *ForkedRuler) RouteGetRulesConfig(ctx *models.ReqContext) response.Respo
 }
 
 func (r *ForkedRuler) RoutePostNameRulesConfig(ctx *models.ReqContext, conf apimodels.RuleGroupConfig) response.Response {
-	backendType, err := r.backendType(ctx)
+	backendType, err := backendType(ctx, r.DatasourceCache)
 	if err != nil {
 		return response.Error(400, err.Error(), nil)
 	}

pkg/services/ngalert/api/forked_prom.go

@@ -0,0 +1,55 @@
+package api
+
+import (
+	"fmt"
+
+	apimodels "github.com/grafana/alerting-api/pkg/api"
+	"github.com/grafana/grafana/pkg/api/response"
+	"github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/services/datasources"
+)
+
+type ForkedPromSvc struct {
+	ProxySvc, GrafanaSvc PrometheusApiService
+	DatasourceCache      datasources.CacheService
+}
+
+func NewForkedProm(datasourceCache datasources.CacheService, proxy, grafana PrometheusApiService) *ForkedPromSvc {
+	return &ForkedPromSvc{
+		ProxySvc:        proxy,
+		GrafanaSvc:      grafana,
+		DatasourceCache: datasourceCache,
+	}
+}
+
+func (p *ForkedPromSvc) RouteGetAlertStatuses(ctx *models.ReqContext) response.Response {
+	t, err := backendType(ctx, p.DatasourceCache)
+	if err != nil {
+		return response.Error(400, err.Error(), nil)
+	}
+
+	switch t {
+	case apimodels.GrafanaBackend:
+		return p.GrafanaSvc.RouteGetAlertStatuses(ctx)
+	case apimodels.LoTexRulerBackend:
+		return p.ProxySvc.RouteGetAlertStatuses(ctx)
+	default:
+		return response.Error(400, fmt.Sprintf("unexpected backend type (%v)", t), nil)
+	}
+}
+
+func (p *ForkedPromSvc) RouteGetRuleStatuses(ctx *models.ReqContext) response.Response {
+	t, err := backendType(ctx, p.DatasourceCache)
+	if err != nil {
+		return response.Error(400, err.Error(), nil)
+	}
+
+	switch t {
+	case apimodels.GrafanaBackend:
+		return p.GrafanaSvc.RouteGetRuleStatuses(ctx)
+	case apimodels.LoTexRulerBackend:
+		return p.ProxySvc.RouteGetRuleStatuses(ctx)
+	default:
+		return response.Error(400, fmt.Sprintf("unexpected backend type (%v)", t), nil)
+	}
+}

pkg/services/ngalert/api/lotex.go

@@ -2,7 +2,6 @@ package api
 
 import (
 	"bytes"
-	"encoding/json"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -10,96 +9,25 @@ import (
 	"net/url"
 
 	apimodels "github.com/grafana/alerting-api/pkg/api"
-	"gopkg.in/macaron.v1"
 	"gopkg.in/yaml.v3"
 
 	"github.com/grafana/grafana/pkg/api/response"
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/models"
-	"github.com/grafana/grafana/pkg/services/datasourceproxy"
 )
 
 const legacyRulerPrefix = "/api/prom/rules"
 
 type LotexRuler struct {
-	DataProxy *datasourceproxy.DatasourceProxyService
 	log log.Logger
+	*AlertingProxy
 }
 
-// macaron unsafely asserts the http.ResponseWriter is an http.CloseNotifier, which will panic.
+func NewLotexRuler(proxy *AlertingProxy, log log.Logger) *LotexRuler {
-// Here we impl it, which will ensure this no longer happens, but neither will we take
+	return &LotexRuler{
-// advantage cancelling upstream requests when the downstream has closed.
+		log:           log,
-// NB: http.CloseNotifier is a deprecated ifc from before the context pkg.
+		AlertingProxy: proxy,
-type safeMacaronWrapper struct {
-	http.ResponseWriter
-}
-
-func (w *safeMacaronWrapper) CloseNotify() <-chan bool {
-	return make(chan bool)
-}
-
-// replacedResponseWriter overwrites the underlying responsewriter used by a *models.ReqContext.
-// It's ugly because it needs to replace a value behind a few nested pointers.
-func replacedResponseWriter(ctx *models.ReqContext) (*models.ReqContext, *response.NormalResponse) {
-	resp := response.CreateNormalResponse(make(http.Header), nil, 0)
-	cpy := *ctx
-	cpyMCtx := *cpy.Context
-	cpyMCtx.Resp = macaron.NewResponseWriter(ctx.Req.Method, &safeMacaronWrapper{resp})
-	cpy.Context = &cpyMCtx
-	return &cpy, resp
-}
-
-// withReq proxies a different request
-func (r *LotexRuler) withReq(
-	ctx *models.ReqContext,
-	req *http.Request,
-	extractor func([]byte) (interface{}, error),
-) response.Response {
-	newCtx, resp := replacedResponseWriter(ctx)
-	newCtx.Req.Request = req
-	r.DataProxy.ProxyDatasourceRequestWithID(newCtx, ctx.ParamsInt64("Recipient"))
-
-	status := resp.Status()
-	if status >= 400 {
-		return response.Error(status, string(resp.Body()), nil)
 	}
-
-	t, err := extractor(resp.Body())
-	if err != nil {
-		return response.Error(500, err.Error(), nil)
-	}
-
-	b, err := json.Marshal(t)
-	if err != nil {
-		return response.Error(500, err.Error(), nil)
-	}
-
-	return response.JSON(status, b)
-}
-
-func yamlExtractor(v interface{}) func([]byte) (interface{}, error) {
-	return func(b []byte) (interface{}, error) {
-		decoder := yaml.NewDecoder(bytes.NewReader(b))
-		decoder.KnownFields(true)
-
-		err := decoder.Decode(v)
-
-		return v, err
-	}
-}
-
-func jsonExtractor(v interface{}) func([]byte) (interface{}, error) {
-	if v == nil {
-		// json unmarshal expects a pointer
-		v = &map[string]interface{}{}
-	}
-	return func(b []byte) (interface{}, error) {
-		return v, json.Unmarshal(b, v)
-	}
-}
-
-func messageExtractor(b []byte) (interface{}, error) {
-	return map[string]string{"message": string(b)}, nil
 }
 
 func (r *LotexRuler) RouteDeleteNamespaceRulesConfig(ctx *models.ReqContext) response.Response {

pkg/services/ngalert/api/lotex_prom.go

@@ -0,0 +1,51 @@
+package api
+
+import (
+	"net/http"
+
+	apimodels "github.com/grafana/alerting-api/pkg/api"
+	"github.com/grafana/grafana/pkg/api/response"
+	"github.com/grafana/grafana/pkg/infra/log"
+	"github.com/grafana/grafana/pkg/models"
+)
+
+const (
+	promRulesPath  = "/prometheus/api/v1/rules"
+	promAlertsPath = "/prometheus/api/v1/alerts"
+)
+
+type LotexProm struct {
+	log log.Logger
+	*AlertingProxy
+}
+
+func NewLotexProm(proxy *AlertingProxy, log log.Logger) *LotexProm {
+	return &LotexProm{
+		log:           log,
+		AlertingProxy: proxy,
+	}
+}
+
+func (p *LotexProm) RouteGetAlertStatuses(ctx *models.ReqContext) response.Response {
+	return p.withReq(
+		ctx, &http.Request{
+			URL: withPath(
+				*ctx.Req.URL,
+				promAlertsPath,
+			),
+		},
+		jsonExtractor(&apimodels.AlertResponse{}),
+	)
+}
+
+func (p *LotexProm) RouteGetRuleStatuses(ctx *models.ReqContext) response.Response {
+	return p.withReq(
+		ctx, &http.Request{
+			URL: withPath(
+				*ctx.Req.URL,
+				promRulesPath,
+			),
+		},
+		jsonExtractor(&apimodels.RuleResponse{}),
+	)
+}

pkg/services/ngalert/api/util.go

@@ -1,10 +1,21 @@
 package api
 
 import (
+	"bytes"
+	"encoding/json"
 	"fmt"
+	"net/http"
 	"regexp"
+	"strconv"
 
 	"github.com/go-openapi/strfmt"
+	apimodels "github.com/grafana/alerting-api/pkg/api"
+	"github.com/grafana/grafana/pkg/api/response"
+	"github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/services/datasourceproxy"
+	"github.com/grafana/grafana/pkg/services/datasources"
+	"gopkg.in/macaron.v1"
+	"gopkg.in/yaml.v3"
 )
 
 var searchRegex = regexp.MustCompile(`\{(\w+)\}`)
@@ -27,3 +38,101 @@ func stringPtr(s string) *string {
 func boolPtr(b bool) *bool {
 	return &b
 }
+
+func backendType(ctx *models.ReqContext, cache datasources.CacheService) (apimodels.Backend, error) {
+	recipient := ctx.Params("Recipient")
+	if recipient == apimodels.GrafanaBackend.String() {
+		return apimodels.GrafanaBackend, nil
+	}
+	if datasourceID, err := strconv.ParseInt(recipient, 10, 64); err == nil {
+		if ds, err := cache.GetDatasource(datasourceID, ctx.SignedInUser, ctx.SkipCache); err == nil {
+			switch ds.Type {
+			case "loki", "prometheus":
+				return apimodels.LoTexRulerBackend, nil
+			default:
+				return 0, fmt.Errorf("unexpected backend type (%v)", ds.Type)
+			}
+		}
+	}
+	return 0, fmt.Errorf("unexpected backend type (%v)", recipient)
+}
+
+// macaron unsafely asserts the http.ResponseWriter is an http.CloseNotifier, which will panic.
+// Here we impl it, which will ensure this no longer happens, but neither will we take
+// advantage cancelling upstream requests when the downstream has closed.
+// NB: http.CloseNotifier is a deprecated ifc from before the context pkg.
+type safeMacaronWrapper struct {
+	http.ResponseWriter
+}
+
+func (w *safeMacaronWrapper) CloseNotify() <-chan bool {
+	return make(chan bool)
+}
+
+// replacedResponseWriter overwrites the underlying responsewriter used by a *models.ReqContext.
+// It's ugly because it needs to replace a value behind a few nested pointers.
+func replacedResponseWriter(ctx *models.ReqContext) (*models.ReqContext, *response.NormalResponse) {
+	resp := response.CreateNormalResponse(make(http.Header), nil, 0)
+	cpy := *ctx
+	cpyMCtx := *cpy.Context
+	cpyMCtx.Resp = macaron.NewResponseWriter(ctx.Req.Method, &safeMacaronWrapper{resp})
+	cpy.Context = &cpyMCtx
+	return &cpy, resp
+}
+
+type AlertingProxy struct {
+	DataProxy *datasourceproxy.DatasourceProxyService
+}
+
+// withReq proxies a different request
+func (p *AlertingProxy) withReq(
+	ctx *models.ReqContext,
+	req *http.Request,
+	extractor func([]byte) (interface{}, error),
+) response.Response {
+	newCtx, resp := replacedResponseWriter(ctx)
+	newCtx.Req.Request = req
+	p.DataProxy.ProxyDatasourceRequestWithID(newCtx, ctx.ParamsInt64("Recipient"))
+
+	status := resp.Status()
+	if status >= 400 {
+		return response.Error(status, string(resp.Body()), nil)
+	}
+
+	t, err := extractor(resp.Body())
+	if err != nil {
+		return response.Error(500, err.Error(), nil)
+	}
+
+	b, err := json.Marshal(t)
+	if err != nil {
+		return response.Error(500, err.Error(), nil)
+	}
+
+	return response.JSON(status, b)
+}
+
+func yamlExtractor(v interface{}) func([]byte) (interface{}, error) {
+	return func(b []byte) (interface{}, error) {
+		decoder := yaml.NewDecoder(bytes.NewReader(b))
+		decoder.KnownFields(true)
+
+		err := decoder.Decode(v)
+
+		return v, err
+	}
+}
+
+func jsonExtractor(v interface{}) func([]byte) (interface{}, error) {
+	if v == nil {
+		// json unmarshal expects a pointer
+		v = &map[string]interface{}{}
+	}
+	return func(b []byte) (interface{}, error) {
+		return v, json.Unmarshal(b, v)
+	}
+}
+
+func messageExtractor(b []byte) (interface{}, error) {
+	return map[string]string{"message": string(b)}, nil
+}