Alerting: Add heuristics back to datasource healthchecks (#69329)

This commit adds heuristics back to datasource healthchecks as
it was removed in #66198. The healthcheck for Prometheus datasources
also returns the kind (Prometheus or Mimir) and a boolean if the
ruler is enabled or disabled.

pkg/tsdb/prometheus/healthcheck.go

@@ -7,9 +7,9 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	"github.com/grafana/kindsys"
 
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/tsdb/prometheus/kinds/dataquery"
 	"github.com/grafana/grafana/pkg/tsdb/prometheus/models"
@@ -28,14 +28,32 @@ func (s *Service) CheckHealth(ctx context.Context, req *backend.CheckHealthReque
 
 	// check that the datasource exists
 	if err != nil {
-		return getHealthCheckMessage(logger, "error getting datasource info", err)
+		return getHealthCheckMessage("error getting datasource info", err)
 	}
 
 	if ds == nil {
-		return getHealthCheckMessage(logger, "", errors.New("invalid datasource info received"))
+		return getHealthCheckMessage("", errors.New("invalid datasource info received"))
 	}
 
-	return healthcheck(ctx, req, ds)
+	hc, err := healthcheck(ctx, req, ds)
+	if err != nil {
+		logger.Warn("error performing prometheus healthcheck", "err", err.Error())
+		return nil, err
+	}
+
+	heuristics, err := getHeuristics(ctx, ds)
+	if err != nil {
+		logger.Warn("failed to get prometheus heuristics", "err", err.Error())
+	} else {
+		jsonDetails, err := json.Marshal(heuristics)
+		if err != nil {
+			logger.Warn("failed to marshal heuristics", "err", err)
+		} else {
+			hc.JSONDetails = jsonDetails
+		}
+	}
+
+	return hc, nil
 }
 
 func healthcheck(ctx context.Context, req *backend.CheckHealthRequest, i *instance) (*backend.CheckHealthResult, error) {
@@ -64,18 +82,18 @@ func healthcheck(ctx context.Context, req *backend.CheckHealthRequest, i *instan
 	})
 
 	if err != nil {
-		return getHealthCheckMessage(logger, "There was an error returned querying the Prometheus API.", err)
+		return getHealthCheckMessage("There was an error returned querying the Prometheus API.", err)
 	}
 
 	if resp.Responses[refID].Error != nil {
-		return getHealthCheckMessage(logger, "There was an error returned querying the Prometheus API.",
+		return getHealthCheckMessage("There was an error returned querying the Prometheus API.",
 			errors.New(resp.Responses[refID].Error.Error()))
 	}
 
-	return getHealthCheckMessage(logger, "Successfully queried the Prometheus API.", nil)
+	return getHealthCheckMessage("Successfully queried the Prometheus API.", nil)
 }
 
-func getHealthCheckMessage(logger log.Logger, message string, err error) (*backend.CheckHealthResult, error) {
+func getHealthCheckMessage(message string, err error) (*backend.CheckHealthResult, error) {
 	if err == nil {
 		return &backend.CheckHealthResult{
 			Status:  backend.HealthStatusOk,
@@ -83,7 +101,6 @@ func getHealthCheckMessage(logger log.Logger, message string, err error) (*backe
 		}, nil
 	}
 
-	logger.Warn("error performing prometheus healthcheck", "err", err.Error())
 	errorMessage := fmt.Sprintf("%s - %s", err.Error(), message)
 
 	return &backend.CheckHealthResult{

pkg/tsdb/prometheus/heuristics.go

@@ -0,0 +1,112 @@
+package prometheus
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
+)
+
+const (
+	KindPrometheus = "Prometheus"
+	KindMimir      = "Mimir"
+)
+
+var (
+	ErrNoBuildInfo = errors.New("no build info")
+)
+
+type BuildInfoRequest struct {
+	PluginContext backend.PluginContext
+}
+
+type BuildInfoResponse struct {
+	Status string                `json:"status"`
+	Data   BuildInfoResponseData `json:"data"`
+}
+
+type BuildInfoResponseData struct {
+	Version   string            `json:"version"`
+	Revision  string            `json:"revision"`
+	Branch    string            `json:"branch"`
+	Features  map[string]string `json:"features"`
+	BuildUser string            `json:"buildUser"`
+	BuildDate string            `json:"buildDate"`
+	GoVersion string            `json:"goVersion"`
+}
+
+func (s *Service) GetBuildInfo(ctx context.Context, req BuildInfoRequest) (*BuildInfoResponse, error) {
+	ds, err := s.getInstance(ctx, req.PluginContext)
+	if err != nil {
+		return nil, err
+	}
+	return getBuildInfo(ctx, ds)
+}
+
+// getBuildInfo queries /api/v1/status/buildinfo
+func getBuildInfo(ctx context.Context, i *instance) (*BuildInfoResponse, error) {
+	resp, err := i.resource.Execute(ctx, &backend.CallResourceRequest{
+		Path: "api/v1/status/buildinfo",
+	})
+	if err != nil {
+		return nil, err
+	}
+	if resp.Status == http.StatusNotFound {
+		return nil, ErrNoBuildInfo
+	}
+	if resp.Status != http.StatusOK {
+		return nil, fmt.Errorf("unexpected response %d", resp.Status)
+	}
+	res := BuildInfoResponse{}
+	if err := json.Unmarshal(resp.Body, &res); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal JSON: %w", err)
+	}
+	return &res, nil
+}
+
+type HeuristicsRequest struct {
+	PluginContext backend.PluginContext
+}
+
+type Heuristics struct {
+	Application string   `json:"application"`
+	Features    Features `json:"features"`
+}
+
+type Features struct {
+	RulerApiEnabled bool `json:"rulerApiEnabled"`
+}
+
+func (s *Service) GetHeuristics(ctx context.Context, req HeuristicsRequest) (*Heuristics, error) {
+	ds, err := s.getInstance(ctx, req.PluginContext)
+	if err != nil {
+		return nil, err
+	}
+	return getHeuristics(ctx, ds)
+}
+
+func getHeuristics(ctx context.Context, i *instance) (*Heuristics, error) {
+	heuristics := Heuristics{
+		Application: "unknown",
+		Features: Features{
+			RulerApiEnabled: false,
+		},
+	}
+	buildInfo, err := getBuildInfo(ctx, i)
+	if err != nil {
+		logger.Warn("failed to get prometheus buildinfo", "err", err.Error())
+		return nil, fmt.Errorf("failed to get buildinfo: %w", err)
+	}
+	if len(buildInfo.Data.Features) == 0 {
+		// If there are no features then this is a Prometheus datasource
+		heuristics.Application = KindPrometheus
+		heuristics.Features.RulerApiEnabled = false
+	} else {
+		heuristics.Application = KindMimir
+		heuristics.Features.RulerApiEnabled = true
+	}
+	return &heuristics, nil
+}

pkg/tsdb/prometheus/heuristics_test.go

@@ -0,0 +1,98 @@
+package prometheus
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/grafana/grafana-plugin-sdk-go/backend/datasource"
+	sdkHttpClient "github.com/grafana/grafana-plugin-sdk-go/backend/httpclient"
+	"github.com/grafana/grafana/pkg/infra/httpclient"
+	"github.com/grafana/grafana/pkg/services/featuremgmt"
+	"github.com/grafana/grafana/pkg/setting"
+)
+
+type heuristicsProvider struct {
+	httpclient.Provider
+	http.RoundTripper
+}
+
+type heuristicsSuccessRoundTripper struct {
+	res    io.ReadCloser
+	status int
+}
+
+func (rt *heuristicsSuccessRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	return &http.Response{
+		Status:        strconv.Itoa(rt.status),
+		StatusCode:    rt.status,
+		Header:        nil,
+		Body:          rt.res,
+		ContentLength: 0,
+		Request:       req,
+	}, nil
+}
+
+func (provider *heuristicsProvider) New(opts ...sdkHttpClient.Options) (*http.Client, error) {
+	client := &http.Client{}
+	client.Transport = provider.RoundTripper
+	return client, nil
+}
+
+func (provider *heuristicsProvider) GetTransport(opts ...sdkHttpClient.Options) (http.RoundTripper, error) {
+	return provider.RoundTripper, nil
+}
+
+func getHeuristicsMockProvider(rt http.RoundTripper) *heuristicsProvider {
+	return &heuristicsProvider{
+		RoundTripper: rt,
+	}
+}
+
+func Test_GetHeuristics(t *testing.T) {
+	t.Run("should return Prometheus", func(t *testing.T) {
+		rt := heuristicsSuccessRoundTripper{
+			res:    io.NopCloser(strings.NewReader("{\"status\":\"success\",\"data\":{\"version\":\"1.0\"}}")),
+			status: http.StatusOK,
+		}
+		httpProvider := getHeuristicsMockProvider(&rt)
+		s := &Service{
+			im: datasource.NewInstanceManager(newInstanceSettings(httpProvider, &setting.Cfg{}, &featuremgmt.FeatureManager{}, nil)),
+		}
+
+		req := HeuristicsRequest{
+			PluginContext: getPluginContext(),
+		}
+		res, err := s.GetHeuristics(context.Background(), req)
+		assert.NoError(t, err)
+		require.NotNil(t, res)
+		assert.Equal(t, KindPrometheus, res.Application)
+		assert.Equal(t, Features{RulerApiEnabled: false}, res.Features)
+	})
+
+	t.Run("should return Mimir", func(t *testing.T) {
+		rt := heuristicsSuccessRoundTripper{
+			res:    io.NopCloser(strings.NewReader("{\"status\":\"success\",\"data\":{\"features\":{\"foo\":\"bar\"},\"version\":\"1.0\"}}")),
+			status: http.StatusOK,
+		}
+		httpProvider := getHeuristicsMockProvider(&rt)
+		s := &Service{
+			im: datasource.NewInstanceManager(newInstanceSettings(httpProvider, &setting.Cfg{}, &featuremgmt.FeatureManager{}, nil)),
+		}
+
+		req := HeuristicsRequest{
+			PluginContext: getPluginContext(),
+		}
+		res, err := s.GetHeuristics(context.Background(), req)
+		assert.NoError(t, err)
+		require.NotNil(t, res)
+		assert.Equal(t, KindMimir, res.Application)
+		assert.Equal(t, Features{RulerApiEnabled: true}, res.Features)
+	})
+}