mirror of https://github.com/grafana/grafana
Loki: Add backend healthcheck (#74330)
* add loki healthcheck * remove `testDatasource` call * remove unused error check * change success message * improve error messagespull/74359/head
Sven Grossmann
2 years ago
committed by
GitHub
parent
ed46e3444c
commit
a403027608
@ -0,0 +1,104 @@ |
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package loki |
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import ( |
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"context" |
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"encoding/json" |
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"errors" |
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"fmt" |
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"time" |
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"github.com/grafana/grafana-plugin-sdk-go/backend" |
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"github.com/grafana/grafana/pkg/infra/log" |
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"github.com/grafana/grafana/pkg/tsdb/loki/kinds/dataquery" |
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) |
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const ( |
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refID = "__healthcheck__" |
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) |
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func (s *Service) CheckHealth(ctx context.Context, req *backend.CheckHealthRequest) (*backend.CheckHealthResult, |
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error) { |
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logger := s.logger.New("endpoint", "CheckHealth") |
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ds, err := s.im.Get(ctx, req.PluginContext) |
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// check that the datasource exists
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if err != nil { |
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return getHealthCheckMessage(fmt.Errorf("failed to get datasource information: %w", err), logger), err |
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} |
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if ds == nil { |
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return getHealthCheckMessage(errors.New("invalid datasource info received"), logger), err |
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} |
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hc := healthcheck(ctx, req, s, logger) |
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return hc, nil |
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} |
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func healthcheck(ctx context.Context, req *backend.CheckHealthRequest, s *Service, logger *log.ConcreteLogger) *backend.CheckHealthResult { |
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step := "1s" |
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qt := "instant" |
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qm := dataquery.LokiDataQuery{ |
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Expr: "vector(1)+vector(1)", |
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Step: &step, |
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QueryType: &qt, |
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} |
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b, _ := json.Marshal(&qm) |
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query := backend.DataQuery{ |
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RefID: refID, |
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TimeRange: backend.TimeRange{ |
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From: time.Unix(1, 0).UTC(), |
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To: time.Unix(4, 0).UTC(), |
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}, |
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JSON: b, |
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} |
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resp, err := s.QueryData(ctx, &backend.QueryDataRequest{ |
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PluginContext: req.PluginContext, |
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Queries: []backend.DataQuery{query}, |
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}) |
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if err != nil { |
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return getHealthCheckMessage(fmt.Errorf("error received while querying loki: %w", err), logger) |
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} |
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if resp.Responses[refID].Error != nil { |
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return getHealthCheckMessage(fmt.Errorf("error from loki: %w", resp.Responses[refID].Error), logger) |
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} |
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frameLen := len(resp.Responses[refID].Frames) |
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if frameLen != 1 { |
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return getHealthCheckMessage(fmt.Errorf("invalid dataframe length, expected %d got %d", 1, frameLen), logger) |
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} |
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fieldLen := len(resp.Responses[refID].Frames[0].Fields) |
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if fieldLen != 2 { |
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return getHealthCheckMessage(fmt.Errorf("invalid dataframe field length, expected %d got %d", 2, fieldLen), logger) |
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} |
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fieldValueLen := resp.Responses[refID].Frames[0].Fields[0].Len() |
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if fieldValueLen != 1 { |
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return getHealthCheckMessage(fmt.Errorf("invalid dataframe field value length, expected %d got %d", 1, fieldLen), logger) |
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} |
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rspValue := resp.Responses[refID].Frames[0].Fields[1].At(0).(float64) |
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if rspValue != 2 { |
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return getHealthCheckMessage(fmt.Errorf("invalid response value, expected %d got %f", 2, rspValue), logger) |
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} |
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return getHealthCheckMessage(nil, logger) |
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} |
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func getHealthCheckMessage(err error, logger *log.ConcreteLogger) *backend.CheckHealthResult { |
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if err == nil { |
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return &backend.CheckHealthResult{ |
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Status: backend.HealthStatusOk, |
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Message: "Data source successfully connected.", |
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} |
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} |
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logger.Error("Loki health check failed", "error", err) |
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return &backend.CheckHealthResult{ |
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Status: backend.HealthStatusError, |
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Message: "Unable to connect with Loki. Please check the server logs for more details.", |
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} |
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} |
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@ -0,0 +1,145 @@ |
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package loki |
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import ( |
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"context" |
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"io" |
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"net/http" |
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"strings" |
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"testing" |
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"time" |
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"github.com/grafana/grafana-plugin-sdk-go/backend" |
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"github.com/grafana/grafana-plugin-sdk-go/backend/datasource" |
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sdkHttpClient "github.com/grafana/grafana-plugin-sdk-go/backend/httpclient" |
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"github.com/grafana/grafana/pkg/infra/httpclient" |
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"github.com/grafana/grafana/pkg/infra/log" |
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"github.com/grafana/grafana/pkg/infra/tracing" |
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"github.com/grafana/grafana/pkg/services/featuremgmt" |
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"github.com/stretchr/testify/assert" |
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) |
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type healthCheckProvider[T http.RoundTripper] struct { |
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httpclient.Provider |
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RoundTripper *T |
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} |
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type healthCheckSuccessRoundTripper struct { |
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} |
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type healthCheckFailRoundTripper struct { |
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} |
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func (rt *healthCheckSuccessRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) { |
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return &http.Response{ |
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Status: "200", |
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StatusCode: 200, |
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Header: nil, |
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Body: io.NopCloser(strings.NewReader(`{ |
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"data": { |
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"resultType": "vector", |
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"result": [ |
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{ |
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"metric": {}, |
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"value": [ |
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4000000000, |
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"2" |
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] |
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} |
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] |
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}, |
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"status": "success" |
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}`)), |
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ContentLength: 0, |
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Request: req, |
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}, nil |
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} |
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func (rt *healthCheckFailRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) { |
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return &http.Response{ |
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Status: "400", |
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StatusCode: 400, |
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Header: nil, |
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Body: nil, |
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ContentLength: 0, |
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Request: req, |
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}, nil |
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} |
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func (provider *healthCheckProvider[T]) New(opts ...sdkHttpClient.Options) (*http.Client, error) { |
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client := &http.Client{} |
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provider.RoundTripper = new(T) |
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client.Transport = *provider.RoundTripper |
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return client, nil |
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} |
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func (provider *healthCheckProvider[T]) GetTransport(opts ...sdkHttpClient.Options) (http.RoundTripper, error) { |
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return *new(T), nil |
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} |
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func getMockProvider[T http.RoundTripper]() *healthCheckProvider[T] { |
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return &healthCheckProvider[T]{ |
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RoundTripper: new(T), |
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} |
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} |
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func Test_healthcheck(t *testing.T) { |
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t.Run("should do a successful health check", func(t *testing.T) { |
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httpProvider := getMockProvider[*healthCheckSuccessRoundTripper]() |
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s := &Service{ |
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im: datasource.NewInstanceManager(newInstanceSettings(httpProvider)), |
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features: featuremgmt.WithFeatures(featuremgmt.FlagLokiLogsDataplane, featuremgmt.FlagLokiMetricDataplane), |
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tracer: tracing.NewFakeTracer(), |
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logger: log.New("loki test"), |
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} |
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req := &backend.CheckHealthRequest{ |
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PluginContext: getPluginContext(), |
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Headers: nil, |
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} |
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res, err := s.CheckHealth(context.Background(), req) |
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assert.NoError(t, err) |
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assert.Equal(t, backend.HealthStatusOk, res.Status) |
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}) |
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t.Run("should return an error for an unsuccessful health check", func(t *testing.T) { |
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httpProvider := getMockProvider[*healthCheckFailRoundTripper]() |
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s := &Service{ |
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im: datasource.NewInstanceManager(newInstanceSettings(httpProvider)), |
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features: featuremgmt.WithFeatures(featuremgmt.FlagLokiLogsDataplane, featuremgmt.FlagLokiMetricDataplane), |
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tracer: tracing.NewFakeTracer(), |
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logger: log.New("loki test"), |
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} |
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req := &backend.CheckHealthRequest{ |
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PluginContext: getPluginContext(), |
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Headers: nil, |
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} |
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res, err := s.CheckHealth(context.Background(), req) |
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assert.NoError(t, err) |
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assert.Equal(t, backend.HealthStatusError, res.Status) |
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}) |
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} |
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func getPluginContext() backend.PluginContext { |
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return backend.PluginContext{ |
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OrgID: 0, |
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PluginID: "loki", |
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User: nil, |
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AppInstanceSettings: nil, |
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DataSourceInstanceSettings: &backend.DataSourceInstanceSettings{ |
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ID: 0, |
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UID: "", |
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Type: "loki", |
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Name: "test-loki", |
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URL: "http://loki:3100", |
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User: "", |
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Database: "", |
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BasicAuthEnabled: true, |
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BasicAuthUser: "admin", |
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JSONData: []byte("{}"), |
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DecryptedSecureJSONData: map[string]string{}, |
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Updated: time.Time{}, |
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}, |
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} |
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} |
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