Enabling Opencensus

Gopkg.toml

[[constraint]]
  name = "go.opencensus.io"
  version = "0.17.0"

httpclient.go

client := &http.Client{
    Transport: &ochttp.Transport{},
}

// Use client to perform requests.
_ = client

jaeger.go

traceExporter, err := jaeger.NewExporter(jaeger.Options{
    AgentEndpoint: globalConfig.ToJaegerAddress(), // localhost:1234
    ServiceName:   "my-service",
})
if err != nil {
    log.WithError(err).Warn("failed to create trace jaeger exporter")
} else {
    defer traceExporter.Flush()
    trace.RegisterExporter(traceExporter)
    trace.ApplyConfig(trace.Config{DefaultSampler: trace.ProbabilitySampler(globalConfig.Jaeger.SamplerParam)}) // `0.1`
}

main.go

import (
	"go.opencensus.io/exporter/jaeger"
	"go.opencensus.io/exporter/prometheus"
	"go.opencensus.io/plugin/ochttp"
	"go.opencensus.io/stats/view"
	"go.opencensus.io/tag"
	"go.opencensus.io/trace"
)

promExporter, err := prometheus.NewExporter(prometheus.Options{Namespace: "my_service"})
if err != nil {
    log.WithError(err).Warn("failed to create stats prom exporter")
} else {
    view.RegisterExporter(promExporter)
    view.SetReportingPeriod(time.Second)
}

// Registering Default OC Views for the HTTP Server

// ATM by default OC does not expose server_latency_by_path 
ochttp.DefaultServerViews = append(ochttp.DefaultServerViews, &view.View{
		Name:        "opencensus_io_http_server_latency_by_path",
		TagKeys:     []tag.Key{ochttp.KeyServerRoute},
		Measure:     ochttp.ServerLatency,
		Aggregation: ochttp.DefaultLatencyDistribution,
})
if err := view.Register(ochttp.DefaultServerViews...); err != nil {
    log.WithError(err).Warn("failed to register view stats")
}

// Registering Default OC Views for the HTTP Client

ochttp.DefaultClientViews = append(ochttp.DefaultClientViews, &view.View{
    Name:        "opencensus_io_http_client_latency_by_path",
    TagKeys:     []tag.Key{ochttp.Path},
		Measure:     ochttp.ClientLatency,
		Aggregation: ochttp.DefaultLatencyDistribution,
})

if err := view.Register(ochttp.DefaultClientViews...); err != nil {
    log.WithError(err).Warn("failed to register view stats")
}

// Expose metrics endpoint

router.Handle("/metrics", promExporter)

// Wrap routers to keep cardinality low

path := "/users/{id}"
router.Route(path, func(r chi.Router) {
		r.Method(http.MethodGet, "/", ochttp.WithRouteTag(handler.UsersShow, path))
})

values-env.yaml

services:
  api:
    enabled: true
    enablePrometheus: true
    type: ClusterIP
    
provisionDashboards:
  enabled: true
  dashboardLabel: grafana_dashboard