fix otel instrumentation

Author: cedi

src/go.mod

@@ -13,6 +13,8 @@ require (
 	github.com/spf13/cobra v1.9.1
 	github.com/spf13/viper v1.20.1
 	go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin v0.60.0
+	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.60.0
+	go.opentelemetry.io/otel v1.35.0
 	go.opentelemetry.io/otel/trace v1.35.0
 	go.uber.org/zap v1.27.0
 	google.golang.org/grpc v1.72.0
@@ -63,7 +65,6 @@ require (
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/ugorji/go/codec v1.2.12 // indirect
 	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
-	go.opentelemetry.io/otel v1.35.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc v0.11.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp v0.11.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.35.0 // indirect

src/go.sum

@@ -146,6 +146,8 @@ go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJyS
 go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
 go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin v0.60.0 h1:jj/B7eX95/mOxim9g9laNZkOHKz/XCHG0G410SntRy4=
 go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin v0.60.0/go.mod h1:ZvRTVaYYGypytG0zRp2A60lpj//cMq3ZnxYdZaljVBM=
+go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.60.0 h1:x7wzEgXfnzJcHDwStJT+mxOz4etr2EcexjqhBvmoakw=
+go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.60.0/go.mod h1:rg+RlpR5dKwaS95IyyZqj5Wd4E13lk/msnTS0Xl9lJM=
 go.opentelemetry.io/otel v1.35.0 h1:xKWKPxrxB6OtMCbmMY021CqC45J+3Onta9MqjhnusiQ=
 go.opentelemetry.io/otel v1.35.0/go.mod h1:UEqy8Zp11hpkUrL73gSlELM0DupHoiq72dR+Zqel/+Y=
 go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc v0.11.0 h1:HMUytBT3uGhPKYY/u/G5MR9itrlSO2SMOsSD3Tk3k7A=

src/pkg/api/grpc_api.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/spechtlabs/go-otel-utils/otelzap"
 	"github.com/spf13/viper"
+	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
 
@@ -23,9 +24,14 @@ type GrpcApi struct {
 }
 
 func NewGrpcApiServer(client *client.ICalClient) *GrpcApi {
+	// Create a server with the OpenTelemetry interceptor
+	srv := grpc.NewServer(
+		grpc.StatsHandler(otelgrpc.NewServerHandler()),
+	)
+
 	e := &GrpcApi{
 		client: client,
-		srv:    grpc.NewServer(),
+		srv:    srv,
 	}
 
 	pb.RegisterCalenderServiceServer(e.srv, e)
@@ -42,9 +48,13 @@ func NewGrpcApiServer(client *client.ICalClient) *GrpcApi {
 }
 
 func NewGrpcApiClient(addr string) (*grpc.ClientConn, pb.CalenderServiceClient) {
+	// Set up a connection to the server with OpenTelemetry instrumentation
+	conn, err := grpc.NewClient(
+		addr,
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
+		grpc.WithStatsHandler(otelgrpc.NewClientHandler()),
+	)
 
-	// Set up a connection to the server.
-	conn, err := grpc.NewClient(addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
 	if err != nil {
 		otelzap.L().Fatal(fmt.Sprintf("gRPC API: failed to connect: %v", err))
 	}

src/pkg/client/ical_client.go

@@ -16,6 +16,10 @@ import (
 	"github.com/apognu/gocal"
 	"github.com/spechtlabs/go-otel-utils/otelzap"
 	"github.com/spf13/viper"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
 	"go.uber.org/zap"
 
 	pb "github.com/SpechtLabs/CalendarAPI/pkg/protos"
@@ -25,6 +29,7 @@ type ICalClient struct {
 	cacheMux        sync.RWMutex
 	cache           *pb.CalendarResponse
 	cacheExpiration time.Time
+	tracer          trace.Tracer
 
 	statusMux    sync.RWMutex
 	CustomStatus map[string]*pb.CustomStatus // custom status is a map from calendar-name to status
@@ -79,10 +84,14 @@ func NewICalClient() *ICalClient {
 		cacheExpiration: time.Now(),
 		cache:           &pb.CalendarResponse{LastUpdated: time.Now().Unix()},
 		CustomStatus:    make(map[string]*pb.CustomStatus),
+		tracer:          otel.GetTracerProvider().Tracer("github.com/SpechtLabs/CalendarAPI/pkg/client"),
 	}
 }
 
 func (e *ICalClient) FetchEvents(ctx context.Context) {
+	ctx, span := e.tracer.Start(ctx, "ICalClient.FetchEvents")
+	defer span.End()
+
 	response := &pb.CalendarResponse{
 		LastUpdated: time.Now().Unix(),
 		Entries:     make([]*pb.CalendarEntry, 0),
@@ -127,6 +136,9 @@ func (e *ICalClient) FetchEvents(ctx context.Context) {
 }
 
 func (e *ICalClient) GetEvents(ctx context.Context) *pb.CalendarResponse {
+	ctx, span := e.tracer.Start(ctx, "ICalClient.GetEvents")
+	defer span.End()
+
 	if e.cache == nil {
 		otelzap.L().Ctx(ctx).Sugar().Infow("Experiencing cold. Fetching events now!")
 		e.FetchEvents(ctx)
@@ -138,6 +150,9 @@ func (e *ICalClient) GetEvents(ctx context.Context) *pb.CalendarResponse {
 }
 
 func (e *ICalClient) GetCurrentEvent(ctx context.Context, calendar string) *pb.CalendarEntry {
+	ctx, span := e.tracer.Start(ctx, "ICalClient.GetCurrentEvent")
+	defer span.End()
+
 	if e.cache == nil {
 		otelzap.L().Ctx(ctx).Sugar().Infow("Experiencing cold. Fetching events now!")
 		e.FetchEvents(ctx)
@@ -186,7 +201,10 @@ func (e *ICalClient) GetCurrentEvent(ctx context.Context, calendar string) *pb.C
 	return closest
 }
 
-func (e *ICalClient) GetCustomStatus(_ context.Context, req *pb.GetCustomStatusRequest) *pb.CustomStatus {
+func (e *ICalClient) GetCustomStatus(ctx context.Context, req *pb.GetCustomStatusRequest) *pb.CustomStatus {
+	ctx, span := e.tracer.Start(ctx, "ICalClient.GetCustomStatus")
+	defer span.End()
+
 	e.statusMux.RLock()
 	defer e.statusMux.RUnlock()
 
@@ -197,14 +215,26 @@ func (e *ICalClient) GetCustomStatus(_ context.Context, req *pb.GetCustomStatusR
 	return &pb.CustomStatus{}
 }
 
-func (e *ICalClient) SetCustomStatus(_ context.Context, req *pb.SetCustomStatusRequest) {
+func (e *ICalClient) SetCustomStatus(ctx context.Context, req *pb.SetCustomStatusRequest) {
+	ctx, span := e.tracer.Start(ctx, "ICalClient.SetCustomStatus")
+	defer span.End()
+
 	e.statusMux.Lock()
 	defer e.statusMux.Unlock()
 
 	e.CustomStatus[req.CalendarName] = req.Status
 }
 
 func (e *ICalClient) loadEvents(ctx context.Context, calName string, from string, url string, rules []Rule) ([]*pb.CalendarEntry, *errors.ResolvingError) {
+	ctx, span := e.tracer.Start(ctx, "ICalClient.loadEvents")
+	defer span.End()
+
+	span.SetAttributes(
+		attribute.String("calendar.name", calName),
+		attribute.String("calendar.from", from),
+		attribute.String("calendar.url", url),
+	)
+
 	ical, err := e.getIcal(ctx, from, url)
 	if ical == nil || err != nil {
 		return nil, errors.Wrap(err, fmt.Errorf("failed to load iCal calendar file"), "")
@@ -328,14 +358,25 @@ func (e *ICalClient) getIcalFromFile(path string) (io.ReadCloser, *errors.Resolv
 }
 
 func (e *ICalClient) getIcalFromURL(ctx context.Context, url string) (io.ReadCloser, *errors.ResolvingError) {
-	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	ctx, span := e.tracer.Start(ctx, "ICalClient.getIcalFromURL")
+	defer span.End()
+
+	span.SetAttributes(
+		attribute.String("http.method", http.MethodGet),
+	)
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
 	if err != nil {
+		span.RecordError(err)
+		span.SetStatus(codes.Error, err.Error())
 		return nil, errors.NewResolvingError(fmt.Errorf("failed creating request for %s: %w", url, err), "")
 	}
 
 	client := http.DefaultClient
 	resp, err := client.Do(req)
 	if err != nil {
+		span.RecordError(err)
+		span.SetStatus(codes.Error, err.Error())
 		return nil, errors.NewResolvingError(fmt.Errorf("failed making request to %s: %w", url, err), "verify if URL exists and is accessible")
 	}