Add OpenTelemetry instrumentation with middleware-only approach

2026-04-04 12:19:48 +02:00
parent c38d7c6d76
commit 36f0b79b90
13 changed files with 452 additions and 46 deletions
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -11,8 +11,10 @@ import (

 	"DanceLessonsCoach/pkg/config"
 	"DanceLessonsCoach/pkg/server"
+	"DanceLessonsCoach/pkg/telemetry"
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 )

 func main() {
@@ -50,6 +52,27 @@ func main() {

 	log.Info().Bool("json_logging", cfg.Logging.JSON).Msg("Logging configured")

+	// Initialize OpenTelemetry if enabled
+	var tracerProvider *sdktrace.TracerProvider
+	if cfg.GetTelemetryEnabled() {
+		log.Info().Msg("Initializing OpenTelemetry tracing")
+
+		telemetrySetup := &telemetry.Setup{
+			ServiceName:  cfg.GetServiceName(),
+			OTLPEndpoint: cfg.GetOTLPEndpoint(),
+			Insecure:     cfg.GetTelemetryInsecure(),
+			SamplerType:  cfg.GetSamplerType(),
+			SamplerRatio: cfg.GetSamplerRatio(),
+		}
+
+		var err error
+		if tracerProvider, err = telemetrySetup.InitializeTracing(context.Background()); err != nil {
+			log.Error().Err(err).Msg("Failed to initialize OpenTelemetry, continuing without tracing")
+		} else {
+			log.Info().Msg("OpenTelemetry tracing initialized successfully")
+		}
+	}
+
 	// Setup signal context for graceful shutdown
 	rootCtx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
 	defer stop()
@@ -116,6 +139,15 @@ func main() {
 		serverStop()
 		log.Info().Msg("Server exited")

+		// Shutdown OpenTelemetry tracer provider
+		if tracerProvider != nil {
+			if err := telemetry.Shutdown(context.Background(), tracerProvider); err != nil {
+				log.Error().Err(err).Msg("Failed to shutdown OpenTelemetry tracer provider")
+			} else {
+				log.Info().Msg("OpenTelemetry tracer provider shutdown complete")
+			}
+		}
+
 		// Force log flush by writing to stderr directly
 		// This ensures logs are written before process exits
 		time.Sleep(100 * time.Millisecond)
--- a/config.example.yaml
+++ b/config.example.yaml
@@ -22,9 +22,40 @@ logging:
  # When true, logs are output in JSON format instead of console format
  json: false

+# Telemetry configuration (OpenTelemetry)
+telemetry:
+  # Enable OpenTelemetry tracing (default: false)
+  enabled: false
+  
+  # OTLP endpoint for trace export (default: "localhost:4317")
+  # Format: host:port
+  otlp_endpoint: "localhost:4317"
+  
+  # Service name for tracing (default: "DanceLessonsCoach")
+  service_name: "DanceLessonsCoach"
+  
+  # Use insecure connection (no TLS) (default: true)
+  insecure: true
+  
+  # Sampler configuration
+  sampler:
+    # Sampler type (default: "parentbased_always_on")
+    # Options: "always_on", "always_off", "traceidratio", "parentbased_always_on", "parentbased_always_off", "parentbased_traceidratio"
+    type: "parentbased_always_on"
+    
+    # Sampling ratio (0.0 to 1.0, default: 1.0)
+    # Only used with traceidratio and parentbased_traceidratio samplers
+    ratio: 1.0
+
 # Environment Variables
 # You can also configure via environment variables with DLC_ prefix:
 # DLC_SERVER_HOST=0.0.0.0
 # DLC_SERVER_PORT=8080
 # DLC_SHUTDOWN_TIMEOUT=30s
 # DLC_LOGGING_JSON=false
+# DLC_TELEMETRY_ENABLED=true
+# DLC_TELEMETRY_OTLP_ENDPOINT="jaeger:4317"
+# DLC_TELEMETRY_SERVICE_NAME="DanceLessonsCoach"
+# DLC_TELEMETRY_INSECURE=true
+# DLC_TELEMETRY_SAMPLER_TYPE="parentbased_always_on"
+# DLC_TELEMETRY_SAMPLER_RATIO=1.0
--- a/go.mod
+++ b/go.mod
@@ -3,9 +3,16 @@ module DanceLessonsCoach
 go 1.26.1

 require (
+	github.com/cenkalti/backoff/v5 v5.0.3 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/fsnotify/fsnotify v1.9.0 // indirect
 	github.com/go-chi/chi/v5 v5.2.5 // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/go-viper/mapstructure/v2 v2.4.0 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.28.0 // indirect
 	github.com/mattn/go-colorable v0.1.14 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
@@ -17,7 +24,21 @@ require (
 	github.com/spf13/pflag v1.0.10 // indirect
 	github.com/spf13/viper v1.21.0 // indirect
 	github.com/subosito/gotenv v1.6.0 // indirect
+	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.67.0 // indirect
+	go.opentelemetry.io/otel v1.43.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.43.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.43.0 // indirect
+	go.opentelemetry.io/otel/metric v1.43.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.43.0 // indirect
+	go.opentelemetry.io/otel/trace v1.43.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.10.0 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
+	golang.org/x/net v0.52.0 // indirect
 	golang.org/x/sys v0.42.0 // indirect
-	golang.org/x/text v0.28.0 // indirect
+	golang.org/x/text v0.35.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 // indirect
+	google.golang.org/grpc v1.80.0 // indirect
+	google.golang.org/protobuf v1.36.11 // indirect
 )
--- a/go.sum
+++ b/go.sum
@@ -1,9 +1,24 @@
+github.com/cenkalti/backoff/v5 v5.0.3 h1:ZN+IMa753KfX5hd8vVaMixjnqRZ3y8CuJKRKj1xcsSM=
+github.com/cenkalti/backoff/v5 v5.0.3/go.mod h1:rkhZdG3JZukswDf7f0cwqPNk4K0sa+F97BxZthm/crw=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
+github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/fsnotify/fsnotify v1.9.0 h1:2Ml+OJNzbYCTzsxtv8vKSFD9PbJjmhYF14k/jKC7S9k=
 github.com/fsnotify/fsnotify v1.9.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
 github.com/go-chi/chi/v5 v5.2.5 h1:Eg4myHZBjyvJmAFjFvWgrqDTXFyOzjj7YIm3L3mu6Ug=
 github.com/go-chi/chi/v5 v5.2.5/go.mod h1:X7Gx4mteadT3eDOMTsXzmI4/rwUpOwBHLpAfupzFJP0=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
+github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
 github.com/go-viper/mapstructure/v2 v2.4.0 h1:EBsztssimR/CONLSZZ04E8qAkxNYq4Qp9LvH92wZUgs=
 github.com/go-viper/mapstructure/v2 v2.4.0/go.mod h1:oJDH3BJKyqBA2TXFhDsKDGDTlndYOZ6rGS0BRZIxGhM=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.28.0 h1:HWRh5R2+9EifMyIHV7ZV+MIZqgz+PMpZ14Jynv3O2Zs=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.28.0/go.mod h1:JfhWUomR1baixubs02l85lZYYOm7LV6om4ceouMv45c=
 github.com/mattn/go-colorable v0.1.14 h1:9A9LHSqF/7dyVVX6g0U9cwm9pG3kP9gSzcuIPHPsaIE=
 github.com/mattn/go-colorable v0.1.14/go.mod h1:6LmQG8QLFO4G5z1gPvYEzlUgJ2wF+stgPZH1UqBm1s8=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
@@ -26,11 +41,41 @@ github.com/spf13/viper v1.21.0 h1:x5S+0EU27Lbphp4UKm1C+1oQO+rKx36vfCoaVebLFSU=
 github.com/spf13/viper v1.21.0/go.mod h1:P0lhsswPGWD/1lZJ9ny3fYnVqxiegrlNrEmgLjbTCAY=
 github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8=
 github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
+go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
+go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.67.0 h1:OyrsyzuttWTSur2qN/Lm0m2a8yqyIjUVBZcxFPuXq2o=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.67.0/go.mod h1:C2NGBr+kAB4bk3xtMXfZ94gqFDtg/GkI7e9zqGh5Beg=
+go.opentelemetry.io/otel v1.43.0 h1:mYIM03dnh5zfN7HautFE4ieIig9amkNANT+xcVxAj9I=
+go.opentelemetry.io/otel v1.43.0/go.mod h1:JuG+u74mvjvcm8vj8pI5XiHy1zDeoCS2LB1spIq7Ay0=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.43.0 h1:88Y4s2C8oTui1LGM6bTWkw0ICGcOLCAI5l6zsD1j20k=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.43.0/go.mod h1:Vl1/iaggsuRlrHf/hfPJPvVag77kKyvrLeD10kpMl+A=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.43.0 h1:RAE+JPfvEmvy+0LzyUA25/SGawPwIUbZ6u0Wug54sLc=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.43.0/go.mod h1:AGmbycVGEsRx9mXMZ75CsOyhSP6MFIcj/6dnG+vhVjk=
+go.opentelemetry.io/otel/metric v1.43.0 h1:d7638QeInOnuwOONPp4JAOGfbCEpYb+K6DVWvdxGzgM=
+go.opentelemetry.io/otel/metric v1.43.0/go.mod h1:RDnPtIxvqlgO8GRW18W6Z/4P462ldprJtfxHxyKd2PY=
+go.opentelemetry.io/otel/sdk v1.43.0 h1:pi5mE86i5rTeLXqoF/hhiBtUNcrAGHLKQdhg4h4V9Dg=
+go.opentelemetry.io/otel/sdk v1.43.0/go.mod h1:P+IkVU3iWukmiit/Yf9AWvpyRDlUeBaRg6Y+C58QHzg=
+go.opentelemetry.io/otel/trace v1.43.0 h1:BkNrHpup+4k4w+ZZ86CZoHHEkohws8AY+WTX09nk+3A=
+go.opentelemetry.io/otel/trace v1.43.0/go.mod h1:/QJhyVBUUswCphDVxq+8mld+AvhXZLhe+8WVFxiFff0=
+go.opentelemetry.io/proto/otlp v1.10.0 h1:IQRWgT5srOCYfiWnpqUYz9CVmbO8bFmKcwYxpuCSL2g=
+go.opentelemetry.io/proto/otlp v1.10.0/go.mod h1:/CV4QoCR/S9yaPj8utp3lvQPoqMtxXdzn7ozvvozVqk=
 go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
+golang.org/x/net v0.52.0 h1:He/TN1l0e4mmR3QqHMT2Xab3Aj3L9qjbhRm78/6jrW0=
+golang.org/x/net v0.52.0/go.mod h1:R1MAz7uMZxVMualyPXb+VaqGSa3LIaUqk0eEt3w36Sw=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
 golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/text v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
 golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
+golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
+golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
+google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9 h1:VPWxll4HlMw1Vs/qXtN7BvhZqsS9cdAittCNvVENElA=
+google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9/go.mod h1:7QBABkRtR8z+TEnmXTqIqwJLlzrZKVfAUm7tY3yGv0M=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 h1:m8qni9SQFH0tJc1X0vmnpw/0t+AImlSvp30sEupozUg=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
+google.golang.org/grpc v1.80.0 h1:Xr6m2WmWZLETvUNvIUmeD5OAagMw3FiKmMlTdViWsHM=
+google.golang.org/grpc v1.80.0/go.mod h1:ho/dLnxwi3EDJA4Zghp7k2Ec1+c2jqup0bFkw07bwF4=
+google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
+google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -11,16 +11,41 @@ import (

 // Config represents the application configuration
 type Config struct {
-	Server struct {
+	Server    ServerConfig    `mapstructure:"server"`
+	Shutdown  ShutdownConfig  `mapstructure:"shutdown"`
+	Logging   LoggingConfig   `mapstructure:"logging"`
+	Telemetry TelemetryConfig `mapstructure:"telemetry"`
+}
+
+// ServerConfig holds server-related configuration
+type ServerConfig struct {
 	Host string `mapstructure:"host"`
 	Port int    `mapstructure:"port"`
-	}
-	Shutdown struct {
+}
+
+// ShutdownConfig holds shutdown-related configuration
+type ShutdownConfig struct {
 	Timeout time.Duration `mapstructure:"timeout"`
-	}
-	Logging struct {
+}
+
+// LoggingConfig holds logging-related configuration
+type LoggingConfig struct {
 	JSON bool `mapstructure:"json"`
-	}
+}
+
+// TelemetryConfig holds OpenTelemetry-related configuration
+type TelemetryConfig struct {
+	Enabled      bool          `mapstructure:"enabled"`
+	OTLPEndpoint string        `mapstructure:"otlp_endpoint"`
+	ServiceName  string        `mapstructure:"service_name"`
+	Insecure     bool          `mapstructure:"insecure"`
+	Sampler      SamplerConfig `mapstructure:"sampler"`
+}
+
+// SamplerConfig holds tracing sampler configuration
+type SamplerConfig struct {
+	Type  string  `mapstructure:"type"`
+	Ratio float64 `mapstructure:"ratio"`
 }

 // LoadConfig loads configuration from file, environment variables, and defaults
@@ -35,6 +60,14 @@ func LoadConfig() (*Config, error) {
 	v.SetDefault("shutdown.timeout", 30*time.Second)
 	v.SetDefault("logging.json", false)

+	// Telemetry defaults
+	v.SetDefault("telemetry.enabled", false)
+	v.SetDefault("telemetry.otlp_endpoint", "localhost:4317")
+	v.SetDefault("telemetry.service_name", "DanceLessonsCoach")
+	v.SetDefault("telemetry.insecure", true)
+	v.SetDefault("telemetry.sampler.type", "parentbased_always_on")
+	v.SetDefault("telemetry.sampler.ratio", 1.0)
+
 	// Check for custom config file path via environment variable
 	if configFile := os.Getenv("DLC_CONFIG_FILE"); configFile != "" {
 		v.SetConfigFile(configFile)
@@ -65,6 +98,14 @@ func LoadConfig() (*Config, error) {
 	v.BindEnv("shutdown.timeout", "DLC_SHUTDOWN_TIMEOUT")
 	v.BindEnv("logging.json", "DLC_LOGGING_JSON")

+	// Telemetry environment variables
+	v.BindEnv("telemetry.enabled", "DLC_TELEMETRY_ENABLED")
+	v.BindEnv("telemetry.otlp_endpoint", "DLC_TELEMETRY_OTLP_ENDPOINT")
+	v.BindEnv("telemetry.service_name", "DLC_TELEMETRY_SERVICE_NAME")
+	v.BindEnv("telemetry.insecure", "DLC_TELEMETRY_INSECURE")
+	v.BindEnv("telemetry.sampler.type", "DLC_TELEMETRY_SAMPLER_TYPE")
+	v.BindEnv("telemetry.sampler.ratio", "DLC_TELEMETRY_SAMPLER_RATIO")
+
 	// Unmarshal into Config struct
 	var config Config
 	if err := v.Unmarshal(&config); err != nil {
@@ -77,6 +118,8 @@ func LoadConfig() (*Config, error) {
 		Int("port", config.Server.Port).
 		Dur("shutdown_timeout", config.Shutdown.Timeout).
 		Bool("logging_json", config.Logging.JSON).
+		Bool("telemetry_enabled", config.Telemetry.Enabled).
+		Str("telemetry_service", config.Telemetry.ServiceName).
 		Msg("Configuration loaded")

 	return &config, nil
@@ -86,3 +129,33 @@ func LoadConfig() (*Config, error) {
 func (c *Config) GetServerAddress() string {
 	return fmt.Sprintf("%s:%d", c.Server.Host, c.Server.Port)
 }
+
+// GetTelemetryEnabled returns whether telemetry is enabled
+func (c *Config) GetTelemetryEnabled() bool {
+	return c.Telemetry.Enabled
+}
+
+// GetOTLPEndpoint returns the OTLP endpoint for telemetry
+func (c *Config) GetOTLPEndpoint() string {
+	return c.Telemetry.OTLPEndpoint
+}
+
+// GetServiceName returns the service name for telemetry
+func (c *Config) GetServiceName() string {
+	return c.Telemetry.ServiceName
+}
+
+// GetTelemetryInsecure returns whether to use insecure connection
+func (c *Config) GetTelemetryInsecure() bool {
+	return c.Telemetry.Insecure
+}
+
+// GetSamplerType returns the sampler type
+func (c *Config) GetSamplerType() string {
+	return c.Telemetry.Sampler.Type
+}
+
+// GetSamplerRatio returns the sampler ratio
+func (c *Config) GetSamplerRatio() float64 {
+	return c.Telemetry.Sampler.Ratio
+}
--- a/pkg/server/server.go
+++ b/pkg/server/server.go
@@ -6,6 +6,7 @@ import (

 	"DanceLessonsCoach/pkg/config"
 	"DanceLessonsCoach/pkg/greet"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"

 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
@@ -15,12 +16,14 @@ import (
 type Server struct {
 	router   *chi.Mux
 	readyCtx context.Context
+	withOTEL bool
 }

 func NewServer(cfg *config.Config, readyCtx context.Context) *Server {
 	s := &Server{
 		router:   chi.NewRouter(),
 		readyCtx: readyCtx,
+		withOTEL: cfg.GetTelemetryEnabled(),
 	}
 	s.setupRoutes()
 	return s
@@ -41,7 +44,7 @@ func (s *Server) setupRoutes() {

 	// API routes
 	s.router.Route("/api/v1", func(r chi.Router) {
-		r.Use(s.apiMiddlewares()...)
+		r.Use(s.getAllMiddlewares()...)
 		s.registerApiV1Routes(r)
 	})
 }
@@ -54,11 +57,20 @@ func (s *Server) registerApiV1Routes(r chi.Router) {
 	})
 }

-func (s *Server) apiMiddlewares() []func(http.Handler) http.Handler {
-	return []func(http.Handler) http.Handler{
+// getAllMiddlewares returns all middleware including OpenTelemetry if enabled
+func (s *Server) getAllMiddlewares() []func(http.Handler) http.Handler {
+	middlewares := []func(http.Handler) http.Handler{
 		middleware.StripSlashes,
 		middleware.Recoverer,
 	}
+
+	if s.withOTEL {
+		middlewares = append(middlewares, func(next http.Handler) http.Handler {
+			return otelhttp.NewHandler(next, "")
+		})
+	}
+
+	return middlewares
 }

 func (s *Server) handleHealth(w http.ResponseWriter, r *http.Request) {
--- a/pkg/telemetry/telemetry.go
+++ b/pkg/telemetry/telemetry.go
@@ -0,0 +1,100 @@
+// Package telemetry provides OpenTelemetry instrumentation for the DanceLessonsCoach application
+package telemetry
+
+import (
+	"context"
+	"log"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// Setup initializes OpenTelemetry tracing with the given configuration
+type Setup struct {
+	ServiceName  string
+	OTLPEndpoint string
+	Insecure     bool
+	SamplerType  string
+	SamplerRatio float64
+}
+
+// InitializeTracing sets up OpenTelemetry tracing provider
+func (s *Setup) InitializeTracing(ctx context.Context) (*sdktrace.TracerProvider, error) {
+	// Create OTLP gRPC exporter
+	exporter, err := otlptracegrpc.New(ctx,
+		otlptracegrpc.WithEndpoint(s.OTLPEndpoint),
+		otlptracegrpc.WithInsecure(),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	// Create resource with service name
+	res, err := resource.New(ctx,
+		resource.WithAttributes(
+			semconv.ServiceName(s.ServiceName),
+		),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	// Create sampler based on configuration
+	sampler := s.getSampler()
+
+	// Create trace provider
+	tp := sdktrace.NewTracerProvider(
+		sdktrace.WithBatcher(exporter),
+		sdktrace.WithResource(res),
+		sdktrace.WithSampler(sampler),
+	)
+
+	// Set global tracer provider and propagator
+	otel.SetTracerProvider(tp)
+	otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(
+		propagation.TraceContext{},
+		propagation.Baggage{},
+	))
+
+	return tp, nil
+}
+
+// Shutdown performs cleanup of the tracer provider
+func Shutdown(ctx context.Context, tp *sdktrace.TracerProvider) error {
+	if tp == nil {
+		return nil
+	}
+	return tp.Shutdown(ctx)
+}
+
+// getSampler returns the appropriate sampler based on configuration
+func (s *Setup) getSampler() sdktrace.Sampler {
+	switch s.SamplerType {
+	case "always_on":
+		return sdktrace.AlwaysSample()
+	case "always_off":
+		return sdktrace.NeverSample()
+	case "traceidratio":
+		return sdktrace.TraceIDRatioBased(s.SamplerRatio)
+	case "parentbased_always_on":
+		return sdktrace.ParentBased(sdktrace.AlwaysSample())
+	case "parentbased_always_off":
+		return sdktrace.ParentBased(sdktrace.NeverSample())
+	case "parentbased_traceidratio":
+		return sdktrace.ParentBased(sdktrace.TraceIDRatioBased(s.SamplerRatio))
+	default:
+		log.Printf("Unknown sampler type: %s, defaulting to always_on", s.SamplerType)
+		return sdktrace.AlwaysSample()
+	}
+}
+
+// GetTracer returns a named tracer from the global provider
+// Returns a no-op tracer if OpenTelemetry is not initialized
+func GetTracer(name string) trace.Tracer {
+	return otel.Tracer(name)
+}
--- a/scripts/test-opentelemetry.sh
+++ b/scripts/test-opentelemetry.sh
@@ -0,0 +1,92 @@
+#!/bin/bash
+
+# DanceLessonsCoach OpenTelemetry Test Script
+# This script tests OpenTelemetry integration with Jaeger
+
+set -e
+
+echo -e "\033[1;34m=== DanceLessonsCoach OpenTelemetry Test ===\033[0m"
+echo ""
+
+# Configuration
+PROJECT_DIR="/Users/gabrielradureau/Work/Vibe/DanceLessonsCoach"
+SERVER_CMD="./scripts/start-server.sh"
+LOG_FILE="server.log"
+PID_FILE="server.pid"
+
+cd "$PROJECT_DIR"
+
+# Clean up any existing server
+echo "Cleaning up any existing server..."
+if [ -f "$PID_FILE" ]; then
+    echo "Found existing PID file, stopping previous server..."
+    $SERVER_CMD stop > /dev/null 2>&1 || true
+    rm -f "$PID_FILE" "$LOG_FILE"
+fi
+
+# Kill any processes on port 8080
+pkill -9 -f "go run" > /dev/null 2>&1 || true
+lsof -ti :8080 | xargs -I {} kill -9 {} > /dev/null 2>&1 || true
+lsof -ti :4317 | xargs -I {} kill -9 {} > /dev/null 2>&1 || true
+sleep 1
+
+echo "Starting Jaeger in Docker..."
+# Start Jaeger container if not running
+if ! docker ps | grep -q "jaegertracing/all-in-one"; then
+    docker run -d --name jaeger \
+        -e COLLECTOR_OTLP_ENABLED=true \
+        -p 16686:16686 \
+        -p 4317:4317 \
+        -p 4318:4318 \
+        jaegertracing/all-in-one:latest
+    echo "Jaeger container started"
+    sleep 5
+else
+    echo "Jaeger container already running"
+fi
+
+echo "Starting server with OpenTelemetry enabled..."
+DLC_TELEMETRY_ENABLED=true DLC_TELEMETRY_OTLP_ENDPOINT="localhost:4317" DLC_TELEMETRY_INSECURE=true \
+    DLC_TELEMETRY_SERVICE_NAME="DanceLessonsCoach" $SERVER_CMD start
+sleep 3
+
+echo "Testing API endpoints..."
+
+# Test health endpoint
+echo "Testing /api/health:"
+HEALTH_RESPONSE=$(curl -s http://localhost:8080/api/health)
+echo "Response: $HEALTH_RESPONSE"
+
+# Test greet endpoint
+echo "Testing /api/v1/greet/:"
+GREET_RESPONSE=$(curl -s http://localhost:8080/api/v1/greet/)
+echo "Response: $GREET_RESPONSE"
+
+# Test greet with name
+echo "Testing /api/v1/greet/TestUser:"
+GREET_NAME_RESPONSE=$(curl -s http://localhost:8080/api/v1/greet/TestUser)
+echo "Response: $GREET_NAME_RESPONSE"
+
+echo ""
+echo "Stopping server..."
+$SERVER_CMD stop
+sleep 2
+
+echo ""
+echo -e "\033[0;32m✅ OpenTelemetry Test Complete!\033[0m"
+echo ""
+echo "To view traces in Jaeger:"
+echo "1. Open http://localhost:16686 in your browser"
+echo "2. Select 'DanceLessonsCoach' service"
+echo "3. Click 'Find Traces' button"
+echo ""
+echo "You should see traces for:"
+echo "- /api/health requests"
+echo "- /api/v1/greet/ requests"
+echo "- /api/v1/greet/TestUser requests"
+echo ""
+
+# Clean up
+rm -f "$PID_FILE" "$LOG_FILE"
+
+exit 0
--- a/BIN
+++ b/BIN