Go

1. Prerequisites

Go 1.17+ Check with:

go version

• Middleware Host Agent on the same machine (host-based only). If your app is in containers/Kubernetes, set MW_AGENT_SERVICE so your app can reach the Host Agent.
  • Docker: MW_AGENT_SERVICE should point to the Docker bridge gateway (default 172.17.0.1).
  • Kubernetes: MW_AGENT_SERVICE=mw-service.mw-agent-ns.svc.cluster.local.

2. Install the Go APM package

go get github.com/middleware-labs/golang-apm@latest

Add imports at your entry point (first import block):
import (
  track "github.com/middleware-labs/golang-apm/tracker"
)

The accessToken is your MW account key (see Installation page in the app).

3. Instrumentation

Pick Host (with the Host Agent) or Serverless (send directly to Middleware). In both cases, you initialise once at startup with track.Track(...).

// main.go (in func main)
config, err := track.Track(
  track.WithConfigTag("service", "YOUR_SERVICE_NAME"),
  track.WithConfigTag("accessToken", "<MW_API_KEY>"), // optional in Host mode
)
if err != nil { panic(err) }
defer func() { _ = config.Tp.Shutdown(context.Background()) }()

config, err := track.Track(
  track.WithConfigTag("service", "YOUR_SERVICE_NAME"),
  track.WithConfigTag("accessToken", "<MW_API_KEY>"),
  track.WithConfigTag("target", "https://<MW_UID>.middleware.io:443"),
)
if err != nil { panic(err) }
defer func() { _ = config.Tp.Shutdown(context.Background()) }()

4. Framework quick-starts

go get github.com/middleware-labs/golang-apm-http

import (
  "net/http"
  track "github.com/middleware-labs/golang-apm/tracker"
  mwhttp "github.com/middleware-labs/golang-apm-http/http"
)

func main() {
  go track.Track(
    track.WithConfigTag(track.Service, "your service"),
    track.WithConfigTag(track.Token,   "<MW_API_KEY>"),
  )
  http.Handle("/hello", mwhttp.MiddlewareHandler(http.HandlerFunc(hello), "hello"))
}

go get github.com/middleware-labs/golang-apm-gin@latest

import (
  "github.com/gin-gonic/gin"
  track "github.com/middleware-labs/golang-apm/tracker"
  mwgin "github.com/middleware-labs/golang-apm-gin/gin"
)

func main() {
  r := gin.Default()
  config, _ := track.Track(
    track.WithConfigTag("service","<apm-service>"),
    track.WithConfigTag("accessToken","<MW_API_KEY>"),
  )
  r.Use(mwgin.Middleware(config))
}

go get github.com/middleware-labs/golang-apm-mux@latest

import (
  "github.com/gorilla/mux"
  track "github.com/middleware-labs/golang-apm/tracker"
  mwmux "github.com/middleware-labs/golang-apm-mux/mux"
)

func main() {
  r := mux.NewRouter()
  config, _ := track.Track(
    track.WithConfigTag("service","<apm-service>"),
    track.WithConfigTag("accessToken","<MW_API_KEY>"),
  )
  r.Use(mwmux.Middleware(config))
}

go get github.com/middleware-labs/agent-apm-go-chi-legacy@latest

import (
  "github.com/go-chi/chi"
  track "github.com/middleware-labs/golang-apm/tracker"
  mwchi "github.com/middleware-labs/agent-apm-go-chi-legacy"
)

func main() {
  r := chi.NewRouter()
  config, _ := track.Track(
    track.WithConfigTag("service","<apm-service>"),
    track.WithConfigTag("accessToken","<MW_API_KEY>"),
  )
  r.Use(mwchi.Middleware("<my-server>", mwchi.WithChiRoutes(r)))
}

go get github.com/middleware-labs/agent-apm-go-chi@latest

import (
  "github.com/go-chi/chi/v5"
  track "github.com/middleware-labs/golang-apm/tracker"
  mwchi "github.com/middleware-labs/agent-apm-go-chi"
)

go get github.com/middleware-labs/golang-apm-beego@latest

import (
  track "github.com/middleware-labs/golang-apm/tracker"
  mwbeego "github.com/middleware-labs/golang-apm-beego/beego"
)

go get github.com/middleware-labs/golang-apm-sql@latest

import (
  track "github.com/middleware-labs/golang-apm/tracker"
  mwsql "github.com/middleware-labs/golang-apm-sql/sql"
)
db, err := mwsql.Open("mysql", "user:pass@tcp(127.0.0.1:3306)/dbname")

go get github.com/middleware-labs/golang-apm-mongo@latest

import (
  "go.mongodb.org/mongo-driver/mongo/options"
  track "github.com/middleware-labs/golang-apm/tracker"
  mwmongo "github.com/middleware-labs/golang-apm-mongo/mongo"
)
opts := options.Client()
opts.Monitor = mwmongo.NewMonitor()

go get github.com/middleware-labs/golang-apm-grpc@latest

import (
  "google.golang.org/grpc"
  mwgrpc "github.com/middleware-labs/golang-apm-grpc/grpc"
  track "github.com/middleware-labs/golang-apm/tracker"
)

server := grpc.NewServer(
  grpc.UnaryInterceptor(mwgrpc.UnaryServerInterceptor()),
  grpc.StreamInterceptor(mwgrpc.StreamServerInterceptor()),
)

5. Sending custom data

A. Custom logs (choose your logger)

All adapters below forward structured logs to Middleware with active trace/span context.

• log/slog:
  Your API Keys

  import (
      "log/slog"
      "github.com/middleware-labs/golang-apm/mwotelslog"
      track "github.com/middleware-labs/golang-apm/tracker"
      )
  
      config, _ := track.Track(
      track.WithConfigTag(track.Service, "svc"),
      track.WithConfigTag(track.Token,   "<MW_API_KEY>"),
      )
  
      logger := mwotelslog.NewMWOTelLogger(config,
      mwotelslog.WithDefaultConsoleLog(),
      mwotelslog.WithName("otelslog"),
      )
      slog.SetDefault(logger)

• Zap:
  Your API Keys

  import (
          "go.uber.org/zap"
          "go.uber.org/zap/zapcore"
          mwotelzap "github.com/middleware-labs/golang-apm/mwotelzap"
          track "github.com/middleware-labs/golang-apm/tracker"
      )
  
      config, _ := track.Track(
          track.WithConfigTag(track.Service, "svc"),
          track.WithConfigTag(track.Token,   "<MW_API_KEY>"),
      )
  
      logger := zap.New(zapcore.NewTee(/* consoleCore, fileCore, */ mwotelzap.NewMWOTelCore(config, mwotelzap.WithName("otelzaplog"))))
      zap.ReplaceGlobals(logger)

• zerolog

import (
  "github.com/rs/zerolog/log"
  mwotelzerolog "github.com/middleware-labs/golang-apm/mwotelzerolog"
  track "github.com/middleware-labs/golang-apm/tracker"
)

config, _ := track.Track(
  track.WithConfigTag(track.Service, "svc"),
  track.WithConfigTag(track.Token,   "<MW_API_KEY>"),
)
hook := mwotelzerolog.NewMWOTelHook(config)
logger := log.Hook(hook)

• logrus

import (
  log "github.com/sirupsen/logrus"
  otellog "github.com/middleware-labs/golang-apm/mwotellogrus"
  track "github.com/middleware-labs/golang-apm/tracker"
)

config, _ := track.Track(
  track.WithConfigTag(track.Service, "svc"),
  track.WithConfigTag(track.Token,   "<MW_API_KEY>"),
)
logHook := otellog.NewMWOTelHook(config, otellog.WithLevels(log.AllLevels), otellog.WithName("otellogrus"))
log.AddHook(logHook)
log.SetFormatter(&log.JSONFormatter{})

B. Record errors (stack traces)

err := errors.New("something went wrong")
track.ErrorRecording(ctx, err)

C. Get current span

span := track.SpanFromContext(ctx)

D. Custom spans, events & attributes (quick taste)

config, _ := track.Track(
  track.WithConfigTag("service", "<APM-SERVICE-NAME>"),
  track.WithConfigTag("accessToken", "<MW_API_KEY>"),
)
tp := config.Tp

ctx, span := tp.Tracer("example-tracer").Start(ctx, "example-span")
span.AddEvent("starting work")
track.SetAttribute(ctx, "user.id", "123")
defer span.End()

6. Continuous profiling

Profiling starts automatically once the tracker is configured (Step 2). Use the Continuous Profiling section in the app to explore CPU, memory, goroutines, etc.

7. Telemetry & debug options

• Pause default runtime metrics only

  track.WithConfigTag(track.PauseDefaultMetrics, true)

• Pause metrics / traces / logs / profiling

  track.WithConfigTag(track.PauseMetrics|PauseTraces|PauseLogs|PauseProfiling, true)

  (You can also use the matching MW_APM_COLLECT_* env vars below.)
• Debug to console

  track.WithConfigTag(track.Debug, true)

• Debug to files

  track.WithConfigTag(track.Debug, true) + track.WithConfigTag(track.DebugLogFile, true)

8. Environment variables (quick reference)

9. View your data

After a short delay, you’ll see telemetry in the Middleware app:

• APM: service overview, traces, errors
• Logs: any logs forwarded via adapters above
• Continuous Profiling: CPU/mem/goroutine flamegraphs

See “Viewing Data” for where these live in the UI.10. Troubleshooting

• No data from containers/K8s → verify MW_AGENT_SERVICE (Docker bridge gateway is often 172.17.0.1; use the K8s service DNS shown above).
• High local noise → enable Debug to see what’s emitted (track.Debug, track.DebugLogFile).
• Too much overhead → pause what you don’t need (PauseMetrics/DefaultMetrics/Traces/Logs/Profiling or the env vars).