feat(http): Add HTTP middleware to the observability modules

examples/cmd/http-server/main.go

@@ -0,0 +1,95 @@
+package main
+
+import (
+	"log"
+	"os"
+
+	sconfig "github.com/exoscale/stelling/config"
+	"github.com/exoscale/stelling/examples/config"
+	"github.com/exoscale/stelling/examples/server"
+	"github.com/exoscale/stelling/fxhttp"
+	"github.com/exoscale/stelling/fxlogging"
+	"github.com/exoscale/stelling/fxmetrics"
+	"github.com/exoscale/stelling/fxpprof"
+	"github.com/exoscale/stelling/fxsentry"
+	"github.com/exoscale/stelling/fxtracing"
+	"go.uber.org/fx"
+)
+
+func main() {
+	// Immediately log a line to show that we've started
+	// This can help debug whether something is failing to start us or whether we are
+	// stuck in system startup
+	log.Println("starting server")
+
+	// Create the object in which we'll try to load our configuration
+	conf := &config.Config{}
+
+	// Load the configuration:
+	// It will use a config file, environment variables and cli flags
+	if err := sconfig.Load(conf, os.Args); err != nil {
+		// Config failed to load or failed validation
+		// Error out and let the user know why
+		log.Fatal(err)
+	}
+
+	app := fx.New(createSystem(conf))
+
+	// Start the application:
+	// This will run until we receive a signal to shut down
+	// It handles its own errors
+	app.Run()
+}
+
+// createSystem turns the configuration into a system that can be run
+// We extract this in a function, because it allows us to write tests
+// that assert that it contains all necessary dependencies
+func createSystem(conf *config.Config) fx.Option {
+	opts := fx.Options(
+		// Insert the configuration as is: this allows other components to reference it
+		fx.Supply(conf),
+
+		// Add the modules from stelling:
+		// These will insert constructors for the various components,
+		// as well as register lifecycle hooks if necessary
+
+		// fxlogging adds a *zap.Logger into the system
+		fxlogging.NewModule(conf),
+
+		// fxpprof starts a pprof server on its own http-server
+		// pprof instruments the go runtime directly, you do not have to write any more code
+		fxpprof.NewModule(conf),
+		// fxmetrics adds a *prometheus.Registry to the system that you can register
+		// custom metrics on
+		// It also starts its own http-server to expose the prometheus endpoint
+		// In case the system uses grpc, it will wire up middleware and expose grpc
+		// metrics, such as request counts
+		fxmetrics.NewModule(conf),
+		// fxtracing adds a trace.TraceProvider to the system: this can be used to create
+		// top-level spans
+		// In case the system uses grpc, middleware will be wired up that traces each request
+		// As always in go: the current span can be retrieved from the passed in context
+		fxtracing.NewModule(conf),
+		// fxsentry adds a *sentry.Client to the system
+		// It will also configure the zap DPanic level to emit a sentry
+		fxsentry.NewModule(conf),
+		// fxhttp.NewModule provides a http.Server to the system
+		// It is up to you to provide an http.Handler and optionally an RpcMethodMapper
+		// Alternatively, you can provide the fxhttp.RPCMethodMapper type directly
+		// if it needs additional system dependencies
+		fxhttp.NewModule(&conf.HttpServer, fxhttp.WithRPCMethodMapper(server.RpcMapper)),
+
+		// Insert our application components
+		fx.Provide(
+			server.NewHttpMux,
+		),
+
+		// Invoke functions are run in the order in which they are specified
+		fx.Invoke(
+			// Invoke the http server
+			fxhttp.StartHttpServer,
+		),
+	)
+
+	return opts
+}

examples/config/config.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/exoscale/stelling/config"
 	"github.com/exoscale/stelling/fxgrpc"
+	"github.com/exoscale/stelling/fxhttp"
 	"github.com/exoscale/stelling/fxlogging"
 	"github.com/exoscale/stelling/fxmetrics"
 	"github.com/exoscale/stelling/fxpprof"
@@ -19,6 +20,7 @@ type Config struct {
 	fxmetrics.Metrics
 	fxtracing.Tracing
 	fxsentry.Sentry
+	HttpServer fxhttp.Server
 
 	FeatureFlag    bool
 	Mode           string        `default:"high" validate:"oneof=low medium high"`

examples/go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/exoscale/multiconfig v0.0.0-20260223134601-625dc5777c41 // indirect
 	github.com/fatih/camelcase v1.0.0 // indirect
 	github.com/fatih/structs v1.1.0 // indirect
+	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/gabriel-vasile/mimetype v1.4.13 // indirect
 	github.com/getsentry/sentry-go v0.43.0 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
@@ -46,15 +47,16 @@ require (
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
 	go.opentelemetry.io/contrib/bridges/prometheus v0.66.0 // indirect
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.66.0 // indirect
-	go.opentelemetry.io/otel v1.41.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.67.0 // indirect
+	go.opentelemetry.io/otel v1.42.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.41.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.41.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.41.0 // indirect
 	go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.41.0 // indirect
-	go.opentelemetry.io/otel/metric v1.41.0 // indirect
-	go.opentelemetry.io/otel/sdk v1.41.0 // indirect
-	go.opentelemetry.io/otel/sdk/metric v1.41.0 // indirect
-	go.opentelemetry.io/otel/trace v1.41.0 // indirect
+	go.opentelemetry.io/otel/metric v1.42.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.42.0 // indirect
+	go.opentelemetry.io/otel/sdk/metric v1.42.0 // indirect
+	go.opentelemetry.io/otel/trace v1.42.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.9.0 // indirect
 	go.uber.org/dig v1.19.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect

examples/go.sum

@@ -18,6 +18,8 @@ github.com/fatih/camelcase v1.0.0 h1:hxNvNX/xYBp0ovncs8WyWZrOrpBNub/JfaMvbURyft8
 github.com/fatih/camelcase v1.0.0/go.mod h1:yN2Sb0lFhZJUdVvtELVWefmrXpuZESvPmqwoZc+/fpc=
 github.com/fatih/structs v1.1.0 h1:Q7juDM0QtcnhCpeyLGQKyg4TOIghuNXrkL32pHAUMxo=
 github.com/fatih/structs v1.1.0/go.mod h1:9NiDSp5zOcgEDl+j00MP/WkGVPOlPRLejGD8Ga6PJ7M=
+github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
+github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/gabriel-vasile/mimetype v1.4.13 h1:46nXokslUBsAJE/wMsp5gtO500a4F3Nkz9Ufpk2AcUM=
 github.com/gabriel-vasile/mimetype v1.4.13/go.mod h1:d+9Oxyo1wTzWdyVUPMmXFvp4F9tea18J8ufA774AB3s=
 github.com/getsentry/sentry-go v0.43.0 h1:XbXLpFicpo8HmBDaInk7dum18G9KSLcjZiyUKS+hLW4=
@@ -90,8 +92,10 @@ go.opentelemetry.io/contrib/bridges/prometheus v0.66.0 h1:nQlJkSnoq/O+z7Az1CjwM+
 go.opentelemetry.io/contrib/bridges/prometheus v0.66.0/go.mod h1:U87nfzwzcfDvqTeRnI+dBHMAmHGQf9AWqvTC2dAv8as=
 go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.66.0 h1:w/o339tDd6Qtu3+ytwt+/jon2yjAs3Ot8Xq8pelfhSo=
 go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.66.0/go.mod h1:pdhNtM9C4H5fRdrnwO7NjxzQWhKSSxCHk/KluVqDVC0=
-go.opentelemetry.io/otel v1.41.0 h1:YlEwVsGAlCvczDILpUXpIpPSL/VPugt7zHThEMLce1c=
-go.opentelemetry.io/otel v1.41.0/go.mod h1:Yt4UwgEKeT05QbLwbyHXEwhnjxNO6D8L5PQP51/46dE=
+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 v1.42.0 h1:lSQGzTgVR3+sgJDAU/7/ZMjN9Z+vUip7leaqBKy4sho=
+go.opentelemetry.io/otel v1.42.0/go.mod h1:lJNsdRMxCUIWuMlVJWzecSMuNjE7dOYyWlqOXWkdqCc=
 go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.41.0 h1:VO3BL6OZXRQ1yQc8W6EVfJzINeJ35BkiHx4MYfoQf44=
 go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.41.0/go.mod h1:qRDnJ2nv3CQXMK2HUd9K9VtvedsPAce3S+/4LZHjX/s=
 go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.41.0 h1:ao6Oe+wSebTlQ1OEht7jlYTzQKE+pnx/iNywFvTbuuI=
@@ -100,14 +104,14 @@ go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.41.0 h1:mq/Qc
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.41.0/go.mod h1:yk5LXEYhsL2htyDNJbEq7fWzNEigeEdV5xBF/Y+kAv0=
 go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.41.0 h1:61oRQmYGMW7pXmFjPg1Muy84ndqMxQ6SH2L8fBG8fSY=
 go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.41.0/go.mod h1:c0z2ubK4RQL+kSDuuFu9WnuXimObon3IiKjJf4NACvU=
-go.opentelemetry.io/otel/metric v1.41.0 h1:rFnDcs4gRzBcsO9tS8LCpgR0dxg4aaxWlJxCno7JlTQ=
-go.opentelemetry.io/otel/metric v1.41.0/go.mod h1:xPvCwd9pU0VN8tPZYzDZV/BMj9CM9vs00GuBjeKhJps=
-go.opentelemetry.io/otel/sdk v1.41.0 h1:YPIEXKmiAwkGl3Gu1huk1aYWwtpRLeskpV+wPisxBp8=
-go.opentelemetry.io/otel/sdk v1.41.0/go.mod h1:ahFdU0G5y8IxglBf0QBJXgSe7agzjE4GiTJ6HT9ud90=
-go.opentelemetry.io/otel/sdk/metric v1.41.0 h1:siZQIYBAUd1rlIWQT2uCxWJxcCO7q3TriaMlf08rXw8=
-go.opentelemetry.io/otel/sdk/metric v1.41.0/go.mod h1:HNBuSvT7ROaGtGI50ArdRLUnvRTRGniSUZbxiWxSO8Y=
-go.opentelemetry.io/otel/trace v1.41.0 h1:Vbk2co6bhj8L59ZJ6/xFTskY+tGAbOnCtQGVVa9TIN0=
-go.opentelemetry.io/otel/trace v1.41.0/go.mod h1:U1NU4ULCoxeDKc09yCWdWe+3QoyweJcISEVa1RBzOis=
+go.opentelemetry.io/otel/metric v1.42.0 h1:2jXG+3oZLNXEPfNmnpxKDeZsFI5o4J+nz6xUlaFdF/4=
+go.opentelemetry.io/otel/metric v1.42.0/go.mod h1:RlUN/7vTU7Ao/diDkEpQpnz3/92J9ko05BIwxYa2SSI=
+go.opentelemetry.io/otel/sdk v1.42.0 h1:LyC8+jqk6UJwdrI/8VydAq/hvkFKNHZVIWuslJXYsDo=
+go.opentelemetry.io/otel/sdk v1.42.0/go.mod h1:rGHCAxd9DAph0joO4W6OPwxjNTYWghRWmkHuGbayMts=
+go.opentelemetry.io/otel/sdk/metric v1.42.0 h1:D/1QR46Clz6ajyZ3G8SgNlTJKBdGp84q9RKCAZ3YGuA=
+go.opentelemetry.io/otel/sdk/metric v1.42.0/go.mod h1:Ua6AAlDKdZ7tdvaQKfSmnFTdHx37+J4ba8MwVCYM5hc=
+go.opentelemetry.io/otel/trace v1.42.0 h1:OUCgIPt+mzOnaUTpOQcBiM/PLQ/Op7oq6g4LenLmOYY=
+go.opentelemetry.io/otel/trace v1.42.0/go.mod h1:f3K9S+IFqnumBkKhRJMeaZeNk9epyhnCmQh/EysQCdc=
 go.opentelemetry.io/proto/otlp v1.9.0 h1:l706jCMITVouPOqEnii2fIAuO3IVGBRPV5ICjceRb/A=
 go.opentelemetry.io/proto/otlp v1.9.0/go.mod h1:xE+Cx5E/eEHw+ISFkwPLwCZefwVjY+pqKg1qcK03+/4=
 go.uber.org/dig v1.19.0 h1:BACLhebsYdpQ7IROQ1AGPjrXcP5dF80U3gKoFzbaq/4=

examples/server/server.go

@@ -1,6 +1,10 @@
 package server
 
-import pb "google.golang.org/grpc/examples/route_guide/routeguide"
+import (
+	"net/http"
+
+	pb "google.golang.org/grpc/examples/route_guide/routeguide"
+)
 
 type RouteGuideServer struct {
 	pb.UnimplementedRouteGuideServer
@@ -12,3 +16,16 @@ type RouteGuideServer struct {
 func NewServer() pb.RouteGuideServer {
 	return &RouteGuideServer{}
 }
+
+// NewHttpMux provides a handler for an http.Server
+func NewHttpMux() http.Handler {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	})
+	return mux
+}
+
+func RpcMapper(req *http.Request) string {
+	return "get-health"
+}