chore: initial commit

internal/pkg/serve/gateway.go

@@ -0,0 +1,114 @@
+// Copyright (C) 2024 Declan Teevan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package serve
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
+	"github.com/rs/zerolog/log"
+	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/metadata"
+
+	"github.com/hexolan/stocklet/internal/pkg/config"
+	"github.com/hexolan/stocklet/internal/pkg/gwauth"
+)
+
+func withGatewayErrorHandler() runtime.ServeMuxOption {
+	return runtime.WithErrorHandler(
+		func(ctx context.Context, mux *runtime.ServeMux, marshaler runtime.Marshaler, w http.ResponseWriter, r *http.Request, err error) {
+			runtime.DefaultHTTPErrorHandler(ctx, mux, marshaler, w, r, err)
+			log.Error().Err(err).Stack().Str("path", r.URL.Path).Str("reqURI", r.RequestURI).Str("remoteAddr", r.RemoteAddr).Msg("")
+		},
+	)
+}
+
+func withGatewayMetadataOpt() runtime.ServeMuxOption {
+	return runtime.WithMetadata(
+		func(ctx context.Context, req *http.Request) metadata.MD {
+			return metadata.MD{"from-gateway": {"true"}}
+		},
+	)
+}
+
+func withGatewayHeaderOpt() runtime.ServeMuxOption {
+	return runtime.WithIncomingHeaderMatcher(
+		func(key string) (string, bool) {
+			switch key {
+			case gwauth.JWTPayloadHeader:
+				// Envoy will validate JWT tokens and provide a payload header
+				// containing a base64 string of the token claims.
+				return "jwt-payload", true
+			default:
+				return key, false
+			}
+		},
+	)
+}
+
+func withGatewayLogger(h http.Handler) http.Handler {
+	return http.HandlerFunc(
+		func(w http.ResponseWriter, r *http.Request) {
+			h.ServeHTTP(w, r)
+			log.Info().Str("path", r.URL.Path).Str("reqURI", r.RequestURI).Str("remoteAddr", r.RemoteAddr).Msg("")
+		},
+	)
+}
+
+func NewGatewayServeBase(cfg *config.SharedConfig) (*runtime.ServeMux, []grpc.DialOption) {
+	// Create the base runtime ServeMux
+	mux := runtime.NewServeMux(
+		withGatewayErrorHandler(),
+		withGatewayMetadataOpt(),
+		withGatewayHeaderOpt(),
+	)
+
+	// Attach open telemetry instrumentation through the gRPC client options
+	clientOpts := []grpc.DialOption{
+		grpc.WithStatsHandler(
+			otelgrpc.NewClientHandler(),
+		),
+
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
+	}
+
+	return mux, clientOpts
+}
+
+func Gateway(mux *runtime.ServeMux) error {
+	// Create OTEL instrumentation handler
+	handler := otelhttp.NewHandler(
+		mux,
+		"grpc-gateway",
+		otelhttp.WithSpanNameFormatter(
+			func(operation string, r *http.Request) string {
+				return operation + ": " + r.RequestURI
+			},
+		),
+	)
+
+	// Create gateway HTTP server
+	svr := &http.Server{
+		Addr:    GetAddrToGateway("0.0.0.0"),
+		Handler: withGatewayLogger(handler),
+	}
+
+	return svr.ListenAndServe()
+}

internal/pkg/serve/grpc.go

@@ -0,0 +1,62 @@
+// Copyright (C) 2024 Declan Teevan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package serve
+
+import (
+	"net"
+
+	"github.com/rs/zerolog/log"
+	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/health"
+	"google.golang.org/grpc/health/grpc_health_v1"
+	"google.golang.org/grpc/reflection"
+
+	"github.com/hexolan/stocklet/internal/pkg/config"
+)
+
+func NewGrpcServeBase(cfg *config.SharedConfig) *grpc.Server {
+	// Attach OTEL metrics middleware
+	svr := grpc.NewServer(
+		grpc.StatsHandler(
+			otelgrpc.NewServerHandler(),
+		),
+	)
+
+	// Attach the health service
+	svc := health.NewServer()
+	grpc_health_v1.RegisterHealthServer(svr, svc)
+
+	// Enable reflection in dev mode
+	// Eases usage of tools like grpcurl and grpcui
+	if cfg.DevMode {
+		reflection.Register(svr)
+	}
+
+	return svr
+}
+
+func Grpc(svr *grpc.Server) {
+	lis, err := net.Listen("tcp", GetAddrToGrpc("0.0.0.0"))
+	if err != nil {
+		log.Panic().Err(err).Str("port", grpcPort).Msg("failed to listen on gRPC port")
+	}
+
+	err = svr.Serve(lis)
+	if err != nil {
+		log.Panic().Err(err).Msg("failed to serve gRPC server")
+	}
+}

internal/pkg/serve/serve.go

@@ -0,0 +1,32 @@
+// Copyright (C) 2024 Declan Teevan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package serve
+
+// Port Definitions
+const (
+	grpcPort    string = "9090"
+	gatewayPort string = "90"
+)
+
+// Get an address to a gRPC server using the standard port
+func GetAddrToGrpc(host string) string {
+	return host + ":" + grpcPort
+}
+
+// Get an address to a gRPC-gateway interface using the standard port
+func GetAddrToGateway(host string) string {
+	return host + ":" + gatewayPort
+}