Files
stocklet/internal/pkg/serve/gateway.go
2024-04-16 22:27:52 +01:00

115 lines
3.4 KiB
Go

// 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()
}