82 lines
2.7 KiB
Go
82 lines
2.7 KiB
Go
|
// Copyright 2018 clair authors
|
||
|
|
//
|
||
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
// you may not use this file except in compliance with the License.
|
||
|
|
// You may obtain a copy of the License at
|
||
|
|
//
|
||
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
//
|
||
|
|
// Unless required by applicable law or agreed to in writing, software
|
||
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
// See the License for the specific language governing permissions and
|
||
|
|
// limitations under the License.
|
||
|
|
|
||
|
|
package grpcutil
|
||
|
|
|
||
|
|
import (
|
||
|
|
"crypto/tls"
|
||
|
|
"net/http"
|
||
|
|
"strings"
|
||
|
|
|
||
|
|
"github.com/grpc-ecosystem/grpc-gateway/runtime"
|
||
|
|
"golang.org/x/net/context"
|
||
|
|
"google.golang.org/grpc"
|
||
|
|
"google.golang.org/grpc/credentials"
|
||
|
|
)
|
||
|
|
|
||
|
|
// RegisterServiceHandlerFunc is a function that registers ServiceHandlers with
|
||
|
|
// a ServeMux.
|
||
|
|
type RegisterServiceHandlerFunc func(context.Context, *runtime.ServeMux, *grpc.ClientConn) error
|
||
|
|
|
||
|
|
// NewGateway creates a new http.Handler and grpc.ClientConn with the provided
|
||
|
|
// gRPC Services registered.
|
||
|
|
func NewGateway(addr string, tlsConfig *tls.Config, funcs []RegisterServiceHandlerFunc) (http.Handler, *grpc.ClientConn, error) {
|
||
|
|
// Configure the right DialOptions the for TLS configuration.
|
||
|
|
var dialOpts []grpc.DialOption
|
||
|
|
if tlsConfig != nil {
|
||
|
|
var gwTLSConfig *tls.Config
|
||
|
|
gwTLSConfig = tlsConfig.Clone()
|
||
|
|
gwTLSConfig.InsecureSkipVerify = true // Trust the local server.
|
||
|
|
dialOpts = append(dialOpts, grpc.WithTransportCredentials(credentials.NewTLS(gwTLSConfig)))
|
||
|
|
} else {
|
||
|
|
dialOpts = append(dialOpts, grpc.WithInsecure())
|
||
|
|
}
|
||
|
|
|
||
|
|
conn, err := grpc.DialContext(context.TODO(), addr, dialOpts...)
|
||
|
|
if err != nil {
|
||
|
|
return nil, nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
// Register services.
|
||
|
|
srvmux := runtime.NewServeMux()
|
||
|
|
for _, fn := range funcs {
|
||
|
|
err = fn(context.TODO(), srvmux, conn)
|
||
|
|
if err != nil {
|
||
|
|
return nil, nil, err
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return srvmux, conn, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// IsGRPCRequest returns true if the provided request came from a gRPC client.
|
||
|
|
//
|
||
|
|
// Its logic is a partial recreation of gRPC's internal checks, see:
|
||
|
|
// https://github.com/grpc/grpc-go/blob/01de3de/transport/handler_server.go#L61:L69
|
||
|
|
func IsGRPCRequest(r *http.Request) bool {
|
||
|
|
return r.ProtoMajor == 2 && strings.Contains(r.Header.Get("Content-Type"), "application/grpc")
|
||
|
|
}
|
||
|
|
|
||
|
|
// HandlerFunc returns an http.Handler that delegates to grpc.Server on
|
||
|
|
// incoming gRPC connections otherwise serves with the provided handler.
|
||
|
|
func HandlerFunc(grpcServer *grpc.Server, otherwise http.Handler) http.Handler {
|
||
|
|
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
|
||
|
|
if IsGRPCRequest(r) {
|
||
|
|
grpcServer.ServeHTTP(w, r)
|
||
|
|
} else {
|
||
|
|
otherwise.ServeHTTP(w, r)
|
||
|
|
}
|
||
|
|
})
|
||
|
|
}
|