1ec2759550
This change refactors gRPC code used within the v3 API package into generic code that can be used for managing gRPC and gRPC Gateway.
82 lines
2.7 KiB
Go
82 lines
2.7 KiB
Go
// Copyright 2018 clair authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package grpcutil
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import (
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"crypto/tls"
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"net/http"
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"strings"
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"github.com/grpc-ecosystem/grpc-gateway/runtime"
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"golang.org/x/net/context"
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"google.golang.org/grpc"
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"google.golang.org/grpc/credentials"
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)
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// RegisterServiceHandlerFunc is a function that registers ServiceHandlers with
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// a ServeMux.
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type RegisterServiceHandlerFunc func(context.Context, *runtime.ServeMux, *grpc.ClientConn) error
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// NewGateway creates a new http.Handler and grpc.ClientConn with the provided
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// gRPC Services registered.
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func NewGateway(addr string, tlsConfig *tls.Config, funcs []RegisterServiceHandlerFunc) (http.Handler, *grpc.ClientConn, error) {
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// Configure the right DialOptions the for TLS configuration.
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var dialOpts []grpc.DialOption
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if tlsConfig != nil {
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var gwTLSConfig *tls.Config
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gwTLSConfig = tlsConfig.Clone()
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gwTLSConfig.InsecureSkipVerify = true // Trust the local server.
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dialOpts = append(dialOpts, grpc.WithTransportCredentials(credentials.NewTLS(gwTLSConfig)))
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} else {
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dialOpts = append(dialOpts, grpc.WithInsecure())
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}
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conn, err := grpc.DialContext(context.TODO(), addr, dialOpts...)
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if err != nil {
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return nil, nil, err
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}
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// Register services.
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srvmux := runtime.NewServeMux()
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for _, fn := range funcs {
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err = fn(context.TODO(), srvmux, conn)
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if err != nil {
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return nil, nil, err
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}
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}
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return srvmux, conn, nil
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}
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// IsGRPCRequest returns true if the provided request came from a gRPC client.
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//
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// Its logic is a partial recreation of gRPC's internal checks, see:
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// https://github.com/grpc/grpc-go/blob/01de3de/transport/handler_server.go#L61:L69
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func IsGRPCRequest(r *http.Request) bool {
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return r.ProtoMajor == 2 && strings.Contains(r.Header.Get("Content-Type"), "application/grpc")
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}
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// HandlerFunc returns an http.Handler that delegates to grpc.Server on
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// incoming gRPC connections otherwise serves with the provided handler.
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func HandlerFunc(grpcServer *grpc.Server, otherwise http.Handler) http.Handler {
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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if IsGRPCRequest(r) {
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grpcServer.ServeHTTP(w, r)
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} else {
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otherwise.ServeHTTP(w, r)
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}
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})
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}
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