mirror of https://github.com/grpc/grpc-go.git
61 lines
1.8 KiB
Go
61 lines
1.8 KiB
Go
/*
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*
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* Copyright 2018 gRPC 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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*
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*/
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// Package service manages connections between the VM application and the ALTS
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// handshaker service.
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package service
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import (
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"flag"
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"sync"
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grpc "google.golang.org/grpc"
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)
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var (
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// hsServiceAddr specifies the default ALTS handshaker service address in
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// the hypervisor.
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hsServiceAddr = flag.String("handshaker_service_address", "metadata.google.internal:8080", "ALTS handshaker gRPC service address")
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// hsConn represents a connection to hypervisor handshaker service.
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hsConn *grpc.ClientConn
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mu sync.Mutex
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// hsDialer will be reassigned in tests.
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hsDialer = grpc.Dial
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)
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type dialer func(target string, opts ...grpc.DialOption) (*grpc.ClientConn, error)
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// Dial dials the handshake service in the hypervisor. If a connection has
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// already been established, this function returns it. Otherwise, a new
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// connection is created,
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func Dial() (*grpc.ClientConn, error) {
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mu.Lock()
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defer mu.Unlock()
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if hsConn == nil {
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// Create a new connection to the handshaker service. Note that
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// this connection stays open until the application is closed.
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var err error
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hsConn, err = hsDialer(*hsServiceAddr, grpc.WithInsecure())
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if err != nil {
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return nil, err
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}
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}
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return hsConn, nil
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}
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