grpc-go/security/advancedtls/examples/credential_reloading_from_f.../client/main.go

112 lines
3.6 KiB
Go

/*
*
* Copyright 2020 gRPC 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.
*
*/
// The client demonstrates how to use the credential reloading feature in
// advancedtls to make a mTLS connection to the server.
package main
import (
"context"
"flag"
"log"
"time"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials/tls/certprovider/pemfile"
pb "google.golang.org/grpc/examples/helloworld/helloworld"
"google.golang.org/grpc/security/advancedtls"
"google.golang.org/grpc/security/advancedtls/testdata"
)
var address = "localhost:50051"
const (
// Default timeout for normal connections.
defaultTimeout = 2 * time.Second
// Intervals that set to monitor the credential updates.
credRefreshingInterval = 500 * time.Millisecond
)
func main() {
tmpKeyFile := flag.String("key", "", "temporary key file path")
tmpCertFile := flag.String("cert", "", "temporary cert file path")
flag.Parse()
if tmpKeyFile == nil || *tmpKeyFile == "" {
log.Fatalf("tmpKeyFile is nil or empty.")
}
if tmpCertFile == nil || *tmpCertFile == "" {
log.Fatalf("tmpCertFile is nil or empty.")
}
// Initialize credential struct using reloading API.
identityOptions := pemfile.Options{
CertFile: *tmpCertFile,
KeyFile: *tmpKeyFile,
RefreshDuration: credRefreshingInterval,
}
identityProvider, err := pemfile.NewProvider(identityOptions)
if err != nil {
log.Fatalf("pemfile.NewProvider(%v) failed: %v", identityOptions, err)
}
rootOptions := pemfile.Options{
RootFile: testdata.Path("client_trust_cert_1.pem"),
RefreshDuration: credRefreshingInterval,
}
rootProvider, err := pemfile.NewProvider(rootOptions)
if err != nil {
log.Fatalf("pemfile.NewProvider(%v) failed: %v", rootOptions, err)
}
options := &advancedtls.Options{
IdentityOptions: advancedtls.IdentityCertificateOptions{
IdentityProvider: identityProvider,
},
AdditionalPeerVerification: func(*advancedtls.HandshakeVerificationInfo) (*advancedtls.PostHandshakeVerificationResults, error) {
return &advancedtls.PostHandshakeVerificationResults{}, nil
},
RootOptions: advancedtls.RootCertificateOptions{
RootProvider: rootProvider,
},
VerificationType: advancedtls.CertVerification,
}
clientTLSCreds, err := advancedtls.NewClientCreds(options)
if err != nil {
log.Fatalf("advancedtls.NewClientCreds(%v) failed: %v", options, err)
}
// Make a connection using the credentials.
conn, err := grpc.NewClient(address, grpc.WithTransportCredentials(clientTLSCreds))
if err != nil {
log.Fatalf("grpc.NewClient to %s failed: %v", address, err)
}
client := pb.NewGreeterClient(conn)
// Send the requests every 0.5s. The credential is expected to be changed in
// the bash script. We don't cancel the context nor call conn.Close() here,
// since the bash script is expected to close the client goroutine.
for {
ctx, cancel := context.WithTimeout(context.Background(), defaultTimeout)
_, err = client.SayHello(ctx, &pb.HelloRequest{Name: "gRPC"}, grpc.WaitForReady(true))
if err != nil {
log.Fatalf("client.SayHello failed: %v", err)
}
cancel()
time.Sleep(500 * time.Millisecond)
}
}