golang ssh replacement ssh ProxyCommand by nc

I'm planning to implement a golang version ssh client to connect to destination server by a bastion.But unfortunately,I failed at the replacement for nc proxy.

At my local ssh config:

Host bastion
HostName xxx.xxx.xxx.xxx
User ec2-user
IdentityFile ~/.ssh/xxx-bastion.pem
Host 10.0.*.*
User ec2-user
IdentityFile ~/.ssh/xxx-dest.pem
ProxyCommand ssh -q bastion "nc -w 3600 %h %p"

my golang implementation is like the following:

<!-- language: go-->

var(
Bastion="xxx.xxx.xxx.xxx:22"
Target="xxx.xxx.xxx.xxx:22"
BastionPem ="/Users/me/.ssh/xxx-bastion.pem"
DestPem ="/Users/me/.ssh/xxx-dest.pem"
Timeout=30*time.Second
)
func BastionConfig() (*ssh.ClientConfig,error){
pemBytes, err := ioutil.ReadFile(BastionPem)
if err != nil {
log.Fatal(err)
}
signer, err := ssh.ParsePrivateKey(pemBytes)
if err != nil {
log.Fatalf("parse key failed:%v", err)
}
config := &ssh.ClientConfig{
User: "ec2-user",
Auth: []ssh.AuthMethod{ssh.PublicKeys(signer)},
Timeout:Timeout,
}
return config,err
}
func DestConfig() (*ssh.ClientConfig,error){
pemBytes, err := ioutil.ReadFile(TargetPem)
if err != nil {
log.Fatal(err)
}
signer, err := ssh.ParsePrivateKey(pemBytes)
if err != nil {
log.Fatalf("parse key failed:%v", err)
}
config := &ssh.ClientConfig{
User: "ec2-user",
Auth: []ssh.AuthMethod{ssh.PublicKeys(signer)},
Timeout:Timeout,
}
return config,err
}
func Connect(){
config,_:= BastionConfig()
bClient, err := ssh.Dial("tcp", Bastion, config)
if err != nil {
log.Fatal("dial bastion error:",err)
}
log.Println("dial bastion ok...")
// Dial a connection to the service host, from the bastion
conn, err := bClient.Dial("tcp", Target)
if err != nil {
log.Fatal("dial target error",err)
}
targetConfig,_:= DestConfig()
ncc, chans, reqs, err := ssh.NewClientConn(conn, Target, targetConfig)
if err != nil {
log.Fatal("new target conn error:",err)
}
log.Printf("target conn[%s] ok\n",Target)
targetClient := ssh.NewClient(ncc, chans, reqs)
if err != nil {
log.Fatalf("target ssh error:%v",err)
}
session,err:=targetClient.NewSession()
if err!=nil{
log.Fatalf("session failed:%v",err)
}
defer session.Close()
var stdoutBuf bytes.Buffer
session.Stdout = &stdoutBuf
err = session.Run("hostname")
if err != nil {
log.Fatalf("Run failed:%v", err)
}
log.Printf(">%s", stdoutBuf)
}

But I got the hostname of the bastion server not my destination one,did I miss to lead the input/output of the destionation server or something, I don't know where is wrong for my code,Can anybody give me some directions.

thanks a lot.

Try this package https://github.com/appleboy/easyssh-proxy

ssh := &easyssh.MakeConfig{
User:    "drone-scp",
Server:  "localhost",
Port:    "22",
KeyPath: "./tests/.ssh/id_rsa",
Proxy: easyssh.DefaultConfig{
User:    "drone-scp",
Server:  "localhost",
Port:    "22",
KeyPath: "./tests/.ssh/id_rsa",
},
}

I've found my code is right. previously ,I was confused by the pem file locally. In my server configuration, the bastion and dest server ,the pem is quite different.so currently, the code is ok now. I can execute commands by logging into the target server with golang ssh.