Add ssh proxy

Dockerfile

@@ -10,14 +10,18 @@ WORKDIR /go/src/github.com/play-with-docker/play-with-docker
 
 RUN go get -v -d ./...
 
+RUN ssh-keygen -N "" -t rsa -f /etc/ssh/ssh_host_rsa_key >/dev/null
+
 RUN CGO_ENABLED=0 go build -a -installsuffix nocgo -o /go/bin/play-with-docker .
 
+
 FROM alpine
 
 RUN apk --update add ca-certificates
 RUN mkdir -p /app/pwd
 
 COPY --from=0 /go/bin/play-with-docker /app/play-with-docker
+COPY --from=0 /etc/ssh/ssh_host_rsa_key /etc/ssh/ssh_host_rsa_key
 COPY ./www /app/www
 
 WORKDIR /app

api.go

@@ -111,6 +111,8 @@ func main() {
 		log.Fatal(httpServer.ListenAndServe())
 	}()
 
+	go handlers.ListenSSHProxy("0.0.0.0:1022")
+
 	// Now listen for TLS connections that need to be proxied
 	handlers.StartTLSProxy(config.SSLPortNumber)
 }

docker-compose.yml

@@ -15,7 +15,7 @@ services:
         # use the latest golang image
         image: golang
         # go to the right place and starts the app
-        command: /bin/sh -c 'cd /go/src/github.com/play-with-docker/play-with-docker; go run api.go -save /pwd/sessions1 -name pwd1 -cname host1'
+        command: /bin/sh -c 'ssh-keygen -N "" -t rsa -f /etc/ssh/ssh_host_rsa_key >/dev/null; cd /go/src/github.com/play-with-docker/play-with-docker; go run api.go -save /pwd/sessions1 -name pwd1 -cname host1'
         volumes:
             # since this app creates networks and launches containers, we need to talk to docker daemon
             - /var/run/docker.sock:/var/run/docker.sock
@@ -24,13 +24,15 @@ services:
             - sessions:/pwd
         environment:
             GOOGLE_RECAPTCHA_DISABLED: "true"
+        ports:
+            - "1022:1022"
     pwd2:
         # pwd daemon container always needs to be named this way
         container_name: pwd2
         # use the latest golang image
         image: golang
         # go to the right place and starts the app
-        command: /bin/sh -c 'cd /go/src/github.com/play-with-docker/play-with-docker; go run api.go -save /pwd/sessions2 -name pwd2 -cname host2'
+        command: /bin/sh -c 'ssh-keygen -N "" -t rsa -f /etc/ssh/ssh_host_rsa_key >/dev/null; cd /go/src/github.com/play-with-docker/play-with-docker; go run api.go -save /pwd/sessions2 -name pwd2 -cname host2'
         volumes:
             # since this app creates networks and launches containers, we need to talk to docker daemon
             - /var/run/docker.sock:/var/run/docker.sock
@@ -39,6 +41,8 @@ services:
             - sessions:/pwd
         environment:
             GOOGLE_RECAPTCHA_DISABLED: "true"
+        ports:
+            - "1023:1022"
     prometheus:
         container_name: prometheus
         image: prom/prometheus

handlers/sshproxy.go

@@ -0,0 +1,206 @@
+package handlers
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net"
+	"strings"
+	"sync"
+
+	"golang.org/x/crypto/ssh"
+)
+
+var sshConfig = &ssh.ServerConfig{
+	PublicKeyCallback: func(c ssh.ConnMetadata, pubKey ssh.PublicKey) (*ssh.Permissions, error) {
+		user := c.User()
+		chunks := strings.Split(user, "-")
+		ip := strings.Join(chunks[:4], ".")
+		sessionPrefix := chunks[4]
+
+		log.Println(ip, sessionPrefix)
+
+		return nil, nil
+	},
+}
+
+func ListenSSHProxy(laddr string) {
+	privateBytes, err := ioutil.ReadFile("/etc/ssh/ssh_host_rsa_key")
+	if err != nil {
+		log.Fatal("Failed to load private key: ", err)
+	}
+
+	private, err := ssh.ParsePrivateKey(privateBytes)
+	if err != nil {
+		log.Fatal("Failed to parse private key: ", err)
+	}
+
+	sshConfig.AddHostKey(private)
+
+	listener, err := net.Listen("tcp", laddr)
+	if err != nil {
+		log.Fatal("failed to listen for connection: ", err)
+	}
+	for {
+		nConn, err := listener.Accept()
+		if err != nil {
+			log.Fatal("failed to accept incoming connection: ", err)
+		}
+
+		go handle(nConn)
+	}
+}
+
+func handle(c net.Conn) {
+	sshCon, chans, reqs, err := ssh.NewServerConn(c, sshConfig)
+	if err != nil {
+		c.Close()
+		return
+	}
+
+	user := sshCon.User()
+	chunks := strings.Split(user, "-")
+	ip := strings.Join(chunks[:4], ".")
+	sessionPrefix := chunks[4]
+
+	i := core.InstanceFindByIPAndSession(sessionPrefix, ip)
+	if i == nil {
+		log.Printf("Couldn't find instance with ip [%s] in session [%s]\n", ip, sessionPrefix)
+		c.Close()
+		return
+	}
+
+	// The incoming Request channel must be serviced.
+	go ssh.DiscardRequests(reqs)
+
+	newChannel := <-chans
+	if newChannel == nil {
+		sshCon.Close()
+		return
+	}
+
+	if newChannel.ChannelType() != "session" {
+		newChannel.Reject(ssh.UnknownChannelType, "unknown channel type")
+		return
+	}
+
+	channel, requests, err := newChannel.Accept()
+	if err != nil {
+		log.Fatalf("Could not accept channel: %v", err)
+	}
+
+	stderr := channel.Stderr()
+
+	fmt.Fprintf(stderr, "Connecting to %s\r\n", ip)
+
+	clientConfig := &ssh.ClientConfig{
+		User: "root",
+		Auth: []ssh.AuthMethod{
+			ssh.Password("root"),
+		},
+		HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
+			return nil
+		},
+	}
+
+	client, err := ssh.Dial("tcp", fmt.Sprintf("%s:22", ip), clientConfig)
+	if err != nil {
+		fmt.Fprintf(stderr, "Connect failed: %v\r\n", err)
+		channel.Close()
+		return
+	}
+
+	go func() {
+		for newChannel = range chans {
+			if newChannel == nil {
+				return
+			}
+
+			channel2, reqs2, err := client.OpenChannel(newChannel.ChannelType(), newChannel.ExtraData())
+			if err != nil {
+				x, ok := err.(*ssh.OpenChannelError)
+				if ok {
+					newChannel.Reject(x.Reason, x.Message)
+				} else {
+					newChannel.Reject(ssh.Prohibited, "remote server denied channel request")
+				}
+				continue
+			}
+
+			channel, reqs, err := newChannel.Accept()
+			if err != nil {
+				channel2.Close()
+				continue
+			}
+			go proxy(reqs, reqs2, channel, channel2)
+		}
+	}()
+
+	// Forward the session channel
+	channel2, reqs2, err := client.OpenChannel("session", []byte{})
+	if err != nil {
+		fmt.Fprintf(stderr, "Remote session setup failed: %v\r\n", err)
+		channel.Close()
+		return
+	}
+
+	maskedReqs := make(chan *ssh.Request, 1)
+	go func() {
+		for req := range requests {
+			if req.Type == "auth-agent-req@openssh.com" {
+				continue
+			}
+			maskedReqs <- req
+		}
+	}()
+	proxy(maskedReqs, reqs2, channel, channel2)
+}
+
+func proxy(reqs1, reqs2 <-chan *ssh.Request, channel1, channel2 ssh.Channel) {
+	var closer sync.Once
+	closeFunc := func() {
+		channel1.Close()
+		channel2.Close()
+	}
+
+	defer closer.Do(closeFunc)
+
+	closerChan := make(chan bool, 1)
+
+	go func() {
+		io.Copy(channel1, channel2)
+		closerChan <- true
+	}()
+
+	go func() {
+		io.Copy(channel2, channel1)
+		closerChan <- true
+	}()
+
+	for {
+		select {
+		case req := <-reqs1:
+			if req == nil {
+				return
+			}
+			b, err := channel2.SendRequest(req.Type, req.WantReply, req.Payload)
+			if err != nil {
+				return
+			}
+			req.Reply(b, nil)
+
+		case req := <-reqs2:
+			if req == nil {
+				return
+			}
+			b, err := channel1.SendRequest(req.Type, req.WantReply, req.Payload)
+			if err != nil {
+				return
+			}
+			req.Reply(b, nil)
+		case <-closerChan:
+			return
+		}
+	}
+}

pwd/instance.go

@@ -150,6 +150,20 @@ func (p *pwd) InstanceFindByIP(ip string) *Instance {
 	return nil
 }
 
+func (p *pwd) InstanceFindByIPAndSession(sessionPrefix, ip string) *Instance {
+	defer observeAction("InstanceFindByIPAndSession", time.Now())
+	for id, s := range sessions {
+		if strings.HasPrefix(id, sessionPrefix) {
+			for _, i := range s.Instances {
+				if i.IP == ip {
+					return i
+				}
+			}
+		}
+	}
+	return nil
+}
+
 func (p *pwd) InstanceFindByAlias(sessionPrefix, alias string) *Instance {
 	defer observeAction("InstanceFindByAlias", time.Now())
 	for id, s := range sessions {

pwd/pwd.go

@@ -68,6 +68,7 @@ type PWDApi interface {
 	InstanceGet(session *Session, name string) *Instance
 	InstanceFindByIP(ip string) *Instance
 	InstanceFindByAlias(sessionPrefix, alias string) *Instance
+	InstanceFindByIPAndSession(sessionPrefix, ip string) *Instance
 	InstanceDelete(session *Session, instance *Instance) error
 	InstanceWriteToTerminal(instance *Instance, data string)
 	InstanceAllowedImages() []string