Add support for setting stacks when creating session (#138)

* Add support for setting stacks when creating session

* Add exec endpoint and move dns stuff to another package

* Rename command and status code

api.go

@@ -4,10 +4,8 @@ import (
 	"crypto/tls"
 	"fmt"
 	"log"
-	"net"
 	"net/http"
 	"os"
-	"regexp"
 	"strings"
 
 	gh "github.com/gorilla/handlers"
@@ -28,7 +26,7 @@ func main() {
 	bypassCaptcha := len(os.Getenv("GOOGLE_RECAPTCHA_DISABLED")) > 0
 
 	// Start the DNS server
-	dns.HandleFunc(".", handleDnsRequest)
+	dns.HandleFunc(".", handlers.DnsRequest)
 	udpDnsServer := &dns.Server{Addr: ":53", Net: "udp"}
 	go func() {
 		err := udpDnsServer.ListenAndServe()
@@ -72,6 +70,7 @@ func main() {
 	corsRouter.HandleFunc("/sessions/{sessionId}", handlers.GetSession).Methods("GET")
 	corsRouter.HandleFunc("/sessions/{sessionId}/instances", handlers.NewInstance).Methods("POST")
 	corsRouter.HandleFunc("/sessions/{sessionId}/instances/{instanceName}", handlers.DeleteInstance).Methods("DELETE")
+	corsRouter.HandleFunc("/sessions/{sessionId}/instances/{instanceName}/exec", handlers.Exec).Methods("POST")
 	r.HandleFunc("/sessions/{sessionId}/instances/{instanceName}/keys", handlers.SetKeys).Methods("POST")
 
 	h := func(w http.ResponseWriter, r *http.Request) {
@@ -137,85 +136,3 @@ func main() {
 	}
 	log.Fatal(s.ListenAndServeTLS("", ""))
 }
-
-var dnsFilter = regexp.MustCompile(`pwd[0-9]{1,3}_[0-9]{1,3}_[0-9]{1,3}_[0-9]{1,3}`)
-
-func handleDnsRequest(w dns.ResponseWriter, r *dns.Msg) {
-	if len(r.Question) > 0 && dnsFilter.MatchString(r.Question[0].Name) {
-		// this is something we know about and we should try to handle
-		question := r.Question[0].Name
-		domainChunks := strings.Split(question, ".")
-		tldChunks := strings.Split(strings.TrimPrefix(domainChunks[0], "pwd"), "-")
-		ip := strings.Replace(tldChunks[0], "_", ".", -1)
-
-		m := new(dns.Msg)
-		m.SetReply(r)
-		m.Authoritative = true
-		m.RecursionAvailable = true
-		a, err := dns.NewRR(fmt.Sprintf("%s 60 IN A %s", question, ip))
-		if err != nil {
-			log.Fatal(err)
-		}
-		m.Answer = append(m.Answer, a)
-		w.WriteMsg(m)
-		return
-	} else {
-		if len(r.Question) > 0 {
-			question := r.Question[0].Name
-
-			if question == "localhost." {
-				log.Printf("Not a PWD host. Asked for [localhost.] returning automatically [127.0.0.1]\n")
-				m := new(dns.Msg)
-				m.SetReply(r)
-				m.Authoritative = true
-				m.RecursionAvailable = true
-				a, err := dns.NewRR(fmt.Sprintf("%s 60 IN A 127.0.0.1", question))
-				if err != nil {
-					log.Fatal(err)
-				}
-				m.Answer = append(m.Answer, a)
-				w.WriteMsg(m)
-				return
-			}
-
-			log.Printf("Not a PWD host. Looking up [%s]\n", question)
-			ips, err := net.LookupIP(question)
-			if err != nil {
-				// we have no information about this and we are not a recursive dns server, so we just fail so the client can fallback to the next dns server it has configured
-				w.Close()
-				// dns.HandleFailed(w, r)
-				return
-			}
-			log.Printf("Not a PWD host. Looking up [%s] got [%s]\n", question, ips)
-			m := new(dns.Msg)
-			m.SetReply(r)
-			m.Authoritative = true
-			m.RecursionAvailable = true
-			for _, ip := range ips {
-				ipv4 := ip.To4()
-				if ipv4 == nil {
-					a, err := dns.NewRR(fmt.Sprintf("%s 60 IN AAAA %s", question, ip.String()))
-					if err != nil {
-						log.Fatal(err)
-					}
-					m.Answer = append(m.Answer, a)
-				} else {
-					a, err := dns.NewRR(fmt.Sprintf("%s 60 IN A %s", question, ipv4.String()))
-					if err != nil {
-						log.Fatal(err)
-					}
-					m.Answer = append(m.Answer, a)
-				}
-			}
-			w.WriteMsg(m)
-			return
-
-		} else {
-			log.Printf("Not a PWD host. Got DNS without any question\n")
-			// we have no information about this and we are not a recursive dns server, so we just fail so the client can fallback to the next dns server it has configured
-			w.Close()
-			// dns.HandleFailed(w, r)
-			return
-		}
-	}
-}

handlers/dns.go

@@ -0,0 +1,93 @@
+package handlers
+
+import (
+	"fmt"
+	"log"
+	"net"
+	"regexp"
+	"strings"
+
+	"github.com/miekg/dns"
+)
+
+var dnsFilter = regexp.MustCompile(`pwd[0-9]{1,3}_[0-9]{1,3}_[0-9]{1,3}_[0-9]{1,3}`)
+
+func DnsRequest(w dns.ResponseWriter, r *dns.Msg) {
+	if len(r.Question) > 0 && dnsFilter.MatchString(r.Question[0].Name) {
+		// this is something we know about and we should try to handle
+		question := r.Question[0].Name
+		domainChunks := strings.Split(question, ".")
+		tldChunks := strings.Split(strings.TrimPrefix(domainChunks[0], "pwd"), "-")
+		ip := strings.Replace(tldChunks[0], "_", ".", -1)
+
+		m := new(dns.Msg)
+		m.SetReply(r)
+		m.Authoritative = true
+		m.RecursionAvailable = true
+		a, err := dns.NewRR(fmt.Sprintf("%s 60 IN A %s", question, ip))
+		if err != nil {
+			log.Fatal(err)
+		}
+		m.Answer = append(m.Answer, a)
+		w.WriteMsg(m)
+		return
+	} else {
+		if len(r.Question) > 0 {
+			question := r.Question[0].Name
+
+			if question == "localhost." {
+				log.Printf("Not a PWD host. Asked for [localhost.] returning automatically [127.0.0.1]\n")
+				m := new(dns.Msg)
+				m.SetReply(r)
+				m.Authoritative = true
+				m.RecursionAvailable = true
+				a, err := dns.NewRR(fmt.Sprintf("%s 60 IN A 127.0.0.1", question))
+				if err != nil {
+					log.Fatal(err)
+				}
+				m.Answer = append(m.Answer, a)
+				w.WriteMsg(m)
+				return
+			}
+
+			log.Printf("Not a PWD host. Looking up [%s]\n", question)
+			ips, err := net.LookupIP(question)
+			if err != nil {
+				// we have no information about this and we are not a recursive dns server, so we just fail so the client can fallback to the next dns server it has configured
+				w.Close()
+				// dns.HandleFailed(w, r)
+				return
+			}
+			log.Printf("Not a PWD host. Looking up [%s] got [%s]\n", question, ips)
+			m := new(dns.Msg)
+			m.SetReply(r)
+			m.Authoritative = true
+			m.RecursionAvailable = true
+			for _, ip := range ips {
+				ipv4 := ip.To4()
+				if ipv4 == nil {
+					a, err := dns.NewRR(fmt.Sprintf("%s 60 IN AAAA %s", question, ip.String()))
+					if err != nil {
+						log.Fatal(err)
+					}
+					m.Answer = append(m.Answer, a)
+				} else {
+					a, err := dns.NewRR(fmt.Sprintf("%s 60 IN A %s", question, ipv4.String()))
+					if err != nil {
+						log.Fatal(err)
+					}
+					m.Answer = append(m.Answer, a)
+				}
+			}
+			w.WriteMsg(m)
+			return
+
+		} else {
+			log.Printf("Not a PWD host. Got DNS without any question\n")
+			// we have no information about this and we are not a recursive dns server, so we just fail so the client can fallback to the next dns server it has configured
+			w.Close()
+			// dns.HandleFailed(w, r)
+			return
+		}
+	}
+}

handlers/exec.go

@@ -0,0 +1,40 @@
+package handlers
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+
+	"github.com/gorilla/mux"
+	"github.com/play-with-docker/play-with-docker/services"
+)
+
+type execRequest struct {
+	Cmd []string `json:"command"`
+}
+
+type execResponse struct {
+	ExitCode int `json:"status_code"`
+}
+
+func Exec(rw http.ResponseWriter, req *http.Request) {
+	vars := mux.Vars(req)
+	instanceName := vars["instanceName"]
+
+	var er execRequest
+	err := json.NewDecoder(req.Body).Decode(&er)
+	if err != nil {
+		rw.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	code, err := services.Exec(instanceName, er.Cmd)
+
+	if err != nil {
+		log.Println(err)
+		rw.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	json.NewEncoder(rw).Encode(execResponse{code})
+}

handlers/new_session.go

@@ -24,6 +24,7 @@ func NewSession(rw http.ResponseWriter, req *http.Request) {
 	}
 
 	reqDur := req.Form.Get("session-duration")
+	stack := req.Form.Get("stack")
 
 	duration := services.GetDuration(reqDur)
 	s, err := services.NewSession(duration)
@@ -31,7 +32,7 @@ func NewSession(rw http.ResponseWriter, req *http.Request) {
 		log.Println(err)
 		//TODO: Return some error code
 	} else {
-
+		s.StackFile = stack
 		hostname := fmt.Sprintf("%s.%s", config.PWDCName, req.Host)
 		// If request is not a form, return sessionId in the body
 		if req.Header.Get("X-Requested-With") == "XMLHttpRequest" {

services/docker.go

@@ -274,3 +274,20 @@ func CreateInstance(session *Session, dindImage string) (*Instance, error) {
 func DeleteContainer(id string) error {
 	return c.ContainerRemove(context.Background(), id, types.ContainerRemoveOptions{Force: true, RemoveVolumes: true})
 }
+
+func Exec(instanceName string, command []string) (int, error) {
+	e, err := c.ContainerExecCreate(context.Background(), instanceName, types.ExecConfig{Cmd: command})
+	if err != nil {
+		return 0, err
+	}
+	err = c.ContainerExecStart(context.Background(), e.ID, types.ExecStartCheck{})
+	if err != nil {
+		return 0, err
+	}
+	ins, err := c.ContainerExecInspect(context.Background(), e.ID)
+	if err != nil {
+		return 0, err
+	}
+	return ins.ExitCode, nil
+
+}

services/session.go

@@ -54,6 +54,7 @@ type Session struct {
 	scheduled    bool                 `json:"-"`
 	ticker       *time.Ticker         `json:"-"`
 	PwdIpAddress string               `json:"pwd_ip_address"`
+	StackFile    string               `json:"-"`
 }
 
 func (s *Session) Lock() {

www/bypass.html

@@ -11,6 +11,7 @@
             <h2>We're bypassing the Captcha and redirecting you now..</h2>
             <form id="welcomeFormBypass" method="POST" action="/">
                 <button id="start" type="submit">Start Session</button>
+                <input id="stack" type="hidden" name="stack" value=""/>
             </form>
         </div>
     </body>
@@ -21,4 +22,20 @@
     <script src="https://ajax.googleapis.com/ajax/libs/angular_material/1.1.0/angular-material.min.js"></script>
 
     <script src="/assets/app.js"></script>
+    <script>
+        function getParameterByName(name, url) {
+            if (!url) url = window.location.href;
+            name = name.replace(/[\[\]]/g, "\\$&");
+            var regex = new RegExp("[?&]" + name + "(=([^&#]*)|&|#|$)"),
+                results = regex.exec(url);
+            if (!results) return null;
+            if (!results[2]) return '';
+            return decodeURIComponent(results[2].replace(/\+/g, " "));
+        }
+
+        var stack = getParameterByName('stack');
+        if (stack) {
+            document.getElementById('stack').value = stack;
+        }
+    </script>
 </html>

www/welcome.html

@@ -14,6 +14,7 @@
             <form id="welcomeForm" method="POST" action="/">
                 <div id="recaptcha" class="g-recaptcha" data-callback="iAmHuman" data-sitekey="{{.}}"></div>
                 <input type="hidden" name="session-duration" value="4h"/>
+                <input id="stack" type="hidden" name="stack" value=""/>
                 <button id="create" style="display:none;">Create session</button>
             </form>
             <img src="/assets/large_h.png" />
@@ -23,6 +24,20 @@
             function iAmHuman(resp) {
                 document.getElementById('welcomeForm').submit();
             }
+            function getParameterByName(name, url) {
+                if (!url) url = window.location.href;
+                name = name.replace(/[\[\]]/g, "\\$&");
+                var regex = new RegExp("[?&]" + name + "(=([^&#]*)|&|#|$)"),
+                    results = regex.exec(url);
+                if (!results) return null;
+                if (!results[2]) return '';
+                return decodeURIComponent(results[2].replace(/\+/g, " "));
+            }
+
+            var stack = getParameterByName('stack');
+            if (stack) {
+                document.getElementById('stack').value = stack;
+            }
             if (document.cookie.indexOf('session_id') > -1) {
                 document.getElementById('create').style = "";
                 document.getElementById('recaptcha').style = "display:none;";