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

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" {