weird nil pointer deref

.vagrant/machines/default/libvirt/created_networks

@@ -8,3 +8,7 @@
 5533801d-70e3-4c21-9942-82d20930c789
 5533801d-70e3-4c21-9942-82d20930c789
 5533801d-70e3-4c21-9942-82d20930c789
+5533801d-70e3-4c21-9942-82d20930c789
+5533801d-70e3-4c21-9942-82d20930c789
+5533801d-70e3-4c21-9942-82d20930c789
+5533801d-70e3-4c21-9942-82d20930c789

README.md

@@ -8,11 +8,18 @@ Users to use Webtop in their own, separate session. A good illustration is this:
 To build the project, you can just use "make"
 
 On Debian 12, you will need the following dependencies:
-```
+```sh
 apt install -y git wget podman make gcc libgpgme-dev build-essential pkgconf pkgconf-bin libdevmapper-dev libbtrfs-dev
 ```
 
-## Running
+## Installing
-To run the built binary, just execute it as root. You will have to have Podman installed and its socket enabled.
+Executing `make install` will install and start podterminal as a systemd service, including an example config file.
-Currently you have to set the Image, port etc. directly in the Source Code, however that should be eventually moved into
+
-a config file.
+## Usage
+There is some basic Documentation in the config file to explain the usage of the keys. For more in-depth explanations 
+feel free to contact me, and I will add it to the documentation
+
+## Known Bugs
+- Images need to be pulled first as root
+- Not compatible with default KASM Docker images (needs http WSS access)
+- reloading browser on startup might be necessary, especially if the target image is slow to start

exampleconfig.yaml

@@ -9,19 +9,20 @@ envvars:
     # HTTP_PROXY: 192.168.0.10
 
 # Container Image you want to use
-image: lscr.io/linuxserver/webtop
+image: git.jmbit.de/jmb/webtop-plus:latest
 # Maximum age of Session
-maxage: 10800
+maxage: 0
 # Port Podterminal should listen to
 port: 80
 # Files that will be copied into container on startup
 skel: /etc/podterminal/skel.tar.gz
 skel_target: /config
-skel_chown: true
+# Overrides UID/GID from tar archive to container user
-# Currently useless
+skel_chown: false
-skel_owner: "abc"
 ssl: false
 ssl_cert: /etc/ssl/certs/ssl-cert-snakeoil.pem
 ssl_cert_key: /etc/ssl/private/ssl-cert-snakeoil.key
 # Blocks accessing /files and /files/socket.io to avoid File transfer
 block_filebrowser: false
+# Delete running containers when restarting podterminal
+timeout_on_restart: true

main.go

@@ -25,6 +25,7 @@ func main() {
 	log.Println("Dropped Privileges")
 	g.Go(pods.GarbageCollector)
 	g.Go(pods.PullImage)
+	g.Go(web.IdleSessionCleanup)
 
 	// prevent main thread from dying
 	if err := g.Wait(); err != nil {

pods/container.go

@@ -2,6 +2,7 @@ package pods
 
 import (
 	"log"
+	"time"
 
 	"github.com/containers/podman/v4/pkg/bindings/containers"
 	"github.com/containers/podman/v4/pkg/specgen"
@@ -9,6 +10,8 @@ import (
 	"github.com/spf13/viper"
 )
 
+// CreateContainer connects to the Podman socket defined in the "Socket" variable in this scope
+// and creates a new container using the Image defined in the config file
 func CreateContainer() (string, error) {
 	image := viper.GetString("image")
 	conn := Socket
@@ -50,15 +53,30 @@ func DestroyContainer(id string) error {
 	return nil
 }
 
+// GetContainerIP returns a
 func GetContainerIP(id string) (string, error) {
 	conn := Socket
+	var ip string
+	var err error
+	i := 0
 
-	container, err := containers.Inspect(conn, id, nil)
+	for i < 50 {
-	if err != nil {
+		time.Sleep(100 * time.Millisecond)
-		log.Println("Could not get IP of container", err)
+		container, err := containers.Inspect(conn, id, nil)
-		return "", err
+		if err != nil {
+			log.Println("Could not get IP of container", err)
+			return "", err
+		}
+		ip = container.NetworkSettings.IPAddress
+		log.Println(ip)
+		if len(ip) > 5 {
+			break
+		}
+		i++
+	}
+	if i > 50 {
+		log.Println("timed out waiting for IP")
 	}
-	ip := container.NetworkSettings.IPAddress
 
 	return ip, err
 }

pods/garbageCollector.go

@@ -1,10 +1,18 @@
 package pods
 
 import (
+	"log"
 	"time"
+
+	"github.com/containers/podman/v4/pkg/bindings/volumes"
+	"github.com/spf13/viper"
 )
 
+// GarbageCollector is a goroutine that cleans up old Containers
 func GarbageCollector() error {
+	if viper.GetBool("timeout_on_restart") {
+		timeoutExistingContainers()
+	}
 	for {
 		err := Cleanup()
 		if err != nil {
@@ -13,3 +21,28 @@ func GarbageCollector() error {
 		time.Sleep(time.Minute * 10)
 	}
 }
+
+func timeoutExistingContainers() {
+	var oldContainers []string
+
+	for _, container := range containerList() {
+		oldContainers = append(oldContainers, container.ID)
+	}
+	OldContainers = append(OldContainers, oldContainers...)
+	log.Println("old Containers: ", oldContainers)
+
+}
+
+func pruneVolumes() error {
+
+	results, err := volumes.Prune(Socket, nil)
+	if err != nil {
+		return err
+	}
+	resultLen := len(results)
+	for i, result := range results {
+		log.Printf("[%d/%d] %s %d MB", i, resultLen, result.Id, result.Size/1024/1024)
+	}
+	return nil
+
+}

pods/manager.go

@@ -3,7 +3,6 @@ package pods
 import (
 	"context"
 	"log"
-	"net"
 	"time"
 
 	"github.com/containers/podman/v4/pkg/bindings"
@@ -14,7 +13,8 @@ import (
 )
 
 var Socket context.Context
-var rawSocket net.Conn
+
+var OldContainers []string
 
 func socketConnection() context.Context {
 	uri := "unix:///run/podman/podman.sock"
@@ -25,31 +25,24 @@ func socketConnection() context.Context {
 	return conn
 }
 
-func rawConnection() net.Conn {
-	connection, err := net.Dial("unix", "unix:///run/podman/podman.sock")
-	if err != nil {
-		log.Println(
-			"Could not establish raw UNIX socket connection, certain features will not work properly",
-		)
-	}
-	return connection
-}
-
 func ConnectSocket() {
 	Socket = socketConnection()
-	rawSocket = rawConnection()
 }
 
 func PullImage() error {
-	log.Println("Downloading Container image ", viper.GetString("image"))
+	for {
-	image := viper.GetString("image")
+		log.Println("Downloading Container image ", viper.GetString("image"))
-	conn := Socket
+		image := viper.GetString("image")
-	_, err := images.Pull(conn, image, nil)
+		conn := Socket
-	if err != nil {
+		_, err := images.Pull(conn, image, nil)
-		log.Println(err)
+		if err != nil {
-		return err
+			log.Println(err)
+			return err
+		}
+
+		time.Sleep(1 * time.Hour)
 	}
-	return nil
+
 }
 
 // Cleanup deletes Containers older than the specified maximum Age (Equal to session cookie maximum age)
@@ -58,22 +51,21 @@ func Cleanup() error {
 	containerList := containerList()
 
 	for _, container := range containerList {
-		now := time.Now()
+		for _, ctid := range OldContainers {
-		maxAge := time.Second * time.Duration(viper.GetInt("maxAge"))
+			if container.ID == ctid {
-		containerAge := now.Sub(container.Created)
+				err := containers.Kill(Socket, container.ID, nil)
-		if containerAge > maxAge {
+				if err != nil {
-
+					log.Println(err)
-			err := containers.Kill(Socket, container.ID, nil)
+					return err
-			if err != nil {
+				}
-				log.Println(err)
+				_, err = containers.Remove(Socket, container.ID, nil)
-				return err
+				if err != nil {
-			}
+					log.Println(err)
-			_, err = containers.Remove(Socket, container.ID, nil)
+					return err
-			if err != nil {
+				}
-				log.Println(err)
-				return err
 			}
 		}
+
 	}
 	return nil
 }

pods/skel.go

@@ -1,10 +1,13 @@
 package pods
 
 import (
+	"bytes"
 	"fmt"
+	"io"
 	"log"
 	"net/http"
 	"os"
+	"strings"
 
 	"github.com/containers/podman/v4/pkg/bindings"
 	"github.com/containers/podman/v4/pkg/bindings/containers"
@@ -65,7 +68,36 @@ func CopySkelToContainer(id string) error {
 		return err
 	}
 	log.Println(response.StatusCode, response.Body)
+	if viper.GetString("skel_user") != "" {
+		chownSkel(id)
+
+	}
 
 	// Manually chown the Directory, because podmans chown is sometimes unreliable
 	return response.Process(nil)
 }
+
+func chownSkel(id string) {
+	command := fmt.Sprintf(
+		"chown -R %s %s \n\n",
+		viper.GetString("skel_user"),
+		viper.GetString("skel_target"),
+	)
+	done := make(chan bool)
+	detachKeys := "\n\n"
+	commandReader := strings.NewReader(command)
+	var output bytes.Buffer
+	outputWriter := io.Writer(&output)
+	options := &containers.AttachOptions{
+		DetachKeys: &detachKeys,
+	}
+
+	err := containers.Attach(Socket, id, commandReader, outputWriter, outputWriter, done, options)
+
+	if err != nil {
+		log.Printf("Error: %v \n %s\n", err, output.String())
+	} else {
+		log.Println(output.String())
+	}
+
+}

readConfig.go

@@ -5,22 +5,29 @@ import (
 	"os"
 
 	"github.com/spf13/viper"
+
+	"git.jmbit.de/jmb/podterminal/utils"
 )
 
 func readConfigFile() {
+	sessionKey, _ := utils.RandomString(64)
 	log.Println("Reading Config")
 	viper.SetConfigFile("/etc/podterminal/config.yaml")
 	viper.SetDefault("port", 80)
 	viper.SetDefault("ip_addr", "0.0.0.0")
-	viper.SetDefault("image", "lscr.io/linuxserver/webtop")
+	viper.SetDefault("image", "git.jmbit.de/jmb/webtop-plus:latest")
 	viper.SetDefault("maxAge", 10800)
 	viper.SetDefault("dri", false)
 	viper.SetDefault("dir_node", "/dev/dri/renderD128")
 	viper.SetDefault("skel", "/etc/podterminal/skel.tar.gz")
 	viper.SetDefault("skel_chown", false)
 	viper.SetDefault("skel_target", "/")
-	viper.SetDefault("skel_owner", "abc")
+	viper.SetDefault("skel_user", "")
 	viper.SetDefault("block_filebrowser", false)
+	viper.SetDefault("session_key", sessionKey)
+	viper.SetDefault("container_port", 3000)
+	viper.SetDefault("container_protocol", "http")
+	viper.SetDefault("timeout_on_restart", true)
 	viper.SetDefault("envvars",
 		map[string]string{
 			"CUSTOM_USER": "user",

web/responses.go

@@ -0,0 +1,18 @@
+package web
+
+var clientReloadContent = `
+<!DOCTYPE html>
+<html>
+  <head>
+    <title> Reloading </title>  
+  </head>
+  <body>
+    reloading
+  </body>
+  <script>
+    setTimeout(() => {
+      document.location.reload();
+    }, 3000);
+  </script>
+</html>
+`

web/reverseProxy.go

@@ -3,12 +3,14 @@ package web
 import (
 	"fmt"
 	"log"
+	"net/http"
 	"net/http/httputil"
 	"net/url"
 	"time"
 
 	"github.com/gin-contrib/sessions"
 	"github.com/gin-gonic/gin"
+	"github.com/spf13/viper"
 
 	"git.jmbit.de/jmb/podterminal/pods"
 )
@@ -27,6 +29,15 @@ func createReverseProxy(backendService string) (*httputil.ReverseProxy, error) {
 			request.SetURL(backendURL)
 			request.Out.Host = request.In.Host
 		},
+		//	ModifyResponse: func(response *http.Response) error {
+		//		if response.StatusCode == http.StatusBadGateway {
+		//			waitForAnswer(backendURL.String())
+		//			response.StatusCode = 200
+		//			response.Header.Set("Location", "/")
+
+		//		}
+		//		return nil
+		//	},
 	}
 
 	return proxy, err
@@ -34,33 +45,48 @@ func createReverseProxy(backendService string) (*httputil.ReverseProxy, error) {
 
 func containerProxy(c *gin.Context) {
 	session := sessions.Default(c)
-	session.Save()
+	sessionID := ""
-	sessionID := session.ID()
 	if session.Get("ct") == nil {
+		session.Set("ready", false)
+		session.Save()
 		log.Println("Creating Container for Session ", sessionID)
 		ct, err := pods.CreateContainer()
+		session.Set("ct", ct)
+		session.Save()
 		if err != nil {
 			c.HTML(500, "Error", fmt.Sprintf("[%s] Could not create Container: %v", sessionID, err))
+			session.Delete("ct")
+			session.Save()
 			c.Abort()
+			return
 		}
 		err = pods.StartContainer(ct)
 		if err != nil {
 			c.HTML(500, "Error", fmt.Sprintf("[%s] Could not start Container: %v", sessionID, err))
+			session.Delete("ct")
+			session.Save()
 			c.Abort()
+
+			return
 		}
-		// Hack to wait for Container to start up and get assigned an IP
+
-		time.Sleep(3 * time.Second)
 		ctip, err := pods.GetContainerIP(ct)
 
 		if err != nil {
 			c.HTML(500, "Error", fmt.Sprintf("[%s] Could not get Container ip: %v", sessionID, err))
+			session.Delete("ct")
+			session.Save()
 			c.Abort()
+			return
 		}
 
 		// Soft fail Skel
-		_ = pods.CopySkelToContainer(ct)
+		// _ = pods.CopySkelToContainer(ct)
 
-		proxies[ct], err = createReverseProxy(fmt.Sprintf("http://%s:3000", ctip))
+		err = waitForAnswer(fmt.Sprintf("http://%s:%d", ctip, viper.GetInt("container_port")))
+		proxies[ct], err = createReverseProxy(
+			fmt.Sprintf("http://%s:%d", ctip, viper.GetInt("container_port")),
+		)
 
 		if err != nil {
 			c.HTML(
@@ -68,23 +94,65 @@ func containerProxy(c *gin.Context) {
 				"Error",
 				fmt.Sprintf("[%s] Could not create Container Proxy: %v", sessionID, err),
 			)
+			session.Delete("ct")
+			session.Save()
 			c.Abort()
+			return
 		}
-		session.Set("ct", ct)
+		if err != nil {
-		session.Save()
+			c.HTML(
-		c.Redirect(301, "/")
+				500,
-	} else {
+				"Error",
-		sessionCT := session.Get("ct")
+				fmt.Sprintf("[%s] Timed out waiting for Container: %v", sessionID, err),
-		switch sessionCT.(type) {
+			)
-		case string:
+			session.Delete("ct")
-
+			session.Save()
-		default:
-			c.HTML(500, "Error", "Session Container ID is not a string")
 			c.Abort()
+			return
+		}
+		session.Set("ready", true)
+		session.Save()
+		c.HTML(200, "", clientReloadContent)
+		return
+	} else {
+		if session.Get("ready").(bool) == false {
+			time.Sleep(2 * time.Second)
+			c.Redirect(307, "/")
+			return
 		}
 		id := session.Get("ct").(string)
 		proxy := proxies[id]
-		proxy.ServeHTTP(c.Writer, c.Request)
+		if proxy != nil {
+			proxy.ServeHTTP(c.Writer, c.Request)
+		} else {
+			session.Delete("ct")
+			session.Delete("ready")
+			session.Save()
+			c.Abort()
+			return
+		}
+
 	}
 
 }
+
+func waitForAnswer(url string) error {
+	retries := 0
+	var err error
+	for retries < 50 {
+		err = nil
+		response, err := http.Get(url)
+		if err != nil {
+			log.Printf("Error connecting to %s: %v", url, err)
+		}
+		if response.StatusCode == 200 {
+			return nil
+		}
+
+		retries++
+		time.Sleep(500 * time.Millisecond)
+	}
+	log.Println("Timed out waiting for Container")
+	return err
+
+}

web/router.go

@@ -8,7 +8,6 @@ import (
 	"github.com/gin-contrib/sessions"
 	"github.com/gin-contrib/sessions/cookie"
 	"github.com/gin-gonic/gin"
-	"github.com/google/uuid"
 	"github.com/spf13/viper"
 )
 
@@ -42,7 +41,7 @@ func setupRouter() *gin.Engine {
 	gin.ForceConsoleColor()
 	gin.SetMode("release")
 	router := gin.New()
-	store := cookie.NewStore([]byte(uuid.NewString()))
+	store := cookie.NewStore([]byte(viper.GetString("session_key")))
 	store.Options(sessions.Options{
 		MaxAge: viper.GetInt("maxAge"),
 	})

web/sessionAging.go

@@ -0,0 +1,60 @@
+package web
+
+import (
+	"log"
+	"time"
+
+	"github.com/spf13/viper"
+
+	"git.jmbit.de/jmb/podterminal/pods"
+)
+
+type sessionData struct {
+	lastAccess *time.Time
+	sessionID  string
+}
+
+var invalidSessions []string
+var sessionLastAccess map[string]*sessionData
+
+func initSessionAging() error {
+	sessionLastAccess = make(map[string]*sessionData)
+
+	return nil
+}
+
+func updateSession(id string, sessionID string) {
+	nowTime := time.Now()
+	sessionLastAccess[id].lastAccess = &nowTime
+	sessionLastAccess[id].sessionID = sessionID
+}
+
+func deleteIdleSessions() {
+	idleTimout := viper.GetInt("session_timeout")
+	tenMinutesAgo := -time.Duration(idleTimout) * time.Second
+	oldAge := time.Now().Add(tenMinutesAgo)
+	for session, sessionData := range sessionLastAccess {
+		log.Printf("Session %s last connected at %s", session, sessionData.lastAccess.String())
+		if oldAge.After(*sessionData.lastAccess) {
+			pods.DestroyContainer(session)
+			invalidSessions = append(invalidSessions, sessionData.sessionID)
+			// Delete Proxy entry to avoid 502s
+			delete(proxies, session)
+
+		}
+
+	}
+
+}
+
+func IdleSessionCleanup() error {
+	err := initSessionAging()
+	if err != nil {
+		println("Could not initialize Session aging")
+		return err
+	}
+	for {
+		deleteIdleSessions()
+		time.Sleep(time.Duration(viper.GetInt("session_timeout")) * time.Second)
+	}
+}