feat(UI) Handle starting/terminating states and block duplicate instance launches

D-VR · D-VR · commit c97e97b95966 · 2025-11-24T11:19:34.000+01:00
diff --git a/api/instance.py b/api/instance.py
@@ -140,10 +140,28 @@ def post():  # pylint: disable=too-many-return-statements,too-many-branches
                 return {"success": False, "data": {"message": "unauthorized"}}, 403
 
         # check if source_id can launch the instance
+        lock_acquired = False
+        lock = None
         try:
             lock = load_or_store(str(source_id))
             logger.debug("post /instance acquire the player lock for %s", source_id)
-            lock.player_lock()
+            lock_acquired = lock.player_lock(blocking=False)
+            if not lock_acquired:
+                logger.info(
+                    "instance creation already in progress for challenge %s / source %s",
+                    challenge_id,
+                    source_id,
+                )
+                return (
+                    {
+                        "success": False,
+                        "data": {
+                            "code": 6,
+                            "message": "instance creation already in progress",
+                        },
+                    },
+                    409,
+                )
 
             if not check_source_can_create_instance(challenge_id, source_id):
                 return (
@@ -186,8 +204,9 @@ def post():  # pylint: disable=too-many-return-statements,too-many-branches
             }, 500
 
         finally:
-            logger.debug("post /instance release the player lock for %s", source_id)
-            lock.player_unlock()
+            if lock_acquired and lock is not None:
+                logger.debug("post /instance release the player lock for %s", source_id)
+                lock.player_unlock(skip_rw=True)
 
         # return only necessary values
         data = {}
diff --git a/assets/view.js b/assets/view.js
@@ -13,6 +13,72 @@ CTFd._internal.challenge.postRender = function () {
 
 if (window.$ === undefined) window.$ = CTFd.lib.$;
 
+const BOOT_DEFAULT_LABEL = "Launch the challenge";
+const BOOT_STARTING_LABEL = "Starting...";
+const STARTING_KEY_PREFIX = "cm-starting:";
+const STARTING_TTL_MS = 10 * 60 * 1000;
+
+function getStartingKey(challengeId) {
+    return `${STARTING_KEY_PREFIX}${challengeId}`;
+}
+
+function markInstanceStarting(challengeId) {
+    try {
+        localStorage.setItem(
+            getStartingKey(challengeId),
+            JSON.stringify({ ts: Date.now() }),
+        );
+    } catch (e) {
+        // storage unavailable, nothing to do
+    }
+}
+
+function clearInstanceStarting(challengeId) {
+    try {
+        localStorage.removeItem(getStartingKey(challengeId));
+    } catch (e) {
+        // storage unavailable, nothing to do
+    }
+}
+
+function isInstanceStarting(challengeId) {
+    try {
+        const raw = localStorage.getItem(getStartingKey(challengeId));
+        if (!raw) return false;
+
+        const parsed = JSON.parse(raw);
+        if (!parsed.ts) return false;
+
+        const age = Date.now() - parsed.ts;
+        if (age > STARTING_TTL_MS) {
+            clearInstanceStarting(challengeId);
+            return false;
+        }
+        return true;
+    } catch (e) {
+        return false;
+    }
+}
+
+function setBootButtonStarting() {
+    $('#whale-button-boot').text(BOOT_STARTING_LABEL);
+    $('#whale-button-boot').prop('disabled', true);
+}
+
+function resetBootButton() {
+    $('#whale-button-boot').text(BOOT_DEFAULT_LABEL);
+    $('#whale-button-boot').prop('disabled', false);
+}
+
+function renderStartingState() {
+    $('#cm-panel-loading').hide();
+    $('#cm-panel-until').hide();
+    $('#whale-panel-started').hide();
+    $('#whale-panel-stopped').show();
+    $('#whale-challenge-lan-domain').html('');
+    setBootButtonStarting();
+}
+
 function formatCountDown(countdown) {
 
     // Convert
@@ -42,7 +108,12 @@ function formatCountDown(countdown) {
 function loadInfo() {
     var challenge_id = CTFd._internal.challenge.data.id;
     var url = "/api/v1/plugins/ctfd-chall-manager/instance?challengeId=" + challenge_id;
-
+    const pendingStart = isInstanceStarting(challenge_id);
+    if (pendingStart) {
+        setBootButtonStarting();
+    } else {
+        resetBootButton();
+    }
 
     CTFd.fetch(url, {
         method: 'GET',
@@ -67,11 +138,19 @@ function loadInfo() {
             clearInterval(window.t);
             window.t = undefined;
         }
-        if (response.success) response = response.data;
-        else CTFd._functions.events.eventAlert({
-            title: "Fail",
-            html: response.data.message,
-        });
+        if (response.success) {
+            response = response.data;
+            clearInstanceStarting(challenge_id);
+        } else {
+            const code = response.data?.code || response.code;
+            if (pendingStart && (code === 5 || code === 404 || code === 14)) {
+                renderStartingState();
+                return;
+            }
+            clearInstanceStarting(challenge_id);
+            renderErrorAlert(response);
+            return;
+        }
         $('#cm-panel-loading').hide();
         $('#cm-panel-until').hide(); 
        
@@ -100,9 +179,14 @@ function loadInfo() {
                     $('#whale-challenge-count-down').text(formatCountDown(count_down));
                 }, 1000);
             } else {
-                $('#whale-panel-started').hide(); // hide the panel instance is up       
-                $('#whale-panel-stopped').show(); // show the panel instance is down     
-                $('#whale-challenge-lan-domain').html(''); 
+                // expired but likely still being cleaned up server-side
+                $('#whale-panel-started').show(); // show the panel instance is up
+                $('#whale-panel-stopped').hide(); // hide the panel instance is down
+                $('#whale-challenge-lan-domain').html(response.connectionInfo || '');
+                $('#whale-challenge-count-down').text('terminating...');
+                $('#cm-panel-until').show();
+                // prevent booting a second instance while termination pending
+                $('#whale-button-boot').prop('disabled', true).text('Terminating...');
             }
                     
         } else if (response.since) {    // if instance has no until
@@ -113,6 +197,7 @@ function loadInfo() {
             $('#whale-panel-started').hide(); // hide the panel instance is up       
             $('#whale-panel-stopped').show(); // show the panel instance is down     
             $('#whale-challenge-lan-domain').html(''); 
+            resetBootButton();
         }
  
         
@@ -261,6 +346,8 @@ CTFd._internal.challenge.boot = function() {
 
         $('#whale-button-boot').text("Waiting...");
         $('#whale-button-boot').prop('disabled', true);
+        markInstanceStarting(challenge_id);
+        setBootButtonStarting();
 
         var params = {
             "challengeId": challenge_id.toString()
@@ -286,18 +373,13 @@ CTFd._internal.challenge.boot = function() {
                     title: "Success",
                     html: "Your instance has been deployed!",
                 });
+                clearInstanceStarting(challenge_id);
                 resolve();
             } else {
-                CTFd._functions.events.eventAlert({
-                    title: "Fail",
-                    html: response.data.message,
-                });
-            }
-        }).catch(error => {
+
             reject(error);
-        }).finally(() => {
-            $('#whale-button-boot').text("Launch an instance");
-            $('#whale-button-boot').prop('disabled', false);
+        }.finally(() => {
+            resetBootButton();
         });
     });
 };
@@ -352,4 +434,4 @@ CTFd._internal.challenge.submit = function(preview) {
         }
         return response
     })
-};
+};
diff --git a/utils/mana_lock.py b/utils/mana_lock.py
@@ -56,22 +56,33 @@ def __init__(self, name: str):
     def __repr__(self):
         return f"ManaLock name={self.name}"
 
-    def player_lock(self):
+    def player_lock(self, blocking: bool = True) -> bool:
         """
         Acquires the lock for a player.
+
+        ``blocking`` (bool): attempt to acquire without waiting when False.
+
+        Returns True if the lock was acquired, False otherwise.
         """
+        if not blocking:
+            return self.gr.acquire(blocking=False)
+
         if rw_lock_enabled:
             self.rw.r_lock()
 
         self.gr.acquire()
+        return True
 
-    def player_unlock(self):
+    def player_unlock(self, *, skip_rw: bool = False):
         """
         Releases the lock for a player.
+
+        ``skip_rw`` (bool): if True, do not release the RW lock
+        (used when ``player_lock`` was called with ``blocking=False``).
         """
         self.gr.release()
 
-        if rw_lock_enabled:
+        if rw_lock_enabled and not skip_rw:
             self.rw.r_unlock()
 
     def admin_lock(self):
