MODCLUSTER-790 mod_cluster listener throws NPE when deploying a conte…

…xt in Tomcat
modcluster · Jul 25, 2023 · 1a96bf2 · 1a96bf2
1 parent 4d2dc2a
commit 1a96bf2
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Showing 2 changed files with 21 additions and 5 deletions.
diff --git a/container/spi/src/main/java/org/jboss/modcluster/container/Context.java b/container/spi/src/main/java/org/jboss/modcluster/container/Context.java
@@ -52,6 +52,18 @@ public interface Context {
      */
     boolean isStarted();
 
+    /**
+     * Returns whether this context is suspended. A suspended context is not available for processing requests,
+     * but it could be made available at later time. This translates into the context be made known to reverse proxies
+     * but in a stopped state. Implementing this method is optional defaulting to suspended mode not being supported
+     * by the container.
+     *
+     * @return whether this context is suspended
+     */
+    default boolean isSuspended() {
+        return false;
+    }
+
     /**
      * Registers the specified request listener with this context. Used for request draining.
      *

diff --git a/core/src/main/java/org/jboss/modcluster/ModClusterService.java b/core/src/main/java/org/jboss/modcluster/ModClusterService.java
@@ -300,11 +300,15 @@ public void add(Context context) {
         ModClusterLogger.LOGGER.addContext(context.getHost(), context);
 
         if (this.include(context) && this.established) {
-            // Send ENABLE-APP if state is started
-            if (context.isStarted()) {
-                this.enable(context);
-            } else {
+            if (context.isSuspended()) {
+                // Send STOP-APP if the context is suspended
                 this.stop(context);
+            } else if (context.isStarted()) {
+                // Send ENABLE-APP if state is started
+
+                // n.b. for some containers like Tomcat, the context at this point is only in the 'STARTING' state and
+                // thus enable(..) will not be called here but rather during a start(..) call.
+                this.enable(context);
             }
         }
     }
@@ -313,7 +317,7 @@ public void add(Context context) {
     public void start(Context context) {
         ModClusterLogger.LOGGER.startContext(context.getHost(), context);
 
-        if (this.include(context)) {
+        if (this.include(context) && !context.isSuspended()) {
             if (this.established) {
                 this.enable(context);
             }