From e7f9ea2cd02cc8ffb743cff4d07ba7068d1e7c73 Mon Sep 17 00:00:00 2001
From: Tomas Cere <tomas.cere@pantheon.tech>
Date: Mon, 7 Jan 2019 11:21:09 +0100
Subject: [PATCH] Prevent ssh hang during shutdown

Add a reference listener for netty executor service provided by blueprint
so we can close ssh servers while the bundle still exists. This prevents
the hang seen during shutdown since the executor was being shutdown before
the mdsal-netconf-ssh.

JIRA: NETCONF-577
Change-Id: I062c9e8afb349817435ea0b1dde796a54ebb22d2
Signed-off-by: Tomas Cere <tomas.cere@pantheon.tech>
---
 netconf/mdsal-netconf-ssh/pom.xml                 |  5 +++++
 .../org/opendaylight/blueprint/netconf-ssh.xml    |  5 ++++-
 .../netconf/ssh/NetconfNorthboundSshServer.java   | 15 +++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/netconf/mdsal-netconf-ssh/pom.xml b/netconf/mdsal-netconf-ssh/pom.xml
index ff13ec2eaf..2e9a06a44b 100644
--- a/netconf/mdsal-netconf-ssh/pom.xml
+++ b/netconf/mdsal-netconf-ssh/pom.xml
@@ -27,6 +27,11 @@
       <groupId>${project.groupId}</groupId>
       <artifactId>netconf-ssh</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.apache.aries.blueprint</groupId>
+      <artifactId>org.apache.aries.blueprint.core</artifactId>
+      <scope>provided</scope>
+    </dependency>
   </dependencies>
 
   <build>
diff --git a/netconf/mdsal-netconf-ssh/src/main/resources/org/opendaylight/blueprint/netconf-ssh.xml b/netconf/mdsal-netconf-ssh/src/main/resources/org/opendaylight/blueprint/netconf-ssh.xml
index 9d5d3ed409..1b1278edf6 100755
--- a/netconf/mdsal-netconf-ssh/src/main/resources/org/opendaylight/blueprint/netconf-ssh.xml
+++ b/netconf/mdsal-netconf-ssh/src/main/resources/org/opendaylight/blueprint/netconf-ssh.xml
@@ -13,9 +13,12 @@
 
     <reference id="netconfServerDispatcher" interface="org.opendaylight.netconf.api.NetconfServerDispatcher"/>
     <reference id="globalWorkerGroup" interface="io.netty.channel.EventLoopGroup" odl:type="global-worker-group"/>
-    <reference id="executor" interface="io.netty.util.concurrent.EventExecutor" odl:type="global-event-executor"/>
     <reference id="authProvider" interface="org.opendaylight.netconf.auth.AuthProvider" odl:type="netconf-auth-provider"/>
 
+    <reference id="executor" interface="io.netty.util.concurrent.EventExecutor" odl:type="global-event-executor">
+        <reference-listener ref="netconfMdsalServer" unbind-method="unbind"/>
+    </reference>
+
     <!--    NETCONF server for MD-SAL (listening by default on port 2830)-->
 
     <cm:property-placeholder persistent-id="org.opendaylight.netconf.ssh" update-strategy="none">
diff --git a/netconf/netconf-ssh/src/main/java/org/opendaylight/netconf/ssh/NetconfNorthboundSshServer.java b/netconf/netconf-ssh/src/main/java/org/opendaylight/netconf/ssh/NetconfNorthboundSshServer.java
index f478029323..fa5337c6c8 100644
--- a/netconf/netconf-ssh/src/main/java/org/opendaylight/netconf/ssh/NetconfNorthboundSshServer.java
+++ b/netconf/netconf-ssh/src/main/java/org/opendaylight/netconf/ssh/NetconfNorthboundSshServer.java
@@ -21,6 +21,7 @@ import org.opendaylight.netconf.auth.AuthProvider;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IetfInetUtil;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddressBuilder;
+import org.osgi.framework.ServiceReference;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -87,4 +88,18 @@ public class NetconfNorthboundSshServer {
             localServer.cancel(true);
         }
     }
+
+    /*
+     * Called when the underlying reference to EventExecutor is about to be removed from the container allowing
+     * us to close the ssh server while it still exists.
+     */
+    public void unbind(final ServiceReference<?> reference) {
+        LOG.debug("EventExecutor is being removed, closing netconf ssh server. {}", reference);
+
+        try {
+            close();
+        } catch (final IOException e) {
+            LOG.error("Closing of ssh server failed while unbinding reference listener.", e);
+        }
+    }
 }
-- 
2.36.6