[SDFAB-359] Purge all on device disconnection

The previous logic was relying on the purgeOnDisconnection device configuration.
However, we want to allow flow rules to stay in the store when a device disconnects if those are
created by a different application. For this reason, we purge flow rule and groups explicitly on
device disconnection in SR by specifying the SR app ID.

Change-Id: I59369a1a18b82f134aaaab37be49e2ac746a4e9f
diff --git a/impl/src/main/java/org/onosproject/segmentrouting/DeviceConfiguration.java b/impl/src/main/java/org/onosproject/segmentrouting/DeviceConfiguration.java
index 7980d25..3db48ab 100644
--- a/impl/src/main/java/org/onosproject/segmentrouting/DeviceConfiguration.java
+++ b/impl/src/main/java/org/onosproject/segmentrouting/DeviceConfiguration.java
@@ -36,7 +36,6 @@
 import org.onosproject.net.HostId;
 import org.onosproject.net.PortNumber;
 import org.onosproject.net.config.ConfigException;
-import org.onosproject.net.config.basics.BasicDeviceConfig;
 import org.onosproject.net.config.basics.BasicHostConfig;
 import org.onosproject.net.config.basics.InterfaceConfig;
 import org.onosproject.net.host.InterfaceIpAddress;
@@ -117,14 +116,6 @@
         Set<DeviceId> deviceSubjects =
                 srManager.cfgService.getSubjects(DeviceId.class, SegmentRoutingDeviceConfig.class);
         deviceSubjects.forEach(subject -> {
-            BasicDeviceConfig basicDeviceConfig = srManager.cfgService.addConfig(subject, BasicDeviceConfig.class);
-            if (!basicDeviceConfig.purgeOnDisconnection()) {
-                // Setting purge on disconnection flag for the device SR has control over.
-                // addConfig returns a config if it exists or creates a new one.
-                log.info("PurgeOnDisconnection set to true for device {}", subject);
-                basicDeviceConfig.purgeOnDisconnection(true);
-                srManager.cfgService.applyConfig(subject, BasicDeviceConfig.class, basicDeviceConfig.node());
-            }
             SegmentRoutingDeviceConfig config =
                     srManager.cfgService.getConfig(subject, SegmentRoutingDeviceConfig.class);
             SegmentRouterInfo info = new SegmentRouterInfo();
diff --git a/impl/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java b/impl/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
index c42773f..b12b229 100644
--- a/impl/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
+++ b/impl/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
@@ -1689,6 +1689,12 @@
             .forEach(entry -> entry.getValue().cleanUpForNeighborDown(device.id()));
 
         phasedRecoveryService.reset(device.id());
+
+        // Trigger purgeAll only on devices managed by SR, other devices rely on
+        // the purgeOnDisconnection device property.
+        if (deviceConfiguration.isConfigured(device.id())) {
+            flowObjectiveService.purgeAll(device.id(), appId);
+        }
     }
 
     /**