Refactor P4Runtime subsystem to implement async connection procedure
This patch is an attempt to solve issues observed when restarting both
switches and ONOS nodes. Most of the issues seemed to depend on a
brittle mastership handling when deploying the pipeline.
With this patch, GDP registers devices to the core with available=false
(i.e. offline) and marks them online only when the P4 pipeline has been
deployed to the device. A new PiPipeconfWatchdogService takes care of
deploying pipelines and producing event when devices are ready.
Moreover, we fix a race condition where pipeconf-related behaviors
were not found. This was caused by GDP enforcing the merged
driver name in the network config, while external entities (e.g.
Mininet) were pushing a JSON blob with the base driver name. This patch
removes the need to rely on such a trick and instead uses
pipeconf-aware logic directly in the driver manager (change #19622).
Finally, we fix issues in P4RuntimeClientImpl that were causing the
stream channel not detecting unreachable devices. The solution is to
follow gRPC APIs and re-instantiate a new channel once the first fails.
Change-Id: I6fbc91859c0fb58a6db3bc197b7081a8fe9f97f7
diff --git a/core/api/src/main/java/org/onosproject/net/pi/service/PiPipeconfWatchdogService.java b/core/api/src/main/java/org/onosproject/net/pi/service/PiPipeconfWatchdogService.java
new file mode 100644
index 0000000..9462569
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/pi/service/PiPipeconfWatchdogService.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.net.pi.service;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.event.ListenerService;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.pi.model.PiPipeconfId;
+
+/**
+ * Service that periodically probes pipeline programmable devices, to check that
+ * their pipeline is configured with the expected pipeconf. It emits events
+ * about pipeline status changes.
+ */
+@Beta
+public interface PiPipeconfWatchdogService
+ extends ListenerService<PiPipeconfWatchdogEvent, PiPipeconfWatchdogListener> {
+
+ /**
+ * Status of a device pipeline.
+ */
+ enum PipelineStatus {
+ /**
+ * The device pipeline is ready to process packets.
+ */
+ READY,
+ /**
+ * The status is unknown and the device might not be able to process
+ * packets yet.
+ */
+ UNKNOWN,
+ }
+
+ /**
+ * Asynchronously triggers a probe task that checks the device pipeline
+ * status and, if required, configures it with the pipeconf associated to
+ * this device (via {@link PiPipeconfService#bindToDevice(PiPipeconfId,
+ * DeviceId)}).
+ *
+ * @param deviceId device to probe
+ */
+ void triggerProbe(DeviceId deviceId);
+
+ /**
+ * Returns the last known pipeline status of the given device.
+ *
+ * @param deviceId device ID
+ * @return pipeline status
+ */
+ PipelineStatus getStatus(DeviceId deviceId);
+}