refactor(capelin): Support flexible topology creation

This change adds support for creating flexible topologies by creating a
TopologyFactory interface that is responsible for configuring the hosts
of a compute service.

4 files changed, 139 insertions, 63 deletions

diff --git a/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/ComputeWorkloadRunner.kt b/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/ComputeWorkloadRunner.kt
index cc9f2705..29d84a9a 100644
--- a/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/ComputeWorkloadRunner.kt
+++ b/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/ComputeWorkloadRunner.kt
@@ -33,12 +33,9 @@ import kotlinx.coroutines.yield
 import org.opendc.compute.service.ComputeService
 import org.opendc.compute.service.scheduler.ComputeScheduler
 import org.opendc.compute.simulator.SimHost
-import org.opendc.compute.workload.env.MachineDef
+import org.opendc.compute.workload.topology.HostSpec
 import org.opendc.compute.workload.trace.TraceReader
-import org.opendc.simulator.compute.kernel.SimFairShareHypervisorProvider
-import org.opendc.simulator.compute.kernel.SimHypervisorProvider
 import org.opendc.simulator.compute.kernel.interference.VmInterferenceModel
-import org.opendc.simulator.compute.power.SimplePowerDriver
 import org.opendc.simulator.compute.workload.SimTraceWorkload
 import org.opendc.simulator.compute.workload.SimWorkload
 import org.opendc.simulator.resources.SimResourceInterpreter
@@ -50,15 +47,19 @@ import kotlin.math.max
 
 /**
  * Helper class to simulated VM-based workloads in OpenDC.
+ *
+ * @param context [CoroutineContext] to run the simulation in.
+ * @param clock [Clock] instance tracking simulation time.
+ * @param scheduler [ComputeScheduler] implementation to use for the service.
+ * @param failureModel A failure model to use for injecting failures.
+ * @param interferenceModel The model to use for performance interference.
  */
 public class ComputeWorkloadRunner(
     private val context: CoroutineContext,
     private val clock: Clock,
     scheduler: ComputeScheduler,
-    machines: List<MachineDef>,
     private val failureModel: FailureModel? = null,
-    interferenceModel: VmInterferenceModel? = null,
-    hypervisorProvider: SimHypervisorProvider = SimFairShareHypervisorProvider()
+    private val interferenceModel: VmInterferenceModel? = null,
 ) : AutoCloseable {
     /**
      * The [ComputeService] that has been configured by the manager.
@@ -86,13 +87,6 @@ public class ComputeWorkloadRunner(
         val (service, serviceMeterProvider) = createService(scheduler)
         this._metricProducers.add(serviceMeterProvider)
         this.service = service
-
-        for (def in machines) {
-            val (host, hostMeterProvider) = createHost(def, hypervisorProvider, interferenceModel)
-            this._metricProducers.add(hostMeterProvider)
-            hosts.add(host)
-            this.service.addHost(host)
-        }
     }
 
     /**
@@ -156,6 +150,46 @@ public class ComputeWorkloadRunner(
         }
     }
 
+    /**
+     * Register a host for this simulation.
+     *
+     * @param spec The definition of the host.
+     * @return The [SimHost] that has been constructed by the runner.
+     */
+    public fun registerHost(spec: HostSpec): SimHost {
+        val resource = Resource.builder()
+            .put(HOST_ID, spec.uid.toString())
+            .put(HOST_NAME, spec.name)
+            .put(HOST_ARCH, ResourceAttributes.HostArchValues.AMD64)
+            .put(HOST_NCPUS, spec.model.cpus.size)
+            .put(HOST_MEM_CAPACITY, spec.model.memory.sumOf { it.size })
+            .build()
+
+        val meterProvider = SdkMeterProvider.builder()
+            .setClock(clock.toOtelClock())
+            .setResource(resource)
+            .build()
+        _metricProducers.add(meterProvider)
+
+        val host = SimHost(
+            spec.uid,
+            spec.name,
+            spec.model,
+            spec.meta,
+            context,
+            interpreter,
+            meterProvider,
+            spec.hypervisor,
+            powerDriver = spec.powerDriver,
+            interferenceDomain = interferenceModel?.newDomain(),
+        )
+
+        hosts.add(host)
+        service.addHost(host)
+
+        return host
+    }
+
     override fun close() {
         service.close()
 
@@ -182,41 +216,4 @@ public class ComputeWorkloadRunner(
         val service = ComputeService(context, clock, meterProvider, scheduler)
         return service to meterProvider
     }
-
-    /**
-     * Construct a [SimHost] instance for the specified [MachineDef].
-     */
-    private fun createHost(
-        def: MachineDef,
-        hypervisorProvider: SimHypervisorProvider,
-        interferenceModel: VmInterferenceModel? = null
-    ): Pair<SimHost, SdkMeterProvider> {
-        val resource = Resource.builder()
-            .put(HOST_ID, def.uid.toString())
-            .put(HOST_NAME, def.name)
-            .put(HOST_ARCH, ResourceAttributes.HostArchValues.AMD64)
-            .put(HOST_NCPUS, def.model.cpus.size)
-            .put(HOST_MEM_CAPACITY, def.model.memory.sumOf { it.size })
-            .build()
-
-        val meterProvider = SdkMeterProvider.builder()
-            .setClock(clock.toOtelClock())
-            .setResource(resource)
-            .build()
-
-        val host = SimHost(
-            def.uid,
-            def.name,
-            def.model,
-            def.meta,
-            context,
-            interpreter,
-            meterProvider,
-            hypervisorProvider,
-            powerDriver = SimplePowerDriver(def.powerModel),
-            interferenceDomain = interferenceModel?.newDomain()
-        )
-
-        return host to meterProvider
-    }
 }
diff --git a/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/topology/HostSpec.kt b/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/topology/HostSpec.kt
new file mode 100644
index 00000000..f3dc1e9e
--- /dev/null
+++ b/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/topology/HostSpec.kt
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.compute.workload.topology
+
+import org.opendc.simulator.compute.kernel.SimFairShareHypervisorProvider
+import org.opendc.simulator.compute.kernel.SimHypervisorProvider
+import org.opendc.simulator.compute.model.MachineModel
+import org.opendc.simulator.compute.power.PowerDriver
+import java.util.*
+
+/**
+ * Description of a physical host that will be simulated by OpenDC and host the virtual machines.
+ *
+ * @param uid Unique identifier of the host.
+ * @param name The name of the host.
+ * @param meta The metadata of the host.
+ * @param model The physical model of the machine.
+ * @param powerDriver The [PowerDriver] to model the power consumption of the machine.
+ * @param hypervisor The hypervisor implementation to use.
+ */
+public data class HostSpec(
+    val uid: UUID,
+    val name: String,
+    val meta: Map<String, Any>,
+    val model: MachineModel,
+    val powerDriver: PowerDriver,
+    val hypervisor: SimHypervisorProvider = SimFairShareHypervisorProvider()
+)
diff --git a/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/topology/Topology.kt b/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/topology/Topology.kt
new file mode 100644
index 00000000..3b8dc918
--- /dev/null
+++ b/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/topology/Topology.kt
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.compute.workload.topology
+
+/**
+ * Representation of the environment of the compute service, describing the physical details of every host.
+ */
+public interface Topology {
+    /**
+     * Resolve the [Topology] into a list of [HostSpec]s.
+     */
+    public fun resolve(): List<HostSpec>
+}
diff --git a/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/env/MachineDef.kt b/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/topology/TopologyHelpers.kt
index c1695696..09159a93 100644
--- a/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/env/MachineDef.kt
+++ b/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/topology/TopologyHelpers.kt
@@ -20,19 +20,17 @@
  * SOFTWARE.
  */
 
-package org.opendc.compute.workload.env
+@file:JvmName("TopologyHelpers")
+package org.opendc.compute.workload.topology
 
-import org.opendc.simulator.compute.model.MachineModel
-import org.opendc.simulator.compute.power.PowerModel
-import java.util.*
+import org.opendc.compute.workload.ComputeWorkloadRunner
 
 /**
- * A definition of a machine in a cluster.
+ * Apply the specified [topology] to the given [ComputeWorkloadRunner].
  */
-public data class MachineDef(
-    val uid: UUID,
-    val name: String,
-    val meta: Map<String, Any>,
-    val model: MachineModel,
-    val powerModel: PowerModel
-)
+public fun ComputeWorkloadRunner.apply(topology: Topology) {
+    val hosts = topology.resolve()
+    for (spec in hosts) {
+        registerHost(spec)
+    }
+}