compute: Improvements to cloud compute model (v1)

This is the first of the pull requests in an attempt to improve the existing cloud compute model (see #86). This pull request restructures the compute API and splits the consumer and service interfaces into different modules:

- opendc-compute-api now defines the API interface for the OpenDC Compute module, which can be used by consumers of the OpenDC Compute service.
- opendc-compute-service hosts the service implementation for OpenDC Compute and contains all business logic regarding the IaaS platform (such as scheduling).
- opendc-compute-simulator implements a "compute driver" for the OpenDC Compute platform that simulates submitted workloads.
- Image is now a data-class and does not specify itself the workload to simulate. Instead, the workload should be passed via its tags currently (with key "workload"). In the future, the simulation backend will accept a mapper interface that maps Images to Workloads.

8 files changed, 378 insertions, 0 deletions

diff --git a/simulator/opendc-compute/opendc-compute-api/build.gradle.kts b/simulator/opendc-compute/opendc-compute-api/build.gradle.kts
new file mode 100644
index 00000000..10046322
--- /dev/null
+++ b/simulator/opendc-compute/opendc-compute-api/build.gradle.kts
@@ -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.
+ */
+
+description = "API interface for the OpenDC Compute service"
+
+/* Build configuration */
+plugins {
+    `kotlin-library-conventions`
+}
+
+dependencies {
+    api(platform(project(":opendc-platform")))
+    api(project(":opendc-core"))
+}
diff --git a/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ComputeClient.kt b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ComputeClient.kt
new file mode 100644
index 00000000..025513e6
--- /dev/null
+++ b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ComputeClient.kt
@@ -0,0 +1,46 @@
+/*
+ * 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.api
+
+/**
+ * A client interface for the OpenDC Compute service.
+ */
+public interface ComputeClient : AutoCloseable {
+    /**
+     * Create a new [Server] instance at this compute service.
+     *
+     * @param name The name of the server to deploy.
+     * @param image The image to be deployed.
+     * @param flavor The flavor of the machine instance to run this [image] on.
+     */
+    public suspend fun newServer(
+        name: String,
+        image: Image,
+        flavor: Flavor
+    ): Server
+
+    /**
+     * Release the resources associated with this client, preventing any further API calls.
+     */
+    public override fun close()
+}
diff --git a/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ComputeWorkload.kt b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ComputeWorkload.kt
new file mode 100644
index 00000000..64a47277
--- /dev/null
+++ b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ComputeWorkload.kt
@@ -0,0 +1,46 @@
+/*
+ * 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.api
+
+import org.opendc.core.User
+import org.opendc.core.workload.Workload
+import java.util.UUID
+
+/**
+ * A workload that represents a VM.
+ *
+ * @property uid A unique identified of this VM.
+ * @property name The name of this VM.
+ * @property owner The owner of the VM.
+ * @property image The image of the VM.
+ */
+public data class ComputeWorkload(
+    override val uid: UUID,
+    override val name: String,
+    override val owner: User,
+    val image: Image
+) : Workload {
+    override fun equals(other: Any?): Boolean = other is ComputeWorkload && uid == other.uid
+
+    override fun hashCode(): Int = uid.hashCode()
+}
diff --git a/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/Flavor.kt b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/Flavor.kt
new file mode 100644
index 00000000..bf5f0ce4
--- /dev/null
+++ b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/Flavor.kt
@@ -0,0 +1,39 @@
+/*
+ * 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.api
+
+/**
+ * Flavors define the compute and memory capacity of [Server] instance. To put it simply, a flavor is an available
+ * hardware configuration for a server. It defines the size of a virtual server that can be launched.
+ */
+public data class Flavor(
+    /**
+     * The number of (virtual) processing cores to use.
+     */
+    public val cpuCount: Int,
+
+    /**
+     * The amount of RAM available to the server (in MB).
+     */
+    public val memorySize: Long
+)
diff --git a/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/Image.kt b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/Image.kt
new file mode 100644
index 00000000..280c4d89
--- /dev/null
+++ b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/Image.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.api
+
+import org.opendc.core.resource.Resource
+import org.opendc.core.resource.TagContainer
+import java.util.*
+
+/**
+ * An image containing a bootable operating system that can directly be executed by physical or virtual server.
+ *
+ * OpenStack: A collection of files used to create or rebuild a server. Operators provide a number of pre-built OS
+ * images by default. You may also create custom images from cloud servers you have launched. These custom images are
+ * useful for backup purposes or for producing “gold” server images if you plan to deploy a particular server
+ * configuration frequently.
+ */
+public data class Image(
+    public override val uid: UUID,
+    public override val name: String,
+    public override val tags: TagContainer
+) : Resource {
+    public companion object {
+        /**
+         * An empty boot disk [Image] that exits immediately on start.
+         */
+        public val EMPTY: Image = Image(UUID.randomUUID(), "empty", emptyMap())
+    }
+}
diff --git a/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/Server.kt b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/Server.kt
new file mode 100644
index 00000000..ab1eb860
--- /dev/null
+++ b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/Server.kt
@@ -0,0 +1,74 @@
+/*
+ * 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.api
+
+import org.opendc.core.resource.Resource
+
+/**
+ * A stateful object representing a server instance that is running on some physical or virtual machine.
+ */
+public interface Server : Resource {
+    /**
+     * The name of the server.
+     */
+    public override val name: String
+
+    /**
+     * The flavor of the server.
+     */
+    public val flavor: Flavor
+
+    /**
+     * The image of the server.
+     */
+    public val image: Image
+
+    /**
+     * The tags assigned to the server.
+     */
+    public override val tags: Map<String, String>
+
+    /**
+     * The last known state of the server.
+     */
+    public val state: ServerState
+
+    /**
+     * Register the specified [ServerWatcher] to watch the state of the server.
+     *
+     * @param watcher The watcher to register for the server.
+     */
+    public fun watch(watcher: ServerWatcher)
+
+    /**
+     * De-register the specified [ServerWatcher] from the server to stop it from receiving events.
+     *
+     * @param watcher The watcher to de-register from the server.
+     */
+    public fun unwatch(watcher: ServerWatcher)
+
+    /**
+     * Refresh the local state of the resource.
+     */
+    public suspend fun refresh()
+}
diff --git a/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ServerState.kt b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ServerState.kt
new file mode 100644
index 00000000..25d2e519
--- /dev/null
+++ b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ServerState.kt
@@ -0,0 +1,53 @@
+/*
+ * 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.api
+
+/**
+ * An enumeration describing the possible states of a server.
+ */
+public enum class ServerState {
+    /**
+     * The server has not yet finished the original build process.
+     */
+    BUILD,
+
+    /**
+     * The server was powered down by the user.
+     */
+    SHUTOFF,
+
+    /**
+     * The server is active and running.
+     */
+    ACTIVE,
+
+    /**
+     * The server is in error.
+     */
+    ERROR,
+
+    /**
+     * The state of the server is unknown.
+     */
+    UNKNOWN,
+}
diff --git a/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ServerWatcher.kt b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ServerWatcher.kt
new file mode 100644
index 00000000..48a17b30
--- /dev/null
+++ b/simulator/opendc-compute/opendc-compute-api/src/main/kotlin/org/opendc/compute/api/ServerWatcher.kt
@@ -0,0 +1,39 @@
+/*
+ * 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.api
+
+/**
+ * An interface used to watch the state of [Server] instances.
+ */
+public interface ServerWatcher {
+    /**
+     * This method is invoked when the state of a [Server] changes.
+     *
+     * Note that the state of [server] might not reflect the state as reported by the invocation, as a call to
+     * [Server.refresh] is required to update its state.
+     *
+     * @param server The server whose state has changed.
+     * @param newState The new state of the server.
+     */
+    public fun onStateChanged(server: Server, newState: ServerState) {}
+}