Add status events for create/delete instance

Notify plugins of status changes when instances are created and deleted.

packages/lib/plugin.js

@@ -252,15 +252,18 @@ class BaseMasterPlugin {
 	/**
 	 * Called when the status of an instance changes
 	 *
-	 * Invoked when the master server has received notice from a slave that
-	 * the running status of an instance has changed.  The possible statuses
-	 * that can be notified about are:
-	 * - `stopped`: Instance is no longer running.
+	 * Invoked when the master server has changed the status of an instance
+	 * or received notice from a slave that the status of an instance has
+	 * changed.  The possible statuses that can be notified about are:
+	 * - `unassigned:`: Instance is no longer asssigned to a slave.
+	 * - `stopped`: Instance is no longer running or was just assigned to a
+	 *   slave.
 	 * - `starting`: Instance is in the process of starting up.
 	 * - `running`: Instance startup completed and is now running.
 	 * - `creating_save`: Instance is in the process of creating a save.
 	 * - `exporting_data`: Instance is in the process of exporting item
 	 *   icons and locale data.
+	 * - `deleted`: Instance was deleted.
 	 *
 	 * On master startup all known instances gets the status `unknown` if
 	 * they are assigned to a slave, when the slave then connects to the
@@ -268,12 +271,17 @@ class BaseMasterPlugin {
 	 * is invoked for all those instances.  You can detect this situation by
 	 * checking if prev equals `unknown`.
 	 *
+	 * When instances are created on the master they will notify of a status
+	 * change with prev set to null.  While the status of new instances is
+	 * in most cases `unassigned` it's possible for the created instance to
+	 * start with any state in some slave connection corner cases.
+	 *
 	 * Note that it's possible for status change notification to get lost in
 	 * the case of network outages if reconnect fails to re-establish the
 	 * session between the master server and the slave.
 	 *
 	 * @param {Object} instance - the instance that changed.
-	 * @param {string} prev - the previous status of the instance.
+	 * @param {?string} prev - the previous status of the instance.
 	 */
 	async onInstanceStatusChanged(instance, prev) { }
 

packages/master/src/ControlConnection.js

@@ -8,6 +8,7 @@ const libErrors = require("@clusterio/lib/errors");
 const libLink = require("@clusterio/lib/link");
 const { logger } = require("@clusterio/lib/logging");
 const libLoggingUtils = require("@clusterio/lib/logging_utils");
+const libPlugin = require("@clusterio/lib/plugin");
 const libPrometheus = require("@clusterio/lib/prometheus");
 const libUsers = require("@clusterio/lib/users");
 
@@ -170,7 +171,9 @@ class ControlConnection extends BaseConnection {
 		};
 		instanceConfig.set("factorio.settings", settings);
 
-		this._master.instances.set(instanceId, { config: instanceConfig, status: "unassigned" });
+		let instance = { config: instanceConfig, status: "unassigned" };
+		this._master.instances.set(instanceId, instance);
+		await libPlugin.invokeHook(this._master.plugins, "onInstanceStatusChanged", instance, null);
 	}
 
 	async deleteInstanceRequestHandler(message, request) {
@@ -183,6 +186,10 @@ class ControlConnection extends BaseConnection {
 			await this.forwardRequestToInstance(message, request);
 		}
 		this._master.instances.delete(message.data.instance_id);
+
+		let prev = instance.status;
+		instance.status = "deleted";
+		await libPlugin.invokeHook(this._master.plugins, "onInstanceStatusChanged", instance, prev);
 	}
 
 	async getInstanceConfigRequestHandler(message) {

packages/master/src/SlaveConnection.js

@@ -71,9 +71,9 @@ class SlaveConnection extends BaseConnection {
 		}
 
 		// Assign instances the slave has but master does not
-		for (let instance of message.data.instances) {
+		for (let instanceData of message.data.instances) {
 			let instanceConfig = new libConfig.InstanceConfig("master");
-			await instanceConfig.load(instance.serialized_config, "slave");
+			await instanceConfig.load(instanceData.serialized_config, "slave");
 
 			let masterInstance = this._master.instances.get(instanceConfig.get("instance.id"));
 			if (masterInstance) {
@@ -86,24 +86,23 @@ class SlaveConnection extends BaseConnection {
 				}
 
 				// Already have this instance, update state instead
-				if (masterInstance.status !== instance.status) {
+				if (masterInstance.status !== instanceData.status) {
 					let prev = masterInstance.status;
-					masterInstance.status = instance.status;
-					logger.verbose(`Instance ${instanceConfig.get("instance.name")} State: ${instance.status}`);
-					await libPlugin.invokeHook(this._master.plugins, "onInstanceStatusChanged", instance, prev);
+					masterInstance.status = instanceData.status;
+					logger.verbose(`Instance ${instanceConfig.get("instance.name")} State: ${instanceData.status}`);
+					await libPlugin.invokeHook(this._master.plugins, "onInstanceStatusChanged", masterInstance, prev);
 				}
 				continue;
 			}
 
 			instanceConfig.set("instance.assigned_slave", this._id);
-			this._master.instances.set(instanceConfig.get("instance.id"), {
-				config: instanceConfig,
-				status: instance.status,
-			});
+			let newInstance = { config: instanceConfig, status: instanceData.status };
+			this._master.instances.set(instanceConfig.get("instance.id"), newInstance);
 			await libLink.messages.assignInstance.send(this, {
 				instance_id: instanceConfig.get("instance.id"),
 				serialized_config: instanceConfig.serialize("slave"),
 			});
+			await libPlugin.invokeHook(this._master.plugins, "onInstanceStatusChanged", newInstance, null);
 		}
 
 		// Push lists to make sure they are in sync.