restart apps on addon container change

when the IP changes on addon container re-create, the apps don't
detect this (maybe there is some large DNS cache timeout in docker)

src/apps.js

@@ -58,6 +58,7 @@ exports = module.exports = {
     restoreInstalledApps: restoreInstalledApps,
     configureInstalledApps: configureInstalledApps,
     schedulePendingTasks: schedulePendingTasks,
+    restartAppsUsingAddons: restartAppsUsingAddons,
 
     getDataDir: getDataDir,
     getIconPath: getIconPath,
@@ -1986,6 +1987,34 @@ function configureInstalledApps(callback) {
     });
 }
 
+function restartAppsUsingAddons(changedAddons, callback) {
+    assert(Array.isArray(changedAddons));
+    assert.strictEqual(typeof callback, 'function');
+
+    getAll(function (error, apps) {
+        if (error) return callback(error);
+
+        apps = apps.filter(app => app.manifest.addons && _.intersection(Object.keys(app.manifest.addons), changedAddons).length !== 0);
+        apps = apps.filter(app => app.installationState !== exports.ISTATE_ERROR); // remove errored apps. let them be 'repaired' by hand
+        apps = apps.filter(app => app.installationState !== exports.ISTATE_PENDING_RESTART); // safeguard against tasks being created non-stop restart if we crash on startup
+
+        async.eachSeries(apps, function (app, iteratorDone) {
+            debug(`restartAppsUsingAddons: marking ${app.fqdn} for restart`);
+
+            const task = {
+                args: {},
+                values: { runState: exports.RSTATE_RUNNING }
+            };
+            addTask(app.id, exports.ISTATE_PENDING_RESTART, task, function (error, result) {
+                if (error) debug(`restartAppsUsingAddons: error marking ${app.fqdn} for restart: ${JSON.stringify(error)}`);
+                else debug(`restartAppsUsingAddons: marked ${app.id} for restart with taskId ${result.taskId}`);
+
+                iteratorDone(); // ignore error
+            });
+        }, callback);
+    });
+}
+
 // auto-restart app tasks after a crash
 function schedulePendingTasks(callback) {
     assert.strictEqual(typeof callback, 'function');