Add safe manual instance rebalancing

src/lib/server/provisioning/launch-worker.ts

@@ -2,7 +2,7 @@ import { parentPort } from 'node:worker_threads';
 import { posix } from 'node:path';
 import { db } from '../db/index.js';
 import { relDestForKind } from '../config.js';
-import { captureRecipe, summarizeRecipe } from '../fleet/launch-recipes.js';
+import { captureRecipe, recipeForDeployment, summarizeRecipe, type LaunchRecipe } from '../fleet/launch-recipes.js';
 import { sha256Buffer } from '../fleet/files.js';
 import type { NativeLaunchInput } from './launch-preparation.js';
 import { choosePlacement, type PlacementOptions } from '../hosts/capacity.js';
@@ -17,12 +17,26 @@ parentPort!.on('message', (message: { id: number; kind: 'launch'; input: NativeL
         }
         const input = message.input;
         // All file versions and composed configuration belong to one snapshot.
-        const recipe = db().transaction(() => ({ ...captureRecipe(input.game, input.mapSlug, input.rconPassword),
-            native: input.native, image: input.instance.image }))();
+        const { recipe, password } = db().transaction(() => {
+            if (!input.frozenRecipeId) return { recipe: { ...captureRecipe(input.game, input.mapSlug, input.rconPassword),
+                native: input.native, image: input.instance.image }, password: input.rconPassword };
+            const stored = recipeForDeployment(input.frozenRecipeId)?.recipe;
+            const migration = db().prepare('SELECT runtime_password FROM ec_host_migrations WHERE deployment_id=?')
+                .get(input.frozenRecipeId) as { runtime_password: string | null } | undefined;
+            if (!stored || !migration?.runtime_password || stored.files.some(file => file.content === undefined)) {
+                throw new Error('The preserved deployed recipe or runtime credentials are unavailable.');
+            }
+            for (const file of stored.files) {
+                const bytes = Buffer.from(file.content!, 'base64');
+                if (bytes.length !== file.size || sha256Buffer(bytes) !== file.sha256) throw new Error('Preserved deployed file verification failed.');
+            }
+            return { recipe: { ...stored, native: input.native, image: input.instance.image } as LaunchRecipe,
+                password: migration.runtime_password };
+        })();
         const instance = input.instance;
         const payload = {
             name: instance.server, game: recipe.game, libraryId: instance.library_id, image: instance.image,
-            port: instance.port, bindAddress: instance.bind_address, rconPassword: input.rconPassword,
+            port: instance.port, bindAddress: instance.bind_address, rconPassword: password,
             env: { PLUTAINER_SERVER_NAME: instance.server, PLUTAINER_PORT: String(instance.port),
                 PLUTAINER_GAME: recipe.game === 't6' ? 't6zm' : 't5sp', PLUTAINER_CONFIG_FILE: recipe.configFile,
                 PLUTAINER_MAP_ROTATE: 'false',