Add safe manual instance rebalancing

src/routes/api/deployments/[id]/cancel/+server.ts

@@ -1,9 +1,10 @@
 import { json } from '@sveltejs/kit';
-import { cancelProvisioningJob } from '$lib/server/provisioning/cancellation.js';
+import { cancelProvisioningJob, rebalanceCancellationBlocker } from '$lib/server/provisioning/cancellation.js';
 import { kickProvisioning } from '$lib/server/pipeline/worker.js';
 
 export function POST({ params }: { params: { id: string } }) {
-    if (!cancelProvisioningJob(params.id)) return json({ error: 'This operation can no longer be cancelled. Refresh to see its current state.' }, { status: 409 });
+    if (!cancelProvisioningJob(params.id)) return json({ error: rebalanceCancellationBlocker(params.id)
+        ?? 'This operation can no longer be cancelled. Refresh to see its current state.' }, { status: 409 });
     void kickProvisioning();
     return json({ ok: true });
 }

src/routes/api/rebalancing/+server.ts

@@ -0,0 +1,14 @@
+import { json } from '@sveltejs/kit';
+import { RebalanceError, previewRebalance, rebalanceReport, startRebalance, stopRebalance } from '$lib/server/rebalancing/index.js';
+
+export function GET() { return json(rebalanceReport()); }
+export async function POST({ request }: { request: Request }) {
+    try {
+        const body = await request.json();
+        if (!body || typeof body !== 'object' || Array.isArray(body)) throw new RebalanceError('Provide a rebalance action.');
+        if (body.action === 'preview') return json({ preview: previewRebalance(body.settings) });
+        if (body.action === 'start' && typeof body.previewId === 'string' && body.previewId.length <= 100) return json({ run: startRebalance(body.previewId) });
+        if (body.action === 'stop' && typeof body.id === 'string' && body.id.length <= 100) return json({ run: stopRebalance(body.id) });
+        throw new RebalanceError('Choose a supported rebalance action.');
+    } catch (error) { return json({ error: (error as Error).message }, { status: error instanceof RebalanceError ? error.status : 400 }); }
+}