Migrate instances when draining and verify hosts before enabling

src/lib/server/hosts/availability.ts

@@ -52,7 +52,9 @@ function observeHost(host: Host): HostAvailability {
         JOIN native_provisioning n ON n.instance_id=i.id JOIN server_deployments d ON d.id=n.deployment_id
         WHERE i.host_id=? AND i.retired_at IS NULL AND d.action IN ('create','rebuild')
         AND d.state IN ('running','awaiting-health')`).all(host.id) as { id: string; generation: number }[];
-    const unmeasured = pending.filter(instance => measured.get(instance.id) !== instance.generation).length;
+    const incoming = handle.prepare(`SELECT COUNT(*) AS n FROM ec_host_migrations m JOIN server_deployments d ON d.id=m.deployment_id
+        WHERE m.target_host_id=? AND (m.removed_at IS NULL OR d.state IN ('queued','waiting','interrupted'))`).get(host.id) as { n: number };
+    const unmeasured = pending.filter(instance => measured.get(instance.id) !== instance.generation).length + incoming.n;
     const { cpuCount, cpuUsagePercent, memoryTotal, memoryAvailable } = host.inventory;
     const freeCpu = cpuCount && cpuUsagePercent !== undefined
         ? Math.max(0, cpuCount * (0.95 - cpuUsagePercent / 100) - unmeasured * startup.cpuCores) : null;