feat: system optional capabilities

apps/server/src/core/capabilities.ts

@@ -0,0 +1,55 @@
+import * as fs from "node:fs/promises";
+import Docker from "dockerode";
+import { logger } from "../utils/logger";
+
+export type SystemCapabilities = {
+	docker: boolean;
+};
+
+let capabilitiesPromise: Promise<SystemCapabilities> | null = null;
+
+/**
+ * Returns the current system capabilities.
+ * On first call, detects all capabilities and caches the promise.
+ * Subsequent calls return the same cached promise, ensuring detection only happens once.
+ */
+export async function getCapabilities(): Promise<SystemCapabilities> {
+	if (capabilitiesPromise === null) {
+		// Start detection and cache the promise
+		capabilitiesPromise = detectCapabilities();
+	}
+
+	return capabilitiesPromise;
+}
+
+/**
+ * Detects which optional capabilities are available in the current environment
+ */
+async function detectCapabilities(): Promise<SystemCapabilities> {
+	return {
+		docker: await detectDocker(),
+	};
+}
+
+/**
+ * Checks if Docker is available by:
+ * 1. Checking if /var/run/docker.sock exists and is accessible
+ * 2. Attempting to ping the Docker daemon
+ */
+async function detectDocker(): Promise<boolean> {
+	try {
+		await fs.access("/var/run/docker.sock");
+
+		const docker = new Docker();
+		await docker.ping();
+
+		logger.info("Docker capability: enabled");
+		return true;
+	} catch (_) {
+		logger.warn(
+			"Docker capability: disabled. " +
+				"To enable: mount /var/run/docker.sock and /run/docker/plugins in docker-compose.yml",
+		);
+		return false;
+	}
+}