Clean up config for dns servers

server/lib/runMode.ts

@@ -0,0 +1,14 @@
+// Which entry point is running. Standalone entry points set this before
+// anything loads the config, so the config schema can skip requirements
+// that only apply to the full Pangolin server.
+export type RunMode = "server" | "dns";
+
+let runMode: RunMode = "server";
+
+export function setRunMode(mode: RunMode) {
+    runMode = mode;
+}
+
+export function getRunMode(): RunMode {
+    return runMode;
+}