Standalone dns server

Dockerfile.dns

@@ -0,0 +1,71 @@
+# Standalone image that runs only the authoritative DNS server
+# (server/private/dnsServer.ts) against an existing Pangolin database.
+#
+# Build:  docker build -f Dockerfile.dns -t pangolin-dns .
+# Run:    docker run -v ./config:/app/config -p 53:53/udp pangolin-dns
+#
+# The mounted config directory needs the same config.yml (database
+# connection) and privateConfig.yml (dns section with
+# enabled: true) as the Pangolin server whose database it reads.
+
+# Mirror of docker.io/library/node, kept in sync by
+# .github/workflows/mirror-node.yml (avoids Docker Hub / ECR pull rate limits)
+ARG NODE_IMAGE=ghcr.io/fosrl/node:24.22.1-slim
+
+FROM ${NODE_IMAGE} AS builder
+
+WORKDIR /app
+
+RUN apt-get update && apt-get install -y python3 make g++ && rm -rf /var/lib/apt/lists/*
+
+COPY package*.json .npmrc ./
+
+RUN npm ci
+
+COPY . .
+
+# The DNS server is private code, so only saas/enterprise builds include it
+ARG BUILD=enterprise
+ARG DATABASE=pg
+
+RUN npm run set:$DATABASE && \
+    npm run set:$BUILD && \
+    mkdir -p dist && \
+    node esbuild.mjs -e server/private/dnsServer.ts -o dist/dns.mjs && \
+    test -f dist/dns.mjs
+
+# Copy only the node_modules files the bundle can load
+RUN npm prune --omit=dev && \
+    node trace-deps.mjs -o /out dist/dns.mjs
+
+FROM ${NODE_IMAGE} AS runner
+
+WORKDIR /app
+
+RUN apt-get update && apt-get install -y tzdata && rm -rf /var/lib/apt/lists/*
+
+COPY --from=builder /out ./
+COPY --from=builder /app/dist/dns.mjs ./dist/dns.mjs
+COPY --from=builder /app/package.json ./package.json
+
+ENV ENVIRONMENT=prod
+ENV NODE_ENV=production
+
+EXPOSE 53/udp
+
+ARG VERSION="dev"
+ARG REVISION=""
+ARG CREATED=""
+
+LABEL org.opencontainers.image.source="https://github.com/fosrl/pangolin" \
+      org.opencontainers.image.url="https://github.com/fosrl/pangolin" \
+      org.opencontainers.image.documentation="https://docs.pangolin.net" \
+      org.opencontainers.image.vendor="Fossorial" \
+      org.opencontainers.image.licenses="Fossorial Commercial License" \
+      org.opencontainers.image.title="Pangolin DNS" \
+      org.opencontainers.image.description="Standalone Pangolin authoritative DNS server" \
+      org.opencontainers.image.version="${VERSION}" \
+      org.opencontainers.image.revision="${REVISION}" \
+      org.opencontainers.image.created="${CREATED}"
+
+CMD ["node", "--disable-warning=ExperimentalWarning", "--enable-source-maps", "dist/dns.mjs"]

server/private/dns.ts

@@ -16,13 +16,15 @@ import { privateConfig } from "#private/lib/config";
 
 let dnsServer: AuthoritativeDNSServer | undefined;
 
-export async function startDnsServer() {
+export async function startDnsServer(
+    options: { requireLicense?: boolean } = {}
+) {
     const dnsConfig = privateConfig.getRawPrivateConfig().dns;
     if (!dnsConfig || !dnsConfig.enabled) {
         return;
     }
 
-    dnsServer = new AuthoritativeDNSServer(dnsConfig.listen_port);
+    dnsServer = new AuthoritativeDNSServer(dnsConfig.listen_port, options);
 
     await dnsServer.start();
 }

server/private/dnsServer.ts

@@ -0,0 +1,53 @@
+/*
+ * This file is part of a proprietary work.
+ *
+ * Copyright (c) 2025-2026 Fossorial, Inc.
+ * All rights reserved.
+ *
+ * This file is licensed under the Fossorial Commercial License.
+ * You may not use this file except in compliance with the License.
+ * Unauthorized use, copying, modification, or distribution is strictly prohibited.
+ *
+ * This file is not licensed under the AGPLv3.
+ */
+
+// Standalone entry point that runs only the authoritative DNS server against
+// an existing Pangolin database, without the API, dashboard or schedulers.
+// Migrations are left to the main Pangolin server that owns the database.
+import "@server/extendZod";
+
+import logger from "@server/logger";
+import { privateConfig } from "#private/lib/config";
+import { rateLimitService } from "#private/lib/rateLimit";
+import { startDnsServer, stopDnsServer } from "./dns";
+
+async function start() {
+    if (!privateConfig.getRawPrivateConfig().dns?.enabled) {
+        throw new Error(
+            "DNS server is not enabled - set dns.enabled: true in the private config"
+        );
+    }
+
+    await startDnsServer({ requireLicense: false });
+
+    let stopping = false;
+    const shutdown = async () => {
+        if (stopping) return;
+        stopping = true;
+        try {
+            await stopDnsServer();
+            await rateLimitService.cleanup();
+        } catch (error) {
+            logger.error("Error during DNS server shutdown:", error);
+        }
+        process.exit(0);
+    };
+
+    process.on("SIGTERM", shutdown);
+    process.on("SIGINT", shutdown);
+}
+
+start().catch((error) => {
+    logger.error("Failed to start DNS server:", error);
+    process.exit(1);
+});

server/private/lib/dns/server.ts

@@ -36,7 +36,7 @@ import {
 import { privateConfig as config } from "#private/lib/config";
 import * as dnsResolver from "dns";
 import logger from "@server/logger";
-import { listExitNodes } from "../exitNodes";
+import { listExitNodesAcrossRegions } from "../exitNodes/exitNodes";
 import { parseCustomDnsRecordValues } from "@server/routers/customDnsRecord/types";
 import {
     matchCustomRecords,
@@ -44,7 +44,6 @@ import {
     type CustomZoneRecord
 } from "./customRecordMatch";
 import { rateLimitService } from "../rateLimit";
-import license from "#private/license/license";
 
 type DNSRecord = {
     id: number;
@@ -89,6 +88,7 @@ export class AuthoritativeDNSServer {
     // set refresh and read from memory here.
     private isLicensed: boolean = false;
     private licenseRefreshInterval: NodeJS.Timeout | null = null;
+    private requireLicense: boolean;
 
     // Cache for per-queryName zone resolution and SOA records
     private authoritativeDomainCache: LocalCache = createLocalCache(
@@ -100,8 +100,9 @@ export class AuthoritativeDNSServer {
         DNS_CACHE_TTL_SECONDS
     );
 
-    constructor(port: number) {
+    constructor(port: number, options: { requireLicense?: boolean } = {}) {
         this.port = port;
+        this.requireLicense = options.requireLicense ?? true;
         this.server = dgram.createSocket("udp4");
 
         this.setupServer();
@@ -965,7 +966,7 @@ export class AuthoritativeDNSServer {
         queryType: dns.RecordType
     ): Promise<DNSRecord[] | null> {
         // TODO: EVENTUALLY WE SHOULD PICK THE CLOSEST EXIT NODE TO THE USER BASED ON LATENCY
-        const exitNodesList = await listExitNodes(orgId, true);
+        const exitNodesList = await listExitNodesAcrossRegions(orgId, true);
 
         if (!exitNodesList || exitNodesList.length === 0) {
             logger.warn(`No exit nodes found for orgId: ${orgId}`);
@@ -1549,6 +1550,12 @@ export class AuthoritativeDNSServer {
 
     private async refreshLicenseStatus(): Promise<void> {
         try {
+            // Imported lazily so the standalone DNS server, which runs
+            // without a license, never loads the license module (it touches
+            // the database and starts phoning home as soon as it is imported)
+            const { default: license } = await import(
+                "#private/license/license"
+            );
             this.isLicensed = await license.hasTier([
                 "personal",
                 "tier2",
@@ -1568,10 +1575,14 @@ export class AuthoritativeDNSServer {
             );
         }, 60_000);
 
-        await this.refreshLicenseStatus();
-        this.licenseRefreshInterval = setInterval(() => {
-            this.refreshLicenseStatus();
-        }, 60_000);
+        if (this.requireLicense) {
+            await this.refreshLicenseStatus();
+            this.licenseRefreshInterval = setInterval(() => {
+                this.refreshLicenseStatus();
+            }, 60_000);
+        } else {
+            this.isLicensed = true;
+        }
 
         return new Promise((resolve, reject) => {
             this.server.bind(this.port, (err?: Error) => {

server/private/lib/exitNodes/exitNodes.ts

@@ -333,6 +333,52 @@ export async function listExitNodes(
     return exitNodesList;
 }
 
+// Like listExitNodes, but gerbil nodes are not restricted to this server's
+// region, so a caller that prefers same-region nodes (e.g. the DNS server)
+// can still fall back to another region when this one has none online.
+export async function listExitNodesAcrossRegions(
+    orgId: string,
+    filterOnline = false
+) {
+    const allExitNodes = await db
+        .select({
+            exitNodeId: exitNodes.exitNodeId,
+            endpoint: exitNodes.endpoint,
+            online: exitNodes.online,
+            type: exitNodes.type,
+            region: exitNodes.region
+        })
+        .from(exitNodes)
+        .leftJoin(
+            exitNodeOrgs,
+            eq(exitNodes.exitNodeId, exitNodeOrgs.exitNodeId)
+        )
+        .where(
+            or(
+                eq(exitNodes.type, "gerbil"),
+                and(
+                    eq(exitNodes.type, "remoteExitNode"),
+                    eq(exitNodeOrgs.orgId, orgId)
+                )
+            )
+        );
+
+    const onlineNodes = allExitNodes.filter(
+        (node) => !filterOnline || node.online
+    );
+    const remoteExitNodesList = onlineNodes.filter(
+        (node) => node.type === "remoteExitNode"
+    );
+    const gerbilExitNodes = onlineNodes.filter(
+        (node) => node.type === "gerbil"
+    );
+
+    // An org's own remote exit nodes take precedence over the cloud ones
+    return remoteExitNodesList.length > 0
+        ? remoteExitNodesList
+        : gerbilExitNodes;
+}
+
 export type ExitNodePingResult = {
     exitNodeId: number;
     latencyMs: number;