add support for containers in wrangler multiworker dev (#10032)

---------

Co-authored-by: emily-shen <[email protected]>

Author: dario-piotrowicz

.changeset/late-taxis-switch.md

@@ -0,0 +1,7 @@
+---
+"wrangler": patch
+---
+
+add support for containers in wrangler multiworker dev
+
+currently when running `wrangler dev` with different workers (meaning that the `-c|--config` flag is used multiple times) containers are not being included, meaning that trying to interact with them at runtime would not work and cause errors instead. The changes here address the above making wrangler correctly detect and wire up the containers.

fixtures/interactive-dev-tests/multi-containers-app/src/index.ts

@@ -16,7 +16,7 @@ class FixtureTestContainerBase extends DurableObject<Env> {
 			});
 			// On the first request we simply start the container and return,
 			// on the following requests the container can actually be accessed.
-			// Note that we do this this way becase container.start is not awaitable
+			// Note that we do this this way because container.start is not awaitable
 			// meaning that we can't simply wait here for the container to be ready
 			return new Response("Container started");
 		}

fixtures/interactive-dev-tests/multi-workers-containers-app/tsconfig.json

@@ -0,0 +1,13 @@
+{
+	"compilerOptions": {
+		"target": "ES2020",
+		"module": "ESNext",
+		"lib": ["ES2020"],
+		"types": ["@cloudflare/workers-types"],
+		"moduleResolution": "node",
+		"noEmit": true,
+		"skipLibCheck": true
+	},
+	"include": ["**/*.ts"],
+	"exclude": ["tests"]
+}

fixtures/interactive-dev-tests/multi-workers-containers-app/workerA/Dockerfile

@@ -0,0 +1,18 @@
+FROM node:22-alpine
+
+WORKDIR /usr/src/app
+RUN echo '{"name": "simple-node-app", "version": "1.0.0"}' > package.json
+RUN npm install
+
+RUN echo 'const { createServer } = require("http");\
+\
+const server = createServer(function (req, res) {\
+	res.writeHead(200, { "Content-Type": "text/plain" });\
+	res.write("Hello from Container A");\
+	res.end();\
+});\
+\
+server.listen(8080);\
+' > app.js
+
+EXPOSE 8080

fixtures/interactive-dev-tests/multi-workers-containers-app/workerA/index.ts

@@ -0,0 +1,38 @@
+import { DurableObject } from "cloudflare:workers";
+
+export class FixtureTestContainerA extends DurableObject<Env> {
+	container: globalThis.Container;
+
+	constructor(ctx: DurableObjectState, env: Env) {
+		super(ctx, env);
+		this.container = ctx.container;
+	}
+
+	async fetch(req: Request) {
+		if (!this.container.running) {
+			this.container.start({
+				entrypoint: ["node", "app.js"],
+				enableInternet: false,
+			});
+			// On the first request we simply start the container and return,
+			// on the following requests the container can actually be accessed.
+			// Note that we do this this way because container.start is not awaitable
+			// meaning that we can't simply wait here for the container to be ready
+			return new Response("Container started");
+		}
+		return this.container
+			.getTcpPort(8080)
+			.fetch("http://foo/bar/baz", { method: "POST", body: "hello" });
+	}
+}
+
+export default {
+	async fetch(request, env): Promise<Response> {
+		const id = env.CONTAINER_A.idFromName("container");
+		const stub = env.CONTAINER_A.get(id);
+		return Response.json({
+			containerAText: await (await stub.fetch(request)).text(),
+			containerBText: await (await env.WORKER_B.fetch(request)).text(),
+		});
+	},
+} satisfies ExportedHandler<Env>;

fixtures/interactive-dev-tests/multi-workers-containers-app/workerA/worker-configuration.d.ts

@@ -0,0 +1,7 @@
+declare namespace Cloudflare {
+	interface Env {
+		CONTAINER_A: DurableObjectNamespace<import(".").FixtureTestContainerA>;
+		WORKER_B: Fetcher;
+	}
+}
+interface Env extends Cloudflare.Env {}

fixtures/interactive-dev-tests/multi-workers-containers-app/workerA/wrangler.jsonc

@@ -0,0 +1,28 @@
+{
+	"name": "worker-a",
+	"main": "index.ts",
+	"compatibility_date": "2025-04-03",
+	"services": [{ "binding": "WORKER_B", "service": "worker-b" }],
+	"containers": [
+		{
+			"image": "./Dockerfile",
+			"class_name": "FixtureTestContainerA",
+			"name": "container",
+			"max_instances": 2,
+		},
+	],
+	"durable_objects": {
+		"bindings": [
+			{
+				"class_name": "FixtureTestContainerA",
+				"name": "CONTAINER_A",
+			},
+		],
+	},
+	"migrations": [
+		{
+			"tag": "v1",
+			"new_sqlite_classes": ["FixtureTestContainerA"],
+		},
+	],
+}

fixtures/interactive-dev-tests/multi-workers-containers-app/workerB/Dockerfile

@@ -0,0 +1,18 @@
+FROM node:22-alpine
+
+WORKDIR /usr/src/app
+RUN echo '{"name": "simple-node-app", "version": "1.0.0"}' > package.json
+RUN npm install
+
+RUN echo 'const { createServer } = require("http");\
+\
+const server = createServer(function (req, res) {\
+	res.writeHead(200, { "Content-Type": "text/plain" });\
+	res.write("Hello from Container B");\
+	res.end();\
+});\
+\
+server.listen(8080);\
+' > app.js
+
+EXPOSE 8080

fixtures/interactive-dev-tests/multi-workers-containers-app/workerB/index.ts

@@ -0,0 +1,35 @@
+import { DurableObject } from "cloudflare:workers";
+
+export class FixtureTestContainerB extends DurableObject<Env> {
+	container: globalThis.Container;
+
+	constructor(ctx: DurableObjectState, env: Env) {
+		super(ctx, env);
+		this.container = ctx.container;
+	}
+
+	async fetch(req: Request) {
+		if (!this.container.running) {
+			this.container.start({
+				entrypoint: ["node", "app.js"],
+				enableInternet: false,
+			});
+			// On the first request we simply start the container and return,
+			// on the following requests the container can actually be accessed.
+			// Note that we do this this way because container.start is not awaitable
+			// meaning that we can't simply wait here for the container to be ready
+			return new Response("Container started");
+		}
+		return this.container
+			.getTcpPort(8080)
+			.fetch("http://foo/bar/baz", { method: "POST", body: "hello" });
+	}
+}
+
+export default {
+	async fetch(request, env): Promise<Response> {
+		const id = env.CONTAINER_B.idFromName("container");
+		const stub = env.CONTAINER_B.get(id);
+		return stub.fetch(request);
+	},
+} satisfies ExportedHandler<Env>;

fixtures/interactive-dev-tests/multi-workers-containers-app/workerB/worker-configuration.d.ts

@@ -0,0 +1,6 @@
+declare namespace Cloudflare {
+	interface Env {
+		CONTAINER_B: DurableObjectNamespace<import(".").FixtureTestContainerB>;
+	}
+}
+interface Env extends Cloudflare.Env {}