Update example to use npm packages via package.json (#525)

## Summary
- Replace deprecated `deno.land/std@0.77.0` HTTP server with a modern example using npm packages
- Add `package.json` with express, chalk, and lodash-es to showcase Deno's npm compatibility
- Remove unused `deps.ts`
- Dockerfile caches `package.json` + `deno install` as a separate layer for efficient rebuilds
- Move `USER deno` after dependency install to avoid permission issues with `node_modules`

Closes #424

Author: bartlomieju

example/Dockerfile

@@ -5,17 +5,16 @@ EXPOSE 1993
 
 WORKDIR /app
 
-# Prefer not to run as root.
-USER deno
-
-# Cache the dependencies as a layer (the following two steps are re-run only when deps.ts is modified).
-# Ideally cache deps.ts will download and compile _all_ external files used in main.ts.
-COPY deps.ts .
-RUN deno install --entrypoint deps.ts
+# Cache dependencies as a layer (re-run only when package.json changes).
+COPY package.json .
+RUN deno install
 
 # These steps will be re-run upon each file change in your working directory:
 COPY . .
 # Compile the main app so that it doesn't need to be compiled each startup/entry.
 RUN deno cache main.ts
 
-CMD ["run", "--allow-net", "main.ts"]
+# Prefer not to run as root.
+USER deno
+
+CMD ["run", "--allow-net", "--allow-read", "--allow-env", "main.ts"]

example/README.md

@@ -1,7 +1,9 @@
+This example demonstrates using Deno with npm packages via `package.json`.
+
 The CMD line in the Dockerfile determines parameters passed to Deno.
 
 ```
-CMD ["run", "--allow-net", "main.ts"]
+CMD ["run", "--allow-net", "--allow-read", "--allow-env", "main.ts"]
 ```
 
 Note: That the listen port (1993), must match with the EXPOSED port in the
@@ -11,12 +13,12 @@ Run using the build and run commands (you may want to use a more descriptive
 name than `app`):
 
 ```sh
-$ docker build -t app . && docker run -it --init -p 1993:1993 app
+$ docker build -t app . && docker run -it -p 1993:1993 app
 ```
 
 In another terminal or browser you can access:
 
 ```sh
 $ curl localhost:1993
-Hello World
+HELLO WORLD
 ```

example/deps.ts

@@ -1,10 +1,14 @@
-import { serve } from "./deps.ts";
+import express from "express";
+import chalk from "chalk";
+import { upperCase } from "lodash-es";
 
 const PORT = 1993;
-const s = serve(`0.0.0.0:${PORT}`);
-const body = new TextEncoder().encode("Hello World\n");
+const app = express();
 
-console.log(`Server started on port ${PORT}`);
-for await (const req of s) {
-  req.respond({ body });
-}
+app.get("/", (_req, res) => {
+  res.send(upperCase("Hello World") + "\n");
+});
+
+app.listen(PORT, "0.0.0.0", () => {
+  console.log(chalk.green(`Server started on port ${PORT}`));
+});

example/main.ts

@@ -0,0 +1,7 @@
+{
+  "dependencies": {
+    "express": "^4.21.0",
+    "chalk": "^5.4.0",
+    "lodash-es": "^4.17.21"
+  }
+}