さくっとDenoを試してみる

Denoの特徴

• JavascriptとTypescriptの実行環境
• Typescriptのコンパイラを内包している(tsc-,ts-nodeなど不要)
• 標準ライブラリーは非同期処理にPromiseを採用
• 実行時に必要な権限のオプション指定が必要
• モジュールの扱いがNode.jsと異なる
• etc

環境構築

Docker

こちらのイメージを使用します。
https://hub.docker.com/r/hayd/deno

Dockerfile

FROM hayd/alpine-deno:1.2.2

# 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 cache deps.ts

# These steps will be re-run upon each file change in your working directory:
ADD . .
# Compile the main app so that it doesn't need to be compiled each startup/entry.
RUN deno cache main.ts

docker-compose.yaml

version: '3'
services:
  app:
    build: .
    command: "run --allow-net --allow-read main.ts"
    ports:
      - "8000:8000"
    volumes:
      - .:/app
    working_dir: "/app"

HelloWorld

main.ts

import { serve } from "./deps.ts";

const PORT =8000;
const s = serve(`0.0.0.0:${PORT}`);
const body = new TextEncoder().encode("Hello World\n");

console.log(`Server started on port ${PORT}`);
for await (const req of s) {
  req.respond({ body });
}

$ docker-compose up -d

APIの作成

Servestを使用
https://github.com/keroxp/servest

main.ts

import { createApp } from "https://servestjs.org/@v1.0.0/mod.ts";
const app = createApp();
app.handle("/", async (req) => {
  await req.respond({
    status: 200,
    headers: new Headers({
      "content-type": "text/plain",
    }),
    body: "hello World!",
  });
});
app.listen({ port:8000 });

参考