Docker Development

This demonstrates usage of the Linux VM with a Docker environment using a sample app.

Pre-requisite

Run script to connect to Linux VM via SSH. Use linuxVMConnectionSetup-SEA or linuxVMConnectionSetup script depending on VM location. Ensure that connection is successful.

Steps

1. Open Visual Studio Code.
2. Display the Terminal.
3. Create a working directory.

mkdir ~/node-docker-app
cd ~/node-docker-app

4. Pull the Node LTS image from Docker.

docker image pull node:lts

5. Run the container.

docker run -it -v `pwd`:`pwd` -w `pwd` -p 127.0.0.1:3000:4000 node:lts sh

This command does the following:

• Starts a Node.js Alpine container.
• Provides interactive shell access (sh) inside the container.
• Mounts the current project directory into the container so changes persist.
• Ensures that files created inside the container appear on the VM.
• Maps port 4000 in the container to 3000 on the VM, but only accessible locally (127.0.0.1).

[!NOTE] The port mapping is needed to call the API later.

6. Initialize the node project.

npm init -y

7. Install Fastify and Typescript dependencies

npm install fastify
npm install --save-dev typescript ts-node @types/node

8. In VS Code, select Explorer then click Open Folder. When prompted select the directory that was created node-docker-app.
9. Verify that package.json, package-lock.json, and node_modules folder are present.
10. Create a tsconfig.json file in the root directory:

{
  "compilerOptions": {
    "target": "ES6",
    "module": "CommonJS",
    "strict": true,
    "outDir": "dist",
    "rootDir": "src",
    "esModuleInterop": true
  }
}

11. In Explorer or Terminal create a src folder and create file: server.ts and add the following:

import Fastify from "fastify";
const fastify = Fastify({ logger: true });
// Define a route
fastify.get("/", async (request, reply) => {
  return { message: "Hello from Fastify + TypeScript inside Docker (Alpine)!" };
});
// Start the server
const start = async () => {
  try {
    await fastify.listen({ port: 4000, host: "0.0.0.0" });
    console.log("Fastify TypeScript server running on port 4000");
  } catch (err) {
    fastify.log.error(err);
    process.exit(1);
  }
};
start();

12. Run the server inside the docker container.

npx ts-node src/server.ts

13. Test the API route:

curl http://127.0.0.1:3000

14. Verify that the following is displayed:

~/code/node-docker-app$ curl http://127.0.0.1:3000
{"message":"Hello from Fastify + TypeScript inside Docker (Alpine)!"}