yarn: migrate sample-nodejs-app example

.dockerignore

@@ -0,0 +1,3 @@
+.git
+node_modules
+

.editorconfig

@@ -0,0 +1,10 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+
+[*.{js,json,yml}]
+charset = utf-8
+indent_style = space
+indent_size = 2

.gitattributes

@@ -0,0 +1,4 @@
+/.yarn/**            linguist-vendored
+/.yarn/releases/*    binary
+/.yarn/plugins/**/*  binary
+/.pnp.*              binary linguist-generated

.gitignore

@@ -18,3 +18,16 @@ CLAUDE.md
 hermeto-output/
 hermeto.env
 
+.yarn/*
+!.yarn/patches
+!.yarn/plugins
+!.yarn/releases
+!.yarn/sdks
+!.yarn/versions
+
+# Swap the comments on the following lines if you wish to use zero-installs
+# In that case, don't forget to run `yarn config set enableGlobalCache false`!
+# Documentation here: https://yarnpkg.com/features/caching#zero-installs
+
+#!.yarn/cache
+.pnp.*

Containerfile

@@ -0,0 +1,11 @@
+FROM docker.io/node:20
+
+COPY . /src
+WORKDIR /src
+
+RUN yarn install
+
+EXPOSE 9000
+
+CMD ["yarn", "run", "start"]
+

README.md

@@ -1,4 +1,10 @@
-# Repo of examples for Hermeto docs
+# Sample NodeJS App
 
-Individual examples each live in their own branch (e.g. the basic `pip` example is in
-the 'pip-basic' branch)
+This is a simple web application based on [Express](https://expressjs.com) used to test container
+builds that rely on the yarn ecossystem.
+
+## How to run it
+```
+yarn install
+yarn start
+```

index.js

@@ -0,0 +1,8 @@
+const express = require("express");
+
+const port = 9000;
+const app = express();
+
+app.get("/", (req, res) => res.send("Hello world!"));
+
+app.listen(port, () => console.log(`App started on port ${port}...`));

package.json

@@ -0,0 +1,16 @@
+{
+  "name": "yarn-basic-example",
+  "packageManager": "yarn@3.6.2",
+  "version": "1.0.0",
+  "description": "A sample NodeJS app",
+  "main": "index.js",
+  "scripts": {
+    "start": "node index.js",
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.18.2"
+  }
+}