lwneal · January 16, 2024 22:46 · lwneal · Jan 14, 2024
diff --git a/bashfile b/bashfile
 #!/bin/bash
 # ^
 # There's nothing magical about shebang (#!) lines- they just tell the shell which executable should be used to run this script

 # The <<EOF syntax is called a heredoc (https://en.wikipedia.org/wiki/Here_document)
 # It allows us to conveniently cat a large amount of text
 # Let's use a heredoc to write the Dockerfile
 cat >Dockerfile <<'EOF'
 # syntax = docker/dockerfile:1.4.0

 FROM node:20

 WORKDIR /root

 RUN npm install sqlite3

 # We can write any text inside a heredoc- including other heredocs!
 RUN cat >/root/schema.sql <<'EOSQL'
 CREATE TABLE IF NOT EXISTS clicks (
  id   INTEGER PRIMARY KEY AUTOINCREMENT,
  time INTEGER NOT NULL
 );
 EOSQL

 # The heredoc terminator doesn't need to be "EOF", it's just an arbitrary string
 RUN cat >/root/server.js <<'BANANACAT'
  const fs = require("fs");
  const http = require("http");
  const sqlite3 = require("sqlite3");

  const db = new sqlite3.Database(":memory:");
  db.run(fs.readFileSync("/root/schema.sql", "utf8"));

  const html = fs.readFileSync("/root/index.html", "utf8");
  const server = http.createServer((req, res) => {
    db.run("INSERT INTO clicks(time) VALUES(unixepoch())");

    const data = [];
    db.each(
      "SELECT time as t, COUNT(*) as n FROM clicks WHERE t > unixepoch()-4*60*60 GROUP BY t-t%60",
      (_, { t, n }) => data.push([Math.floor(t/60), n]),
      () => {
        res.writeHead(200, { "content-type": "text/html" });
        res.end(html.replace("__DATA__", JSON.stringify(data)));
      },
    );
  });

  server.listen(8080, "", () => console.log("serving :8080..."));
 BANANACAT

 RUN cat >/root/index.html <<'EOHTML'
 <!DOCTYPE html>
 <html>
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>#!/usr/bin/env docker run</title>
  </head>
  <body style="font-family: monospace; font-size; 12px; ">
    <div style="position: absolute; top: 0; left: 0; width: 100vw; height: 100vh; background-size: 5vh 5vh; background-image: linear-gradient(to right, #f0f0f0 1px, transparent 1px), linear-gradient(to bottom, #f0f0f0 1px, transparent 1px); "></div>
    <span style="position: absolute; top: 1vh; left: 5vh;">Page loads over time (last 4 hours)</span>
    <span id="max" style="position: absolute; top: 5vh; left: 1vh;"></span>
    <span id="min" style="position: absolute; top: 95vh; left: 1vh;">0</span>
    <canvas id="canvas" style="position: absolute; top: 5vh; left: 5vw; "></canvas>
    <script>
      (() => {
        const el = document.getElementById("canvas"), ctx = el.getContext("2d");
        el.width = 0.9 * window.innerWidth * window.devicePixelRatio;
        el.height = 0.9 * window.innerHeight * window.devicePixelRatio;
        ctx.scale(window.devicePixelRatio, window.devicePixelRatio);

        const data = __DATA__;
        const max = data.reduce((prev, [_, n]) => (n > prev ? n : prev), 0);
        document.getElementById("max").innerText = max;

        ctx.beginPath();
        ctx.moveTo(0, el.height);

        const draw = (t, n) => {
          const [x, y] = [el.width * (t-data[0][0])/240, el.height * (1 - n/max)];
          ctx.lineTo(x, y);
          ctx.moveTo(x, y);
        }

        let last = -1;
        for (const [t, n] of data) {
          if (last != -1 && t > last + 1) {
            draw(last + 0.1, 0);
            draw(t - 0.1, 0);
          }
          draw(t, n);
          last = t;
        }
        ctx.stroke();
      })();
    </script>
  </body>
 </html>
 EOHTML

 CMD ["node", "/root/server.js"]
 EOF

 # Build the Docker image
 docker build -t myimage .

 # Run a Docker container from the built image
 docker run -p 8080:8080 -it --rm myimage
	#!/bin/bash
	# ^
	# There's nothing magical about shebang (#!) lines- they just tell the shell which executable should be used to run this script

	# The <<EOF syntax is called a heredoc (https://en.wikipedia.org/wiki/Here_document)
	# It allows us to conveniently cat a large amount of text
	# Let's use a heredoc to write the Dockerfile
	cat >Dockerfile <<'EOF'
	# syntax = docker/dockerfile:1.4.0

	FROM node:20

	WORKDIR /root

	RUN npm install sqlite3

	# We can write any text inside a heredoc- including other heredocs!
	RUN cat >/root/schema.sql <<'EOSQL'
	CREATE TABLE IF NOT EXISTS clicks (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	time INTEGER NOT NULL
	);
	EOSQL

	# The heredoc terminator doesn't need to be "EOF", it's just an arbitrary string
	RUN cat >/root/server.js <<'BANANACAT'
	const fs = require("fs");
	const http = require("http");
	const sqlite3 = require("sqlite3");

	const db = new sqlite3.Database(":memory:");
	db.run(fs.readFileSync("/root/schema.sql", "utf8"));

	const html = fs.readFileSync("/root/index.html", "utf8");
	const server = http.createServer((req, res) => {
	db.run("INSERT INTO clicks(time) VALUES(unixepoch())");

	const data = [];
	db.each(
	"SELECT time as t, COUNT() as n FROM clicks WHERE t > unixepoch()-460*60 GROUP BY t-t%60",
	(_, { t, n }) => data.push([Math.floor(t/60), n]),
	() => {
	res.writeHead(200, { "content-type": "text/html" });
	res.end(html.replace("__DATA__", JSON.stringify(data)));
	},
	);
	});

	server.listen(8080, "", () => console.log("serving :8080..."));
	BANANACAT

	RUN cat >/root/index.html <<'EOHTML'
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8" />
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>#!/usr/bin/env docker run</title>
	</head>
	<body style="font-family: monospace; font-size; 12px; ">
	<div style="position: absolute; top: 0; left: 0; width: 100vw; height: 100vh; background-size: 5vh 5vh; background-image: linear-gradient(to right, #f0f0f0 1px, transparent 1px), linear-gradient(to bottom, #f0f0f0 1px, transparent 1px); "></div>
	<span style="position: absolute; top: 1vh; left: 5vh;">Page loads over time (last 4 hours)</span>
	<span id="max" style="position: absolute; top: 5vh; left: 1vh;"></span>
	<span id="min" style="position: absolute; top: 95vh; left: 1vh;">0</span>
	<canvas id="canvas" style="position: absolute; top: 5vh; left: 5vw; "></canvas>
	<script>
	(() => {
	const el = document.getElementById("canvas"), ctx = el.getContext("2d");
	el.width = 0.9 * window.innerWidth * window.devicePixelRatio;
	el.height = 0.9 * window.innerHeight * window.devicePixelRatio;
	ctx.scale(window.devicePixelRatio, window.devicePixelRatio);

	const data = __DATA__;
	const max = data.reduce((prev, [_, n]) => (n > prev ? n : prev), 0);
	document.getElementById("max").innerText = max;

	ctx.beginPath();
	ctx.moveTo(0, el.height);

	const draw = (t, n) => {
	const [x, y] = [el.width * (t-data[0][0])/240, el.height * (1 - n/max)];
	ctx.lineTo(x, y);
	ctx.moveTo(x, y);
	}

	let last = -1;
	for (const [t, n] of data) {
	if (last != -1 && t > last + 1) {
	draw(last + 0.1, 0);
	draw(t - 0.1, 0);
	}
	draw(t, n);
	last = t;
	}
	ctx.stroke();
	})();
	</script>
	</body>
	</html>
	EOHTML

	CMD ["node", "/root/server.js"]
	EOF

	# Build the Docker image
	docker build -t myimage .

	# Run a Docker container from the built image
	docker run -p 8080:8080 -it --rm myimage