dockerodeExample.js

// no error handling
// code not checked to be working - just to illustrate how to do it

const crypto = require("crypto");
const mkdirp = require("mkdirp-promise");
const io = require("socket.io")();
const fs = require("fs");
const Docker = require("dockerode");
const byline = require("byline");
const StringDecoder = require("string_decoder").StringDecoder;

// using the unix socket interface
const docker = new Docker({ socketPath: "/var/run/docker.sock" });
const decoder = new StringDecoder("utf8");

io.on("connection", socket => {
  socket.on("code-recieved", async function(code) {
    const uniqueId = crypto.randomBytes(16).toString("hex");
    await mkdirp(`/tmp/${uniqueId}`);
    fs.writeFileSync(`/tmp/${uniqueId}/exec.chpl`, code, "utf8");

    docker.createContainer(
      {
        Image: "chapel-latest",
        name: uniqueId,
        Cmd: ["/bin/bash", "runner.sh"],
        Tty: true,
        Binds: ["/tmp:/tmp"],
        Env: [`UNIQUE_ID=${uniqueId}`]
      },
      (err, container) => {
        container.attach(
          { stream: true, stdout: true, stderr: true },
          (err, stream) => {
            byline(stream).on("data", line => {
              // data decoded but not cleaned (removing color codes)
              // not adapted to HTML either (replacing newline character occurences with <br />
              const decodedData = decoder.write(line);
              socket.emit("outputStream", {
                uniqueId,
                type: "data",
                stream: decodedData
              });
            });

            byline(stream).on("error", line => {
              const decodedData = decoder.write(line);
              socket.emit("outputStream", {
                uniqueId,
                type: "error",
                stream: decodedData
              });
            });

            stream.on("end", () => {
              socket.emit("outputStream", { uniqueId, type: "exit" });
            });

            container.start((err, data) => {});
          }
        );
      }
    );
  });
});

// start socket server
io.listen(3000);

runner.sh

chpl -o code /tmp/$UNIQUE_ID/exec.chpl
chmod +x code 
./code