conductor

script.js (1227B)

---

 // src/worker/script.js - turning a task's commands into a shell script
 //
 // The script is copied into the container and run by path rather than
 // piped to the shell's stdin, so that a command which itself reads stdin
 // cannot swallow the rest of the script.
 //
 // It lives outside the tree, so that a repository cannot shadow it and
 // nothing the task does to its own working directory can lose it.
 
 // Single quoting is the only form that is safe for arbitrary text in POSIX
 // sh: everything inside is literal, and an embedded quote is closed,
 // escaped and reopened.
 export function shellQuote(value) {
   return `'${String(value).replace(/'/g, "'\\''")}'`;
 }
 
 // Each command is echoed before it runs, so a reader can tell which one
 // produced what. set -e stops at the first failure, and the exit code of
 // that command becomes the exit code of the script.
 export function buildScript(commands) {
   const lines = ['#!/bin/sh', 'set -e', ''];
   for (const command of commands) {
     lines.push(`printf '%s\\n' ${shellQuote(`$ ${command}`)}`);
     lines.push(command);
     lines.push('');
   }
   return lines.join('\n');
 }
 
 export const SCRIPT_NAME = 'entrypoint.sh';
 export const SCRIPT_PATH = `/tmp/${SCRIPT_NAME}`;