@netlify/build/lib/core/lingering.js

Netlify build module

import psList from 'ps-list';
import { logLingeringProcesses } from '../log/messages/core.js';
// Print a warning when some build processes are still running.
// We cannot rely on using the process tree:
//  - This is because it is impossible to know whether a process was a child of
//    another once its parent process has exited. When that happens, the s
//    child becomes inherited by `init`, changing its `ppid`. The information
//    about the original parent is then lost.
//  - The only way to implement this would be to repeatedly list processes as
//    the build command is ongoing. However, this would fail to detect processes
//    spawned just before the build commands ends.
// We cannot list processes before and after the build command and use the
// difference.
//  - This is because other processes (unrelated to @netlify/build) might be
//    running at the same time. This includes OS background processes.
// Therefore, we run this in a controlled environment only (the buildbot) and
// exclude specific processes manually. This is a lesser evil, although still
// quite hacky.
export const warnOnLingeringProcesses = async function ({ mode, logs, testOpts: { silentLingeringProcesses = false }, }) {
    if (mode !== 'buildbot' || silentLingeringProcesses) {
        return;
    }
    const processes = await psList();
    const commands = processes.map(getCommand).filter(isNotIgnoredCommand);
    if (commands.length === 0) {
        return;
    }
    logLingeringProcesses(logs, commands);
};
// `cmd` is only available on Unix. Unlike `name`, it includes the arguments.
const getCommand = function ({ name, cmd = name }) {
    return cmd;
};
// We ignore any command known to be internal to the buildbot.
// We also ignore commands known not to complete properly in builds if they are
// widely used.
const isNotIgnoredCommand = function (command) {
    return !IGNORED_COMMANDS.some((ignoredCommand) => matchesIgnoredCommand(command, ignoredCommand));
};
const matchesIgnoredCommand = function (command, ignoredCommand) {
    if (typeof ignoredCommand === 'string') {
        return command.includes(ignoredCommand);
    }
    return ignoredCommand.test(command);
};
const IGNORED_COMMANDS = [
    // TODO: Those can most likely be removed
    'ps',
    'grep',
    'bash',
    // Internal buildbot commands
    '[build]',
    'sleep 5',
    /buildbot.*\[node]/,
    // buildbot's main Bash script
    '/opt/build-bin/build',
    // `@netlify/build` binary itself
    'netlify-build',
    // Plugin child processes spawned by @netlify/build
    '@netlify/build',
    // Shown for parent processes with currently running child processes.
    // Happens on `ps` itself.
    'defunct',
    // Processes often left running. We should report those but don't because of
    // how common those are in production builds
    'gatsby-telemetry',
    'jest-worker',
    'broccoli-babel-transpiler',
];