Issue determining temp dir path

[chrisrrowland]

I think there is a strong chance this is not an issue with chrome-launcher, and instead one with my environment, but I'm unsure how to make that determination.

I have an mjs file that when run standalone works fine.

import lighthouse from 'lighthouse';
import * as chromeLauncher from 'chrome-launcher';


(async () => {

    const chrome = await chromeLauncher.launch({
        chromeFlags: ['--headless', '--quiet'],
        chromePath: '/usr/bin/google-chrome-stable', // Specify the path to the Chrome executable in WSL
    });

    // Check if a URL is provided as a command line argument
    if (process.argv.length < 3) {
        console.error('Please provide a URL as a command line argument.');
        process.exit(1);
    }

    const url = process.argv[2]; // Get the URL from the command line argument

    const options = { logLevel: 'info', output: ['html', 'json'], port: chrome.port, tmpdir: '/tmp/' };
    const runnerResult = await lighthouse(url, options);

    // Output the JSON result to stdout
    console.log(JSON.stringify(runnerResult.lhr));

    await chrome.kill();
})();

I also have a python wrapper that invokes the above script, that when run standalone runs fine.

import subprocess
import sys
import json

class LighthouseScanner:
    def scan(self, url):
        try:

            lighthouse_command = f"/home/rowc/.nvm/versions/node/v20.9.0/bin/node sites/lighthouse/LighthouseScanner.mjs {url}"

            # Run the Lighthouse command and capture the output and error
            result = subprocess.run(lighthouse_command, shell=True, text=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

            # Check the exit status
            if result.returncode != 0:
                # If the exit status is non-zero, print the standard error
                print(f"Error running Lighthouse:\n{result.stderr}")
                return None

            # print(result.stdout)
            # Parse the standard output (JSON) into a Python object
            lighthouse_data = json.loads(result.stdout)

            # Print a success message
            print("Lighthouse audit completed successfully.")

            # Return the JSON object
            return lighthouse_data
        except subprocess.CalledProcessError as e:
            # Print an error message if the command fails
            print(f"Error running Lighthouse: {e}")
            return None

# Usage
if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python lighthouse_scanner.py <URL>")
        sys.exit(1)

    url = sys.argv[1]

    scanner = LighthouseScanner()
    print("Scanning URL:", url)
    lighthouse_result = scanner.scan(url)
    if lighthouse_result:
        # Use the lighthouse_result JSON object as needed
        print("Accessibility score:", lighthouse_result["categories"]["accessibility"]["score"])

However, when i run the python code from within its container django application, i get an error. From the bit of reverse engineering I attempted, it appears to be failing to parse the correct user name and mount info from the PATH.

In my particular case I am running pycharm in windows, and my application is using WSL.

Error: EACCES: permission denied, mkdir '/mnt/undefined/Users/undefined/AppData/Local/lighthouse.74073726'
    at mkdirSync (node:fs:1379:3)
    at makeWin32TmpDir (file:///home/rowc/source/repos/mgmt/node_modules/chrome-launcher/dist/utils.js:117:5)
    at makeTmpDir (file:///home/rowc/source/repos/mgmt/node_modules/chrome-launcher/dist/utils.js:66:20)
    at Launcher.makeTmpDir (file:///home/rowc/source/repos/mgmt/node_modules/chrome-launcher/dist/chrome-launcher.js:130:16)
    at Launcher.prepare (file:///home/rowc/source/repos/mgmt/node_modules/chrome-launcher/dist/chrome-launcher.js:137:53)
    at Launcher.launch (file:///home/rowc/source/repos/mgmt/node_modules/chrome-launcher/dist/chrome-launcher.js:197:18)
    at Module.launch (file:///home/rowc/source/repos/mgmt/node_modules/chrome-launcher/dist/chrome-launcher.js:33:20)
    at file:///home/rowc/source/repos/mgmt/sites/lighthouse/LighthouseScanner.mjs:7:41
    at file:///home/rowc/source/repos/mgmt/sites/lighthouse/LighthouseScanner.mjs:27:3
    at ModuleJob.run (node:internal/modules/esm/module_job:217:25) {
  errno: -13,
  syscall: 'mkdir',
  code: 'EACCES',
  path: '/mnt/undefined/Users/undefined/AppData/Local/lighthouse.74073726'
}

I was thinking it might make sense to accept a parameter to specify a temp directory, but I was also wondering if there was an existing solution to this that I was unaware of.

[chrisrrowland]

I was able to get around this by hard coding the same PATH that was being used on the command line into my pycharm setup, though I'm not sure this a real solution or just something that allows me to keep working.

Is there a way to specify a location to use as a temp directory so that I could do that instead?