jupyterlab/binder/jupyter_notebook_config.py

common = [
    '--no-browser',
    '--debug',
    '--port={port}',
    '--ServerApp.ip=127.0.0.1',
    '--ServerApp.token=""',
    # Disable dns rebinding protection here, since our 'Host' header
    # is not going to be localhost when coming from hub.mybinder.org
    '--ServerApp.allow_remote_access=True'
]

lab_command = ' '.join([
    'jupyter',
    'lab',
    '--dev-mode',
    '--extensions-in-dev-mode',
    '--collaborative',
    '--ServerApp.base_url={base_url}lab-dev',
] + common + ['>jupyterlab-dev.log 2>&1'])


lab_splice_command = ' '.join([
    'jupyter',
    'lab',
    'build',
    '--splice-source',
    '--minimize=False',
    '--dev-build=True',
    '--debug',
    '>jupyterlab-spliced.log 2>&1',
    '&&',
    'jupyter',
    'lab',
    '--ServerApp.base_url={base_url}lab-spliced',
] + common + ['>jupyterlab-spliced.log 2>&1'])


c.ServerProxy.servers = {
    'lab-dev': {
        'command': [
            '/bin/bash', '-c', lab_command
        ],
        'timeout': 60,
        'absolute_url': True
    },
    'lab-spliced': {
        'command': [
            '/bin/bash', '-c', lab_splice_command
        ],
        'timeout': 300,
        'absolute_url': True
    }
}

c.NotebookApp.default_url = '/lab-dev'

import logging
c.NotebookApp.log_level = logging.DEBUG