Preprocess config file and extract value of the given key.

Usage: clickhouse extract-from-config [options]

Allowed options:
  --help                   produce this help message
  --stacktrace             print stack traces of exceptions
  --process-zk-includes    if there are from_zk elements in config, connect to
                           ZooKeeper and process them
  --try                    Do not warn about missing keys, missing users
                           configurations or non existing file from
                           include_from tag
  --users                  Return values from users.xml config
  --log-level arg (=error) log level
  -c [ --config-file ] arg path to config file
  -k [ --key ] arg         key to get value for