check command line at show creation about circus HOT 5 CLOSED

I don't think that's very robust because you can't guess everything

instead, what about a dry run mode ? where we run everything for a few seconds and stop everything, just to make sure everything is sane.

from circus.

this is the case actually, the OSError is catched and stop after the retry limit (by default 5) .

I was thinking to use something like:

def check_cmd(cmd, env=None):

    os_env = os.environ
    if isinstance(env, dict):
        os_env.update(env)

    cmd_path = cmd.split(None)[0]

    if os.path.isabs(cmd_path) and os.path.exists(cmd_path):
        return True 


    if os.path.dirname(path):
        path = os.path.normpath(os.path.realpath(cmd_path))
        if os.path.exists(path):
            return True

    env_path = os_env.get('PATH')
    if not env_path:
        # we can't do anything here. 
        return True

    for path in paths.split(os.pathsep):
        filename = os.path.join(path, cmd_path)
        if os.access(filename, os.X_OK):
            return True
   return False

which does that. The idea is to return an error first instead of creating a show. Not sure if it's really important there since we can update dynamically the command or remove a show though.

from circus.

mmm... knowing that the file exist don't make it a valid program -- I am not sure this is very useful since the real validation is actually running the program with the configured options.

from circus.

the idea is to test common mistakes like forgetting a / at startup or giving wrong path). We could also test the executable bit eventually. With that we could remove extra time check due to retries.

from circus.

it's already handled somehow by Popen. Let's close it for now.

from circus.