nemea-modulesinfo.in

#!/usr/bin/python3
# -*- coding: utf-8; -*-

"""Print Nemea modules info from supervisor. Optionally limit output
to info on supplied module names."""

__author__ = 'Ulrik Haugen <ulrik.haugen@liu.se>'
__copyright__ = 'Copyright 2017 Linköpings universitet'

import pprint as prettyprint


bindir="@bindir@"


def encodeunicode(element, context, maxlevels, level):
    """Encode unicode strings when pretty printing."""
    if prettyprint._type(element) is unicode:
        element = element.encode()
    return prettyprint._safe_repr(element, context, maxlevels, level)


def setuppprint():
    """Setup pprint to use encodeunicode."""
    global pprint
    prettyprinter = prettyprint.PrettyPrinter()
    prettyprinter.format = encodeunicode
    pprint = prettyprinter.pprint


def getnemeamodulesinfo():
    """Call supervisor_cli for modules info and parse the returned
    json."""
    from subprocess import Popen, PIPE
    from json import loads
    from os.path import join

    supervisorproc = Popen([ join(bindir, "supervisor_cli"), "-i", ],
                           stdout=PIPE, stderr=PIPE)
    modulesinfojson, supervisorerr = supervisorproc.communicate()

    if supervisorerr.strip() or supervisorproc.returncode:
        raise EnvironmentError("Error retrieving modules info,"
                               " supervisor returned %d, stderr: \n%s"
                               % (supervisorproc.returncode,
                                  supervisorerr.strip()))

    return loads(modulesinfojson)


def selectmodulesinfo(modulesinfo, modulesrequested):
    """Select data from _modulesinfo_, limited to modules in the set
    _modulesrequested_ unless empty, return tuple of selected data and
    warnings."""
    selectedmodulesinfo = None
    warnings = []

    if modulesrequested:
        if not modulesrequested.issubset(modulesinfo.keys()):
            warnings.append("Warning: No info on module(s): %s\n"
                            % ", ".join(sorted(modulesrequested.difference(
                                modulesinfo.keys()))))
        if len(modulesrequested) == 1:
            selectedmodulesinfo = modulesinfo[list(modulesrequested)[0]]
        else:
            selectedmodulesinfo = {
                modulename: moduleinfo
                for modulename, moduleinfo in modulesinfo.iteritems()
                if modulename.encode() in modulesrequested }
    else:
        selectedmodulesinfo = modulesinfo

    return selectedmodulesinfo, warnings


def usage(programname):
    """Print usage."""
    print "usage: %s [ modulename ] ...\n\n%s" % (programname, __doc__)


def main(programname, *programargs, **kwargs):
    """Dispatch to printmodulesinfo, print errors/warnings to keyword arg
    _errout_."""
    import os
    if ('-h' in programargs) or ('--help' in programargs):
        usage(programname)
        return os.EX_USAGE

    errout = kwargs['errout']

    setuppprint()
    selectedmodulesinfo, warnings = selectmodulesinfo(getnemeamodulesinfo(),
                                                      frozenset(programargs))
    for warning in warnings: errout.write(warning)
    pprint(selectedmodulesinfo)
    if warnings:
        return os.EX_DATAERR
    return os.EX_OK


if __name__ == '__main__':
    import sys
    sys.exit(main(*sys.argv, errout = sys.stderr))