http.py

#!/usr/bin/python

from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
from subprocess import Popen, PIPE
import argparse
import json
import os
import shlex
import signal
import sys

DEFAULT_PORT = 8080


def sigterm_handler(_signo, _stack_frame):
    # Raises SystemExit(0):
    sys.exit(0)


def get_exitcode_stdout_stderr(cmd, shell=False):
    """
    Execute the external command and get its exitcode, stdout and stderr.
    """
    args = shlex.split(cmd)
    proc = Popen(args, stdout=PIPE, stderr=PIPE, shell=shell,
                 env=dict(os.environ, LC_ALL='C'))
    out, err = proc.communicate()
    exitcode = proc.returncode
    return exitcode, out, err


class myHandler(BaseHTTPRequestHandler):

    # Handler for the GET requests
    def do_GET(self):
        status = 500
        body = {}
        cmd = "ls -1z"
        exitcode, out, err = get_exitcode_stdout_stderr(cmd)
        if exitcode == 0:
            # TODO: module/class for command and its parser
            # https://github.com/influxdata/telegraf/tree/master/plugins/inputs/httpjson
            body["output"] = out
            status = 200
        else:
            body["error"] = {
                "exitcode": exitcode,
                "out": out,
                "err": err,
                "cmd": cmd
            }

        self.send_response(status)
        self.send_header('Content-type', 'application/json')
        self.end_headers()

        self.wfile.write(json.dumps(body))


signal.signal(signal.SIGTERM, sigterm_handler)

parser = argparse.ArgumentParser(description='Very simple http server')
parser.add_argument('-p', '--port', help='TCP port to listen on (default: %d)' %
                    DEFAULT_PORT, type=int,
                    default=DEFAULT_PORT)
args = parser.parse_args()

port = args.port

try:
    # Create a web server and define the handler to manage the
    # incoming request
    server = HTTPServer(('', port), myHandler)
    print('Listening on port %d' % port)

    # Wait forever for incoming htto requests
    server.serve_forever()
except KeyboardInterrupt:
    print('Keyboard interrupt...')
finally:
    server.socket.close()
    print("Goodbye.")