init/init_script.py

#==================================================================================

#        Copyright (c) 2018-2019 AT&T Intellectual Property.
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.
#==================================================================================

#
# Author : Ashwin Sridharan
#   Date    : Feb 2019
#


# This initialization script reads in a json from the specified config map path
# to set up the initializations (route config map, variables etc) for the main
# xapp process

import json;
import sys;
import os;
import signal;
import time;
import ast;

def signal_handler(signum, frame):
    print("Received signal {0}\n".format(signum));
    if(xapp_subprocess == None or xapp_pid == None):
        print("No xapp running. Quiting without sending signal to xapp\n");
    else:
        print("Sending signal {0} to xapp ...".format(signum));
        xapp_subprocess.send_signal(signum);
        

def parseConfigJson(config):
    
    for k1 in config.keys():
        if k1 in ParseSection:
            result = ParseSection[k1](config);
            if result == False:
                    return False;

        
#        for k2 in config[k1].keys():
            #print(k2);
#            if k2 in ParseSection:
#                result = ParseSection[k2](config[k1]);
#                if result == False:
#                    return False;


        
def getMessagingInfo(config):
     if 'messaging' in config.keys() and 'ports' in config['messaging'].keys():
        port_list = config['messaging']['ports']
        for portdesc in port_list :
            if 'port' in portdesc.keys() and 'name' in portdesc.keys() and portdesc['name'] == 'rmr-data':
                lport = portdesc['port']
                # Set the environment variable
                os.environ["HW_PORT"] = str(lport)
                return True;
     if lport == 0:
         print("Error! No valid listening port");
         return False;

def getXappName(config):
    myKey = "xapp_name";
    if myKey not in config.keys():
        print(("Error ! No information found for {0} in config\n".format(myKey)));
        return False;

    xapp_name = config[myKey];
    print("Xapp Name is: " + xapp_name); 
    os.environ["XAPP_NAME"] = xapp_name;

default_routing_file = "/tmp/routeinfo/routes.txt";
lport = 0;
ParseSection = {};
ParseSection["xapp_name"] = getXappName;
ParseSection["messaging"] = getMessagingInfo;


#================================================================
if __name__ == "__main__":

    import subprocess;
#    cmd = ["../src/hw_xapp_main"];
    cmd = ["/usr/local/bin/hw_xapp_main"];
        
    if len(sys.argv) > 1:
        config_file = sys.argv[1];
    else:
        print("Error! No configuration file specified\n");
        sys.exit(1);
        
    if len(sys.argv) > 2:
        cmd[0] = sys.argv[2];

    with open(config_file, 'r') as f:
         try:
             config = json.load(f);
         except Exception as e:
             print(("Error loading json file from {0}. Reason = {1}\n".format(config_file, e)));
             sys.exit(1);
             
    result = parseConfigJson(config);
    time.sleep(10);
    if result == False:
        print("Error parsing json. Not executing xAPP");
        sys.exit(1);

    else:

        # Register signal handlers
        signal.signal(signal.SIGINT, signal_handler);
        signal.signal(signal.SIGTERM, signal_handler);

        # Start the xAPP
        #print("Executing xAPP ....");
        xapp_subprocess = subprocess.Popen(cmd, shell = False, stdin=None, stdout=None, stderr = None);
        xapp_pid = xapp_subprocess.pid;

        # Periodically poll the process every 5 seconds to check if still alive
        while(1):
            xapp_status = xapp_subprocess.poll();
            if xapp_status == None:
                time.sleep(5);
            else:
                print("XaPP terminated via signal {0}\n".format(-1 * xapp_status));
                break;