Add NginxHandler class with start, stop, restart,

print_config, and setup_config_file methods

app/nginxHandler.py

@@ -0,0 +1,51 @@
+import os
+
+
+class NginxHandler:
+    def __init__(self, config_path):
+        self.config_path = config_path
+
+    def start(self):
+        print('Starting NGINX...')
+        os.system('nginx > /dev/null 2>&1 &')
+        print('NGINX started')
+
+    def stop(self):
+        print('Stopping NGINX...')
+        os.system('nginx -s stop')
+        print('NGINX stopped')
+
+    def restart(self):
+        self.stop()
+        self.start()
+
+    def print_config(self):
+        with open(self.config_path, 'r') as f:
+            print(f.read())
+
+    def setup_config_file(self, port_ip_map, current_container_ip):
+        self.stop()
+        print('Setting up NGINX config file...')
+        print('port_ip_map: {}'.format(port_ip_map))
+        nginx_conf = open(self.config_path, 'w+')
+        nginx_conf.truncate()
+        nginx_conf.write('events { }\n')
+        nginx_conf.write('stream {\n')
+
+        for port in port_ip_map:
+            nginx_conf.write('    upstream upstream_{} {{\n'.format(port))
+            nginx_conf.write('        server {}:{};\n'.format(
+                port_ip_map[port], port))
+            nginx_conf.write(
+                '        server 127.0.0.1:{} backup;\n'.format(port))
+            nginx_conf.write('    }\n')
+
+            nginx_conf.write('    server {\n')
+            nginx_conf.write('        listen {}:{};\n'.format(
+                current_container_ip, port))
+            nginx_conf.write('        proxy_pass upstream_{};\n'.format(port))
+            nginx_conf.write('    }\n')
+        nginx_conf.write('}\n')
+        nginx_conf.close()
+        print('NGINX config file setup')
+        self.start()