import dropbox, pymysql, shlex, shutil, subprocess
from sshtunnel import SSHTunnelForwarder
import iot_config as cfg

def CloseLocalDB():
    localcur.close()
    localdb.close()

def CloseRemoteDB():
    # Disconnect from the database
#    remotecur.close()
#    remotedb.close()
    # Close the SSH tunnel
#    ssh.close()
    print("end of CloseRemoteDB function")

def OpenLocalDB():
    global localcur, localdb
    localdb = pymysql.connect(host=cfg.localdbconn['host'], user=cfg.localdbconn['user'], passwd=cfg.localdbconn['passwd'], db=cfg.localdbconn['db'])
    localcur = localdb.cursor()

def OpenRemoteDB():
    global remotecur, remotedb
    with SSHTunnelForwarder(
            ('my_remote_site', 22),
            ssh_username = "my_ssh_username",
            ssh_private_key = "/etc/ssh/my_private_key.ppk",
            ssh_private_key_password = "my_private_key_password",
            remote_bind_address = ('127.0.0.1', 3308)) as server:
        remotedb = None
#Following line gives an error if uncommented
#        remotedb = pymysql.connect(host='127.0.0.1', user='remote_db_user', passwd='remote_db_password', db='remote_db_name', port=server.local_bind_port)
        #remotecur = remotedb.cursor()

# Main program starts here
OpenLocalDB()
CloseLocalDB()
OpenRemoteDB()
CloseRemoteDB()

2016-04-21 19:13:33,487 | ERROR   | Secsh channel 0 open FAILED: Connection refused: Connect failed
2016-04-21 19:13:33,553 | ERROR   | In #1 <-- ('127.0.0.1', 60591) to ('127.0.0.1', 3308) failed: ChannelException(2, 'Connect failed')
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 60591)
Traceback (most recent call last):
  File "/usr/local/lib/python3.4/dist-packages/sshtunnel.py", line 286, in handle
    src_address)
  File "/usr/local/lib/python3.4/dist-packages/paramiko/transport.py", line 834, in open_channel
    raise e
paramiko.ssh_exception.ChannelException: (2, 'Connect failed')

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.4/socketserver.py", line 613, in process_request_thread
    self.finish_request(request, client_address)
  File "/usr/lib/python3.4/socketserver.py", line 344, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/usr/lib/python3.4/socketserver.py", line 669, in __init__
    self.handle()
  File "/usr/local/lib/python3.4/dist-packages/sshtunnel.py", line 296, in handle
    raise HandlerSSHTunnelForwarderError(msg)
sshtunnel.HandlerSSHTunnelForwarderError: In #1 <-- ('127.0.0.1', 60591) to ('127.0.0.1', 3308) failed: ChannelException(2, 'Connect failed')
----------------------------------------
Traceback (most recent call last):
  File "/home/pi/Documents/iot_pm2/iot_ssh_example_for_help.py", line 38, in <module>
    OpenRemoteDB()
  File "/home/pi/Documents/iot_pm2/iot_ssh_example_for_help.py", line 32, in OpenRemoteDB
    remotedb = pymysql.connect(host='127.0.0.1', user='remote_db_user', passwd='remote_db_password', db='remote_db_name', port=server.local_bind_port)
  File "/usr/local/lib/python3.4/dist-packages/pymysql/__init__.py", line 88, in Connect
    return Connection(*args, **kwargs)
  File "/usr/local/lib/python3.4/dist-packages/pymysql/connections.py", line 678, in __init__
    self.connect()
  File "/usr/local/lib/python3.4/dist-packages/pymysql/connections.py", line 889, in connect
    self._get_server_information()
  File "/usr/local/lib/python3.4/dist-packages/pymysql/connections.py", line 1190, in _get_server_information
    packet = self._read_packet()
  File "/usr/local/lib/python3.4/dist-packages/pymysql/connections.py", line 945, in _read_packet
    packet_header = self._read_bytes(4)
  File "/usr/local/lib/python3.4/dist-packages/pymysql/connections.py", line 981, in _read_bytes
    2013, "Lost connection to MySQL server during query")
pymysql.err.OperationalError: (2013, 'Lost connection to MySQL server during query')