Implement config parsing and make a simple listener

.gitignore

@@ -1,4 +1,5 @@
 *.pyc
 *.db
 *.pem
+*.json
 env/

threshold.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python
+from twisted.internet import reactor
+from twisted.internet.ssl import DefaultOpenSSLContextFactory
+from twisted.internet.protocol import Protocol, Factory
+from json import load, dump
+from sys import exit
+
+listener = None
+connections = {}
+
+def log(data):
+    print("[LOG]", data)
+
+def debug(data):
+    print("[DEBUG]", data)
+
+class Base(Protocol):
+    def __init__(self, addr):
+        self.addr = addr
+        self.authed = False
+
+    def send(self, data):
+        data += "\r\n"
+        data = data.encode("utf-8", "replace")
+        self.transport.write(data)
+
+    def dataReceived(self, data):
+        log("Data received from %s:%s -- %s" % (self.addr.host, self.addr.port, data))
+
+    def connectionMade(self):
+        log("Connection from %s:%s" % (self.addr.host, self.addr.port))
+        self.send("Hello.")
+
+    def connectionLost(self, reason):
+        global connections
+        log("Connection lost from %s: %s" % (self.addr.host, reason.getErrorMessage()))
+        if not listener == None:
+            if self.addr in connections.keys():
+                del connections[self.addr]
+            else:
+                debug("Tried to remove a non-existant connection.")
+        else:
+            debug("Tried to remove a connection from a listener that wasn't running.")
+
+class BaseFactory(Factory):
+    def buildProtocol(self, addr):
+        global connections
+        entry = Base(addr)
+        connections[addr] = entry
+        return entry
+
+    def send(self, addr, data):
+        global connections
+        if addr in connections.keys():
+            connection = connections[addr]
+            connection.send(data)
+        else:
+            return
+
+def getconfig():
+    with open("config.json", "r") as f:
+        config = load(f)
+        if set(["port", "bind", "usessl"]).issubset(set(config.keys())):
+            if config["usessl"] == True:
+                if not set(["cert", "key"]).issubset(set(config.keys())):
+                    debug("SSL is on but certificate or key is not defined")
+                    exit(1)
+            return config
+        else:
+            debug("Mandatory values missing from config")
+            exit(1)
+
+if __name__ == "__main__":
+    config = getconfig()
+
+    listener = BaseFactory()
+    if config["usessl"] == True:
+        reactor.listenSSL(config["port"], listener, DefaultOpenSSLContextFactory(config["key"], config["cert"]), interface=config["bind"])
+        log("Threshold running with SSL on %s:%s" % (config["bind"], config["port"]))
+    else:
+        reactor.listen(config["port"], listener, interface=config["bind"])
+        log("Threshold running on %s:%s" % (config["bind"], config["port"]))
+
+    reactor.run()