Add support for stats & code cleanup (#297)

* Add support for stats & code cleanup

* Add more stats

* Move code into own object

* Add to API

* Update API

* Add error handling

* fix lint

* fix block io

hassio/misc/dns.py

@@ -0,0 +1,42 @@
+"""Setup the internal DNS service for host applications."""
+import asyncio
+import logging
+import shlex
+
+_LOGGER = logging.getLogger(__name__)
+
+COMMAND = "socat UDP-RECVFROM:53,fork UDP-SENDTO:127.0.0.11:53"
+
+
+class DNSForward(object):
+    """Manage DNS forwarding to internal DNS."""
+
+    def __init__(self, loop):
+        """Initialize DNS forwarding."""
+        self.loop = loop
+        self.proc = None
+
+    async def start(self):
+        """Start DNS forwarding."""
+        try:
+            self.proc = await asyncio.create_subprocess_exec(
+                *shlex.split(COMMAND),
+                stdin=asyncio.subprocess.DEVNULL,
+                stdout=asyncio.subprocess.DEVNULL,
+                stderr=asyncio.subprocess.DEVNULL,
+                loop=self.loop
+            )
+        except OSError as err:
+            _LOGGER.error("Can't start DNS forwarding: %s", err)
+        else:
+            _LOGGER.info("Start DNS port forwarding for host add-ons")
+
+    async def stop(self):
+        """Stop DNS forwarding."""
+        if not self.proc:
+            _LOGGER.warning("DNS forwarding is not running!")
+            return
+
+        self.proc.kill()
+        await self.proc.wait()
+        _LOGGER.info("Stop DNS forwarding")