Merge pull request #879 from anarcat/patch-1

document how to change daemon ports

cmd/ipfs/daemon.go

@@ -38,7 +38,27 @@ over the network. Most applications that use IPFS will do so by
 communicating with a daemon over the HTTP API. While the daemon is
 running, calls to 'ipfs' commands will be sent over the network to
 the daemon.
-`,
+
+The daemon will start listening on ports on the network, which are
+documented in (and can be modified through) 'ipfs config Addresses'.
+For example, to change the 'Gateway' port:
+
+    ipfs config Addresses.Gateway /ip4/127.0.0.1/tcp/8082
+
+The API address can be changed the same way:
+
+   ipfs config Addresses.API /ip4/127.0.0.1/tcp/5002
+
+Make sure to restart the daemon after changing addresses.
+
+By default, the gateway is only accessible locally. To expose it to other computers
+in the network, use 0.0.0.0 as the ip address:
+
+   ipfs config Addresses.Gateway /ip4/0.0.0.0/tcp/8080
+
+Be careful if you expose the API. It is a security risk, as anyone could use control 
+your node remotely. If you need to control the node remotely, make sure to protect
+the port as you would other services or database (firewall, authenticated proxy, etc).`,
 	},
 
 	Options: []cmds.Option{