fix(services): use COREOS_PUBLIC_IPV4 for advertised IP

Currently, all containers use a hacky method to determine the IP
to advertise to etcd - the method determines the machine's default
route, and uses that IP. However, this can be configured very differently
depending on the environment, and in some cases doesn't work at all.
Instead, we use COREOS_PUBLIC_IPV4, as that is set on every CoreOS host,
and we trust that CoreOS knows the machine's networks better than we do.

fixes #845

Author: carmstrong

scheduler/coreos.py

@@ -223,7 +223,7 @@ def attach(self, name):
 [Service]
 EnvironmentFile=/etc/environment
 ExecStartPre=/bin/sh -c "until /usr/bin/docker port {name} {port} >/dev/null 2>&1; do sleep 2; done; port=$(docker port {name} {port} | cut -d ':' -f2); echo Waiting for $port/tcp...; until netstat -lnt | grep :$port >/dev/null; do sleep 1; done"
-ExecStart=/bin/sh -c "port=$(docker port {name} {port} | cut -d ':' -f2); echo Connected to $COREOS_PUBLIC_IPV4:$port/tcp, publishing to etcd...; while netstat -lnt | grep :$port >/dev/null; do etcdctl set /deis/services/{app}/{name} $COREOS_PUBLIC_IPV4:$port --ttl 60 >/dev/null; sleep 45; done"
+ExecStart=/bin/sh -c "port=$(docker port {name} {port} | cut -d ':' -f2); echo Connected to $COREOS_PRIVATE_IPV4:$port/tcp, publishing to etcd...; while netstat -lnt | grep :$port >/dev/null; do etcdctl set /deis/services/{app}/{name} $COREOS_PRIVATE_IPV4:$port --ttl 60 >/dev/null; sleep 45; done"
 ExecStop=/usr/bin/etcdctl rm --recursive /deis/services/{app}/{name}
 
 [X-Fleet]

systemd/deis-controller.service

@@ -4,9 +4,10 @@ Requires=deis-logger.service deis-builder.service
 After=deis-logger.service deis-builder.service
 
 [Service]
+EnvironmentFile=/etc/environment
 TimeoutStartSec=20m
 ExecStartPre=/bin/sh -c "/usr/bin/docker history deis/controller >/dev/null || /usr/bin/docker pull deis/controller"
-ExecStart=/bin/sh -c "IFACE=$(netstat -nr | grep ^0.0.0.0 | awk '{print $8}') && HOST_IP=$(/bin/ifconfig $IFACE | awk '/inet /{print $2}') && exec /usr/bin/docker run --name deis-controller -p 8000:8000 -e PUBLISH=8000 -e HOST=$HOST_IP --volumes-from=deis-logger deis/controller"
+ExecStart=/bin/sh -c "docker run --name deis-controller -p 8000:8000 -e PUBLISH=8000 -e HOST=$COREOS_PRIVATE_IPV4 --volumes-from=deis-logger deis/controller"
 ExecStop=/usr/bin/docker rm -f deis-controller
 
 [Install]