Inject an init script

It's very basic for the moment

Ref #1089

gns3server/modules/docker/docker_vm.py

@@ -34,7 +34,7 @@ from ..adapters.ethernet_adapter import EthernetAdapter
 from ..nios.nio_udp import NIOUDP
 from ...utils.asyncio.telnet_server import AsyncioTelnetServer
 from ...utils.asyncio import wait_for_file_creation
-
+from ...utils.get_resource import get_resource
 from ...ubridge.ubridge_error import UbridgeError, UbridgeNamespaceError
 
 
@@ -156,6 +156,9 @@ class DockerVM(BaseVM):
         :returns: Return the path that we need to map to local folders
         """
         binds = []
+
+        binds.append("{}:/gns3:ro".format(get_resource("modules/docker/resources")))
+
         volumes = image_infos.get("ContainerConfig", {}).get("Volumes")
         if volumes is None:
             return binds
@@ -163,6 +166,7 @@ class DockerVM(BaseVM):
             source = os.path.join(self.working_dir, os.path.relpath(volume, "/"))
             os.makedirs(source, exist_ok=True)
             binds.append("{}:{}".format(source, volume))
+
         return binds
 
     @asyncio.coroutine
@@ -190,10 +194,17 @@ class DockerVM(BaseVM):
                 "Binds": self._mount_binds(image_infos)
             },
             "Volumes": {},
-            "Env": []
+            "Env": [],
+            "Cmd": image_infos.get("ContainerConfig", {"Cmd": []})["Cmd"]
         }
+
+        params["Cmd"].insert(0, "/bin/sh")
+        params["Cmd"].insert(1, "/gns3/init.sh")
         if self._start_command:
-            params.update({"Cmd": shlex.split(self._start_command)})
+            params["Cmd"] += shlex.split(self._start_command)
+        else:
+            if len(params["Cmd"]) == 2:
+                params["Cmd"] += ["/bin/sh"]
 
         if self._environment:
             params["Env"] += [e.strip() for e in self._environment.split("\n")]

gns3server/modules/docker/resources/init.sh

@@ -0,0 +1,46 @@
+#!/bin/sh
+#
+# Copyright (C) 2016 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#
+# This script is injected into the container and launch before
+# the start command of the container
+#
+
+# Wait 2 seconds to settle the network interfaces
+sleep 2
+
+# /etc/hosts
+[ -s /etc/hosts ] || cat > /etc/hosts << __EOF__
+127.0.1.1	$HOSTNAME
+127.0.0.1	localhost
+::1	localhost ip6-localhost ip6-loopback
+fe00::0	ip6-localnet
+ff00::0	ip6-mcastprefix
+ff02::1	ip6-allnodes
+ff02::2	ip6-allrouters
+__EOF__
+
+# configure loopback interface
+ip link set dev lo up
+
+# configure eth interfaces
+sed -n 's/^ *\(eth[0-9]*\):.*/\1/p' < /proc/net/dev | while read dev; do
+	ip link set dev $dev up
+done
+
+# continue normal docker startup
+/bin/sh -c "$@"