Merge pull request #1597 from kazkansouh/2.2-fix-1595-volumes

Fix for issue #1595

gns3server/compute/docker/docker_vm.py

@@ -248,27 +248,32 @@ class DockerVM(BaseNode):
 
         # We mount our own etc/network
         try:
-            network_config = self._create_network_config()
+            self._create_network_config()
         except OSError as e:
             raise DockerError("Could not create network config in the container: {}".format(e))
-        binds.append("{}:/gns3volumes/etc/network:rw".format(network_config))
+        volumes = ["/etc/network"]
 
-        self._volumes = ["/etc/network"]
-        volumes = list((image_info.get("Config", {}).get("Volumes") or {}).keys())
+        volumes.extend((image_info.get("Config", {}).get("Volumes") or {}).keys())
         for volume in self._extra_volumes:
             if not volume.strip() or volume[0] != "/" or volume.find("..") >= 0:
                 raise DockerError("Persistent volume '{}' has invalid format. It must start with a '/' and not contain '..'.".format(volume))
         volumes.extend(self._extra_volumes)
+
+        self._volumes = []
         # define lambdas for validation checks
         nf = lambda x: re.sub(r"//+", "/", (x if x.endswith("/") else x + "/"))
-        incompatible = lambda v1, v2: nf(v1).startswith(nf(v2)) or nf(v2).startswith(nf(v1))
+        generalises = lambda v1, v2: nf(v2).startswith(nf(v1))
         for volume in volumes:
-            if [ v for v in self._volumes if incompatible(v, volume) ] :
-                raise DockerError("Duplicate persistent volume {} detected.\n\nVolumes specified in docker image as well as user specified persistent volumes must be unique.".format(volume))
+            # remove any mount that is equal or more specific, then append this one
+            self._volumes = list(filter(lambda v: not generalises(volume, v), self._volumes))
+            # if there is nothing more general, append this mount
+            if not [ v for v in self._volumes if generalises(v, volume) ] :
+                self._volumes.append(volume)
+
+        for volume in self._volumes:
             source = os.path.join(self.working_dir, os.path.relpath(volume, "/"))
             os.makedirs(source, exist_ok=True)
             binds.append("{}:/gns3volumes{}".format(source, volume))
-            self._volumes.append(volume)
 
         return binds