64fc8b02e3
DESCRIPTION: As part of bringing libnetwork bridge driver features in parity with docker/daemon/network/driver/bridge features (Issue #46), this commit addresses the bridge.RequestPort() API. Currenlty docker/api/server.go needs an hold of port allocator in order to reserve a transport port which will be used by the http server on the host machine, so that portallocator does not give out that port when queried by portmapper as part of network driver operations. ISSUE: Current implementation in docker is server.go directly access portmapper and then portallocator from bridge pkg calling bridge.RequestPort(). This also forces that function to trigger portmapper initialization (in case bridge init() was not executed yet), while portmapper life cycle should only be controlled by bridge network driver. We cannot mantain this behavior with libnetwrok as this violates the modularization of networking code which libnetwork is bringing in. FIX: Make portallocator a singleton, now both docker core and portmapper code can initialize it and get the only one instance (Change in docker core code will happen when docker code will migrate to use libnetwork), given it is being used for host specific needs. NOTE: Long term fix is having multiple portallocator instances (so no more singleton) each capable to be in sync with OS regarding current port allocation. When this change comes, no change whould be required on portallocator' clients side, changes will be confined to portallocator package. Signed-off-by: Alessandro Boch <aboch@docker.com>
libnetwork - networking for containers
Libnetwork provides a native Go implementation for connecting containers
The goal of libnetwork is to deliver a robust Container Network Model that provides a consistent programming interface and the required network abstractions for applications.
NOTE: libnetwork project is under heavy development and is not ready for general use.
Current Status
Please watch this space for updates on the progress.
Currently libnetwork is nothing more than an attempt to modularize the Docker platform's networking subsystem by moving it into libnetwork as a library.
Please refer to the roadmap for more information.
Using libnetwork
There are many networking solutions available to suit a broad range of use-cases. libnetwork uses a driver / plugin model to support all of these solutions while abstracting the complexity of the driver implementations by exposing a simple and consistent Network Model to users.
// Create a new controller instance
controller := libnetwork.New()
// This option is only needed for in-tree drivers. Plugins(in future) will get
// their options through plugin infrastructure.
option := options.Generic{}
driver, err := controller.NewNetworkDriver("simplebridge", option)
if err != nil {
return
}
netOptions := options.Generic{}
// Create a network for containers to join.
network, err := controller.NewNetwork(driver, "network1", netOptions)
if err != nil {
return
}
// For a new container: create a sandbox instance (providing a unique key).
// For linux it is a filesystem path
networkPath := "/var/lib/docker/.../4d23e"
networkNamespace, err := sandbox.NewSandbox(networkPath)
if err != nil {
return
}
// For each new container: allocate IP and interfaces. The returned network
// settings will be used for container infos (inspect and such), as well as
// iptables rules for port publishing.
_, sinfo, err := network.CreateEndpoint("Endpoint1", networkNamespace.Key(), "")
if err != nil {
return
}
// Add interfaces to the namespace.
for _, iface := range sinfo.Interfaces {
if err := networkNamespace.AddInterface(iface); err != nil {
return
}
}
// Set the gateway IP
if err := networkNamespace.SetGateway(sinfo.Gateway); err != nil {
return
}
Future
See the roadmap.
Contributing
Want to hack on libnetwork? Docker's contributions guidelines apply.
Copyright and license
Code and documentation copyright 2015 Docker, inc. Code released under the Apache 2.0 license. Docs released under Creative commons.