Calculate the IPv6 addreesses needed on a bridge, then reconcile them with the addresses on an existing bridge by deleting then adding as required. (Previously, required addresses were added one-by-one, then unwanted addresses were removed. This meant the daemon failed to start if, for example, an existing bridge had address '2000:db8::/64' and the config was changed to '2000:db8::/80'.) IPv6 addresses are now calculated and applied in one go, so there's no need for setupVerifyAndReconcile() to check the set of IPv6 addresses on the bridge. And, it was guarded by !config.InhibitIPv4, which can't have been right. So, removed its IPv6 parts, and added IPv4 to its name. Link local addresses, the example given in the original ticket, are now released when containers are stopped. Not releasing them meant that when using an LL subnet on the default bridge, no container could be started after a container was stopped (because the calculated address could not be re-allocated). In non-default bridge networks using an LL subnet, addresses leaked. Linux always uses the standard 'fe80::/64' LL network. So, if a bridge is configured with an LL subnet prefix that overlaps with it, a config error is reported. Non-overlapping LL subnet prefixes are allowed. Signed-off-by: Rob Murray <rob.murray@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.
Design
Please refer to the design 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.
package main
import (
"fmt"
"log"
"github.com/docker/docker/libnetwork"
"github.com/docker/docker/libnetwork/config"
"github.com/docker/docker/libnetwork/netlabel"
"github.com/docker/docker/libnetwork/options"
)
func main() {
// Select and configure the network driver
networkType := "bridge"
// Create a new controller instance
driverOptions := options.Generic{}
genericOption := make(map[string]interface{})
genericOption[netlabel.GenericData] = driverOptions
controller, err := libnetwork.New(config.OptionDriverConfig(networkType, genericOption))
if err != nil {
log.Fatalf("libnetwork.New: %s", err)
}
// Create a network for containers to join.
// NewNetwork accepts Variadic optional arguments that libnetwork and Drivers can use.
network, err := controller.NewNetwork(networkType, "network1", "")
if err != nil {
log.Fatalf("controller.NewNetwork: %s", err)
}
// 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. This info is contained or accessible
// from the returned endpoint.
ep, err := network.CreateEndpoint("Endpoint1")
if err != nil {
log.Fatalf("network.CreateEndpoint: %s", err)
}
// Create the sandbox for the container.
// NewSandbox accepts Variadic optional arguments which libnetwork can use.
sbx, err := controller.NewSandbox("container1",
libnetwork.OptionHostname("test"),
libnetwork.OptionDomainname("example.com"))
if err != nil {
log.Fatalf("controller.NewSandbox: %s", err)
}
// A sandbox can join the endpoint via the join api.
err = ep.Join(sbx)
if err != nil {
log.Fatalf("ep.Join: %s", err)
}
// libnetwork client can check the endpoint's operational data via the Info() API
epInfo, err := ep.DriverInfo()
if err != nil {
log.Fatalf("ep.DriverInfo: %s", err)
}
macAddress, ok := epInfo[netlabel.MacAddress]
if !ok {
log.Fatal("failed to get mac address from endpoint info")
}
fmt.Printf("Joined endpoint %s (%s) to sandbox %s (%s)\n", ep.Name(), macAddress, sbx.ContainerID(), sbx.Key())
}
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.