virtcontainers: Initial import

This is a virtcontainers 1.0.8 import into Kata Containers runtime.

virtcontainers is a Go library designed to manage hardware virtualized
pods and containers. It is the core Clear Containers framework and will
become the core Kata Containers framework, as discussed at
https://github.com/kata-containers/runtime/issues/33

Some more more pointers:

virtcontainers README, including some design and architecure notes:
https://github.com/containers/virtcontainers/blob/master/README.md

virtcontainers 1.0 API:
https://github.com/containers/virtcontainers/blob/master/documentation/api/1.0/api.md

Fixes #40

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

virtcontainers/cni.go

@@ -0,0 +1,179 @@
+//
+// Copyright (c) 2016 Intel Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package virtcontainers
+
+import (
+	"fmt"
+
+	cniTypes "github.com/containernetworking/cni/pkg/types"
+	cniV2Types "github.com/containernetworking/cni/pkg/types/020"
+	cniLatestTypes "github.com/containernetworking/cni/pkg/types/current"
+	cniPlugin "github.com/containers/virtcontainers/pkg/cni"
+	"github.com/sirupsen/logrus"
+)
+
+// CniPrimaryInterface Name chosen for the primary interface
+// If CNI ever support multiple primary interfaces this should be revisited
+const CniPrimaryInterface = "eth0"
+
+// cni is a network implementation for the CNI plugin.
+type cni struct{}
+
+// Logger returns a logrus logger appropriate for logging cni messages
+func (n *cni) Logger() *logrus.Entry {
+	return virtLog.WithField("subsystem", "cni")
+}
+
+func cniDNSToDNSInfo(cniDNS cniTypes.DNS) DNSInfo {
+	return DNSInfo{
+		Servers:  cniDNS.Nameservers,
+		Domain:   cniDNS.Domain,
+		Searches: cniDNS.Search,
+		Options:  cniDNS.Options,
+	}
+}
+
+func convertLatestCNIResult(result *cniLatestTypes.Result) NetworkInfo {
+	return NetworkInfo{
+		DNS: cniDNSToDNSInfo(result.DNS),
+	}
+}
+
+func convertV2CNIResult(result *cniV2Types.Result) NetworkInfo {
+	return NetworkInfo{
+		DNS: cniDNSToDNSInfo(result.DNS),
+	}
+}
+
+func convertCNIResult(cniResult cniTypes.Result) (NetworkInfo, error) {
+	switch result := cniResult.(type) {
+	case *cniLatestTypes.Result:
+		return convertLatestCNIResult(result), nil
+	case *cniV2Types.Result:
+		return convertV2CNIResult(result), nil
+	default:
+		return NetworkInfo{}, fmt.Errorf("Unknown CNI result type %T", result)
+	}
+}
+
+func (n *cni) invokePluginsAdd(pod Pod, networkNS *NetworkNamespace) (*NetworkInfo, error) {
+	netPlugin, err := cniPlugin.NewNetworkPlugin()
+	if err != nil {
+		return nil, err
+	}
+
+	// Note: In the case of multus or cni-genie this will return only the results
+	// corresponding to the primary interface. The remaining results need to be
+	// derived
+	result, err := netPlugin.AddNetwork(pod.id, networkNS.NetNsPath, CniPrimaryInterface)
+	if err != nil {
+		return nil, err
+	}
+
+	netInfo, err := convertCNIResult(result)
+	if err != nil {
+		return nil, err
+	}
+
+	// We do not care about this for now but
+	// If present, the CNI DNS result has to be updated in resolv.conf
+	// if the kubelet has not supplied it already
+	n.Logger().Infof("AddNetwork results %s", result.String())
+
+	return &netInfo, nil
+}
+
+func (n *cni) invokePluginsDelete(pod Pod, networkNS NetworkNamespace) error {
+	netPlugin, err := cniPlugin.NewNetworkPlugin()
+	if err != nil {
+		return err
+	}
+
+	err = netPlugin.RemoveNetwork(pod.id, networkNS.NetNsPath, CniPrimaryInterface)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (n *cni) updateEndpointsFromScan(networkNS *NetworkNamespace, netInfo *NetworkInfo, config NetworkConfig) error {
+	endpoints, err := createEndpointsFromScan(networkNS.NetNsPath, config)
+	if err != nil {
+		return err
+	}
+
+	for _, endpoint := range endpoints {
+		if CniPrimaryInterface == endpoint.Name() {
+			prop := endpoint.Properties()
+			prop.DNS = netInfo.DNS
+			endpoint.SetProperties(prop)
+			break
+		}
+	}
+
+	networkNS.Endpoints = endpoints
+	return nil
+}
+
+// init initializes the network, setting a new network namespace for the CNI network.
+func (n *cni) init(config NetworkConfig) (string, bool, error) {
+	return initNetworkCommon(config)
+}
+
+// run runs a callback in the specified network namespace.
+func (n *cni) run(networkNSPath string, cb func() error) error {
+	return runNetworkCommon(networkNSPath, cb)
+}
+
+// add adds all needed interfaces inside the network namespace for the CNI network.
+func (n *cni) add(pod Pod, config NetworkConfig, netNsPath string, netNsCreated bool) (NetworkNamespace, error) {
+
+	networkNS := NetworkNamespace{
+		NetNsPath:    netNsPath,
+		NetNsCreated: netNsCreated,
+	}
+
+	netInfo, err := n.invokePluginsAdd(pod, &networkNS)
+	if err != nil {
+		return NetworkNamespace{}, err
+	}
+
+	if err := n.updateEndpointsFromScan(&networkNS, netInfo, config); err != nil {
+		return NetworkNamespace{}, err
+	}
+
+	if err := addNetworkCommon(pod, &networkNS); err != nil {
+		return NetworkNamespace{}, err
+	}
+
+	return networkNS, nil
+}
+
+// remove unbridges and deletes TAP interfaces. It also removes virtual network
+// interfaces and deletes the network namespace for the CNI network.
+func (n *cni) remove(pod Pod, networkNS NetworkNamespace) error {
+	if err := removeNetworkCommon(networkNS); err != nil {
+		return err
+	}
+
+	if err := n.invokePluginsDelete(pod, networkNS); err != nil {
+		return err
+	}
+
+	return deleteNetNS(networkNS.NetNsPath, true)
+}