Merge pull request #9538 from priyawadhwa/network-flag

Add --network flag to select docker network to run with docker driver

cmd/minikube/cmd/start_flags.go

@@ -107,6 +107,7 @@ const (
 	forceSystemd            = "force-systemd"
 	kicBaseImage            = "base-image"
 	ports                   = "ports"
+	network                 = "network"
 	startNamespace          = "namespace"
 	trace                   = "trace"
 )
@@ -152,6 +153,7 @@ func initMinikubeFlags() {
 	startCmd.Flags().Bool(preload, true, "If set, download tarball of preloaded images if available to improve start time. Defaults to true.")
 	startCmd.Flags().Bool(deleteOnFailure, false, "If set, delete the current cluster if start fails and try again. Defaults to false.")
 	startCmd.Flags().Bool(forceSystemd, false, "If set, force the container runtime to use sytemd as cgroup manager. Currently available for docker and crio. Defaults to false.")
+	startCmd.Flags().StringP(network, "", "", "network to run minikube with. Only available with the docker/podman drivers. If left empty, minikube will create a new network.")
 	startCmd.Flags().StringVarP(&outputFormat, "output", "o", "text", "Format to print stdout in. Options include: [text,json]")
 	startCmd.Flags().StringP(trace, "", "", "Send trace events. Options include: [gcp]")
 }
@@ -293,12 +295,17 @@ func generateClusterConfig(cmd *cobra.Command, existing *config.ClusterConfig, k
 			out.WarningT("With --network-plugin=cni, you will need to provide your own CNI. See --cni flag as a user-friendly alternative")
 		}
 
+		if !driver.IsKIC(drvName) && viper.GetString(network) != "" {
+			out.WarningT("--network flag is only valid with the docker/podman drivers, it will be ignored")
+		}
+
 		cc = config.ClusterConfig{
 			Name:                    ClusterFlagValue(),
 			KeepContext:             viper.GetBool(keepContext),
 			EmbedCerts:              viper.GetBool(embedCerts),
 			MinikubeISO:             viper.GetString(isoURL),
 			KicBaseImage:            viper.GetString(kicBaseImage),
+			Network:                 viper.GetString(network),
 			Memory:                  mem,
 			CPUs:                    viper.GetInt(cpus),
 			DiskSize:                diskSize,

pkg/drivers/kic/kic.go

@@ -86,10 +86,14 @@ func (d *Driver) Create() error {
 		APIServerPort: d.NodeConfig.APIServerPort,
 	}
 
-	if gateway, err := oci.CreateNetwork(d.OCIBinary, d.NodeConfig.ClusterName); err != nil {
+	networkName := d.NodeConfig.Network
+	if networkName == "" {
+		networkName = d.NodeConfig.ClusterName
+	}
+	if gateway, err := oci.CreateNetwork(d.OCIBinary, networkName); err != nil {
 		out.WarningT("Unable to create dedicated network, this might result in cluster IP change after restart: {{.error}}", out.V{"error": err})
-	} else {
-		params.Network = d.NodeConfig.ClusterName
+	} else if gateway != nil {
+		params.Network = networkName
 		ip := gateway.To4()
 		// calculate the container IP based on guessing the machine index
 		ip[3] += byte(driver.IndexFromMachineName(d.NodeConfig.MachineName))

pkg/drivers/kic/oci/network_create.go

@@ -44,7 +44,7 @@ const dockerDefaultBridge = "bridge"
 const podmanDefaultBridge = "podman"
 
 // CreateNetwork creates a network returns gateway and error, minikube creates one network per cluster
-func CreateNetwork(ociBin string, clusterName string) (net.IP, error) {
+func CreateNetwork(ociBin string, networkName string) (net.IP, error) {
 	var defaultBridgeName string
 	if ociBin == Docker {
 		defaultBridgeName = dockerDefaultBridge
@@ -52,9 +52,13 @@ func CreateNetwork(ociBin string, clusterName string) (net.IP, error) {
 	if ociBin == Podman {
 		defaultBridgeName = podmanDefaultBridge
 	}
+	if networkName == defaultBridgeName {
+		klog.Infof("skipping creating network since default network %s was specified", networkName)
+		return nil, nil
+	}
 
 	// check if the network already exists
-	info, err := containerNetworkInspect(ociBin, clusterName)
+	info, err := containerNetworkInspect(ociBin, networkName)
 	if err == nil {
 		klog.Infof("Found existing network %+v", info)
 		return info.gateway, nil
@@ -71,7 +75,7 @@ func CreateNetwork(ociBin string, clusterName string) (net.IP, error) {
 	// Rather than iterate through all of the valid subnets, give up at 20 to avoid a lengthy user delay for something that is unlikely to work.
 	// will be like 192.168.49.0/24 ,...,192.168.239.0/24
 	for attempts < 20 {
-		info.gateway, err = tryCreateDockerNetwork(ociBin, subnetAddr, defaultSubnetMask, info.mtu, clusterName)
+		info.gateway, err = tryCreateDockerNetwork(ociBin, subnetAddr, defaultSubnetMask, info.mtu, networkName)
 		if err == nil {
 			return info.gateway, nil
 		}

pkg/drivers/kic/types.go

@@ -61,5 +61,6 @@ type Config struct {
 	Envs              map[string]string // key,value of environment variables passed to the node
 	KubernetesVersion string            // Kubernetes version to install
 	ContainerRuntime  string            // container runtime kic is running
+	Network           string            //  network to run with kic
 	ExtraArgs         []string          // a list of any extra option to pass to oci binary during creation time, for example --expose 8080...
 }

pkg/minikube/config/types.go

@@ -73,6 +73,7 @@ type ClusterConfig struct {
 	StartHostTimeout        time.Duration
 	ScheduledStop           *ScheduledStopConfig
 	ExposedPorts            []string // Only used by the docker and podman driver
+	Network                 string   // only used by docker driver
 	MultiNodeRequested      bool
 }
 

pkg/minikube/registry/drvs/docker/docker.go

@@ -79,6 +79,7 @@ func configure(cc config.ClusterConfig, n config.Node) (interface{}, error) {
 		KubernetesVersion: cc.KubernetesConfig.KubernetesVersion,
 		ContainerRuntime:  cc.KubernetesConfig.ContainerRuntime,
 		ExtraArgs:         extraArgs,
+		Network:           cc.Network,
 	}), nil
 }
 

site/content/en/docs/commands/start.md

@@ -77,6 +77,7 @@ minikube start [flags]
       --namespace string                  The named space to activate after start (default "default")
       --nat-nic-type string               NIC Type used for nat network. One of Am79C970A, Am79C973, 82540EM, 82543GC, 82545EM, or virtio (virtualbox driver only) (default "virtio")
       --native-ssh                        Use native Golang SSH client (default true). Set to 'false' to use the command line 'ssh' command when accessing the docker machine. Useful for the machine drivers when they will not start with 'Waiting for SSH'. (default true)
+      --network string                    network to run minikube with. Only available with the docker/podman drivers. If left empty, minikube will create a new network.
       --network-plugin string             Kubelet network plug-in to use (default: auto)
       --nfs-share strings                 Local folders to share with Guest via NFS mounts (hyperkit driver only)
       --nfs-shares-root string            Where to root the NFS Shares, defaults to /nfsshares (hyperkit driver only) (default "/nfsshares")

test/integration/kic_custom_network_test.go

+// +build integration
+
+/*
+Copyright 2020 The Kubernetes Authors All rights reserved.
+
+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 integration
+
+import (
+	"context"
+	"fmt"
+	"os/exec"
+	"strings"
+	"testing"
+
+	"k8s.io/minikube/pkg/drivers/kic/oci"
+)
+
+func TestKicCustomNetwork(t *testing.T) {
+	if !KicDriver() {
+		t.Skip("only runs with docker driver")
+	}
+
+	tests := []struct {
+		description string
+		networkName string
+	}{
+		{
+			description: "create custom network",
+		}, {
+			description: "use default bridge network",
+			networkName: "bridge",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.description, func(t *testing.T) {
+			profile := UniqueProfileName("docker-network")
+			ctx, cancel := context.WithTimeout(context.Background(), Minutes(5))
+			defer Cleanup(t, profile, cancel)
+
+			startArgs := []string{"start", "-p", profile, fmt.Sprintf("--network=%s", test.networkName)}
+			c := exec.CommandContext(ctx, Target(), startArgs...)
+			rr, err := Run(t, c)
+			if err != nil {
+				t.Fatalf("%v failed: %v\n%v", rr.Command(), err, rr.Output())
+			}
+			nn := test.networkName
+			if nn == "" {
+				nn = profile
+			}
+			verifyNetworkExists(ctx, t, nn)
+		})
+	}
+}
+
+func TestKicExistingNetwork(t *testing.T) {
+	if !KicDriver() {
+		t.Skip("only runs with docker driver")
+	}
+	// create custom network
+	networkName := "existing-network"
+	if _, err := oci.CreateNetwork(oci.Docker, networkName); err != nil {
+		t.Fatalf("error creating network: %v", err)
+	}
+	defer func() {
+		if err := oci.DeleteKICNetworks(oci.Docker); err != nil {
+			t.Logf("error deleting kic network, may need to delete manually: %v", err)
+		}
+	}()
+	profile := UniqueProfileName("existing-network")
+	ctx, cancel := context.WithTimeout(context.Background(), Minutes(5))
+	defer Cleanup(t, profile, cancel)
+
+	verifyNetworkExists(ctx, t, networkName)
+
+	startArgs := []string{"start", "-p", profile, fmt.Sprintf("--network=%s", networkName)}
+	c := exec.CommandContext(ctx, Target(), startArgs...)
+	rr, err := Run(t, c)
+	if err != nil {
+		t.Fatalf("%v failed: %v\n%v", rr.Command(), err, rr.Output())
+	}
+}
+
+func verifyNetworkExists(ctx context.Context, t *testing.T, networkName string) {
+	c := exec.CommandContext(ctx, "docker", "network", "ls", "--format", "{{.Name}}")
+	rr, err := Run(t, c)
+	if err != nil {
+		t.Fatalf("%v failed: %v\n%v", rr.Command(), err, rr.Output())
+	}
+	if output := rr.Output(); !strings.Contains(output, networkName) {
+		t.Fatalf("%s network is not listed by [%v]: %v", networkName, c.Args, output)
+	}
+}