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Allow using port-forward without specifying local port
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This commit allows using port-forward without specifying any specific port number.

Port forward will listen on a random available port.

Signed-off-by: Alvaro Romero <alromero@redhat.com>
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@alromeros
alromeros committed Aug 16, 2023
1 parent c1e2a2d commit 6f2d4c2
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Showing 6 changed files with 152 additions and 72 deletions.
19 changes: 11 additions & 8 deletions pkg/virtctl/memorydump/memorydump.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,7 @@ const (
storageClassArg = "storage-class"
accessModeArg = "access-mode"
portForwardArg = "port-forward"
localPortArg = "local-port"

configName = "config"
filesystemOverhead = cdiv1.Percent("0.055")
Expand All @@ -62,7 +63,8 @@ const (
var (
claimName string
createClaim bool
portForward string
portForward bool
localPort string
storageClass string
accessMode string
outputFile string
Expand Down Expand Up @@ -115,7 +117,8 @@ func NewMemoryDumpCommand(clientConfig clientcmd.ClientConfig) *cobra.Command {
cmd.SetUsageTemplate(templates.UsageTemplate())
cmd.Flags().StringVar(&claimName, claimNameArg, "", "pvc name to contain the memory dump")
cmd.Flags().BoolVar(&createClaim, createClaimArg, false, "Create the pvc that will conatin the memory dump")
cmd.Flags().StringVar(&portForward, portForwardArg, "", "Configure and set port-forward in the specified port to download the memory dump")
cmd.Flags().BoolVar(&portForward, portForwardArg, false, "Configure and set port-forward in a random port to download the memory dump")
cmd.Flags().StringVar(&localPort, localPortArg, "0", "Specify port for port-forward")
cmd.Flags().StringVar(&storageClass, storageClassArg, "", "The storage class for the PVC.")
cmd.Flags().StringVar(&accessMode, accessModeArg, "", "The access mode for the PVC.")
cmd.Flags().StringVar(&outputFile, "output", "", "Specifies the output path of the memory dump to be downloaded.")
Expand Down Expand Up @@ -330,14 +333,14 @@ func downloadMemoryDump(namespace, vmName string, virtClient kubecli.KubevirtCli
Namespace: namespace,
Name: vmexportName,
ExportSource: exportSource,
PortForward: portForward,
LocalPort: localPort,
}
// Complete port-forward arguments
if portForward != "" {
vmExportInfo.PortForward = portForward
if vmExportInfo.ServiceURL == "" {
vmExportInfo.ServiceURL = fmt.Sprintf("127.0.0.1:%s", portForward)
}

if portForward {
vmExportInfo.ServiceURL = fmt.Sprintf("127.0.0.1:%s", localPort)
}

// User wants the output in a file, create
output, err := os.Create(vmExportInfo.OutputFile)
if err != nil {
Expand Down
42 changes: 42 additions & 0 deletions pkg/virtctl/memorydump/memorydump_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,8 +3,10 @@ package memorydump_test
import (
"context"
"fmt"
"io"
"net/http"
"net/http/httptest"
"strings"
"sync"
"time"

Expand Down Expand Up @@ -363,6 +365,16 @@ var _ = Describe("MemoryDump", func() {
vmexport.SetHTTPClientCreator(func(*http.Transport, bool) *http.Client {
return server.Client()
})
vmexport.SetPortForwarder(func(client kubecli.KubevirtClient, pod k8sv1.Pod, namespace string, ports []string, stopChan, readyChan chan struct{}, portChan chan uint16) error {
readyChan <- struct{}{}
portChan <- uint16(5432)
return nil
})
})

AfterEach(func() {
vmexport.SetDefaultPortForwarder()
vmexport.SetDefaultHTTPClientCreator()
})

It("should get memory dump and call download memory dump", func() {
Expand Down Expand Up @@ -401,6 +413,36 @@ var _ = Describe("MemoryDump", func() {
Expect(cmd.Execute()).To(Succeed())
})

DescribeTable("should call download memory dump with port-forward", func(commandAndArgs []string) {
vmexport.HandleHTTPRequest = func(client kubecli.KubevirtClient, vmexport *exportv1.VirtualMachineExport, downloadUrl string, insecure bool, exportURL string, headers map[string]string) (*http.Response, error) {
Expect(downloadUrl).To(Equal("https://127.0.0.1:5432"))
resp := http.Response{
StatusCode: http.StatusOK,
Body: io.NopCloser(strings.NewReader("data")),
}
return &resp, nil
}
memorydump.WaitMemoryDumpComplete = waitForMemoryDumpDefault
vme := utils.VMExportSpecPVC(vmexportName, k8smetav1.NamespaceDefault, claimName, secretName)
vme.Status = utils.GetVMEStatus([]exportv1.VirtualMachineExportVolume{
{
Name: claimName,
Formats: utils.GetExportVolumeFormat(server.URL, exportv1.KubeVirtGz),
},
}, secretName)
vme.Status.Links.Internal = vme.Status.Links.External
utils.HandleSecretGet(coreClient, secretName)
utils.HandleVMExportCreate(vmExportClient, vme)
utils.HandleServiceGet(coreClient, fmt.Sprintf("virt-export-%s", vme.Name), 443)
utils.HandlePodList(coreClient, fmt.Sprintf("virt-export-pod-%s", vme.Name))
cmd := clientcmd.NewVirtctlCommand(commandAndArgs...)
Expect(cmd.Execute()).To(Succeed())
},
Entry("with default port-forward", []string{"memory-dump", "download", "testvm", outputFileFlag, "--port-forward"}),
Entry("with port-forward specifying local port", []string{"memory-dump", "download", "testvm", outputFileFlag, "--port-forward", "--local-port", "5432"}),
Entry("with port-forward specifying default number on local port", []string{"memory-dump", "download", "testvm", outputFileFlag, "--port-forward", "--local-port", "0"}),
)

It("should fail download memory dump if not completed succesfully", func() {
memorydump.WaitMemoryDumpComplete = waitForMemoryDumpErr

Expand Down
119 changes: 78 additions & 41 deletions pkg/virtctl/vmexport/vmexport.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -77,6 +77,7 @@ const (
SERVICE_URL_FLAG = "--service-url"
INCLUDE_SECRET_FLAG = "--include-secret"
PORT_FORWARD_FLAG = "--port-forward"
LOCAL_PORT_FLAG = "--local-port"

// Possible output format for manifests
OUTPUT_FORMAT_JSON = "json"
Expand Down Expand Up @@ -126,7 +127,8 @@ var (
shouldCreate bool
includeSecret bool
exportManifest bool
portForward string
portForward bool
localPort string
serviceUrl string
volumeName string
ttl string
Expand All @@ -137,7 +139,7 @@ type exportFunc func(client kubecli.KubevirtClient, vmeInfo *VMExportInfo) error

type HTTPClientCreator func(*http.Transport, bool) *http.Client

type PortForwardFunc func(client kubecli.KubevirtClient, pod k8sv1.Pod, namespace string, ports []string, stopChan, readyChan chan struct{}) error
type PortForwardFunc func(client kubecli.KubevirtClient, pod k8sv1.Pod, namespace string, ports []string, stopChan, readyChan chan struct{}, portChan chan uint16) error

type exportCompleteFunc func(kubecli.KubevirtClient, *VMExportInfo, time.Duration, time.Duration) error

Expand All @@ -151,7 +153,8 @@ type VMExportInfo struct {
KeepVme bool
IncludeSecret bool
ExportManifest bool
PortForward string
PortForward bool
LocalPort string
OutputFile string
OutputWriter io.Writer
VolumeName string
Expand Down Expand Up @@ -217,7 +220,7 @@ func usage() string {
{{ProgramName}} vmexport download vm1-export --volume=volume1 --output=disk.img.gz
# Download a volume as before but through local port 5410
{{ProgramName}} vmexport download vm1-export --volume=volume1 --output=disk.img.gz --port-forward=5410
{{ProgramName}} vmexport download vm1-export --volume=volume1 --output=disk.img.gz --port-forward --local-port=5410
# Create a VirtualMachineExport and download the requested volume from it
{{ProgramName}} vmexport download vm1-export --vm=vm1 --volume=volume1 --output=disk.img.gz
Expand Down Expand Up @@ -254,7 +257,8 @@ func NewVirtualMachineExportCommand(clientConfig clientcmd.ClientConfig) *cobra.
cmd.Flags().StringVar(&ttl, "ttl", "", "The time after the export was created that it is eligible to be automatically deleted, defaults to 2 hours by the server side if not specified")
cmd.Flags().StringVar(&manifestOutputFormat, "manifest-output-format", "", "Manifest output format, defaults to Yaml. Valid options are yaml or json")
cmd.Flags().StringVar(&serviceUrl, "service-url", "", "Specify service url to use in the returned manifest, instead of the external URL in the Virtual Machine export status. This is useful for NodePorts or if you don't have an external URL configured")
cmd.Flags().StringVar(&portForward, "port-forward", "", "Configures port-forwarding on the specified port. Useful to download without proper ingress/route configuration")
cmd.Flags().BoolVar(&portForward, "port-forward", false, "Configures port-forwarding on a random port. Useful to download without proper ingress/route configuration")
cmd.Flags().StringVar(&localPort, "local-port", "0", "Defines the specific port to be used in port-forward.")
cmd.Flags().BoolVar(&includeSecret, "include-secret", false, "When used with manifest and set to true include a secret that contains proper headers for CDI to import using the manifest")
cmd.Flags().BoolVar(&exportManifest, "manifest", false, "Instead of downloading a volume, retrieve the VM manifest")
cmd.SetUsageTemplate(templates.UsageTemplate())
Expand Down Expand Up @@ -351,12 +355,13 @@ func (c *command) initVMExportInfo(vmeInfo *VMExportInfo) error {
vmeInfo.OutputFormat = manifestOutputFormat
vmeInfo.IncludeSecret = includeSecret
vmeInfo.ExportManifest = exportManifest
if portForward != "" {
if portForward {
vmeInfo.PortForward = portForward
vmeInfo.Insecure = true
// Defaults to 0, which will be replaced by a random available port
vmeInfo.LocalPort = localPort
if vmeInfo.ServiceURL == "" {
// Defaulting to localhost
vmeInfo.ServiceURL = fmt.Sprintf("127.0.0.1:%s", portForward)
vmeInfo.ServiceURL = fmt.Sprintf("127.0.0.1:%s", vmeInfo.LocalPort)
}
}
vmeInfo.TTL = metav1.Duration{}
Expand Down Expand Up @@ -451,7 +456,7 @@ func DownloadVirtualMachineExport(client kubecli.KubevirtClient, vmeInfo *VMExpo
defer DeleteVirtualMachineExport(client, vmeInfo)
}

if vmeInfo.PortForward != "" {
if vmeInfo.PortForward {
stopChan, err := setupPortForward(client, vmeInfo)
if err != nil {
return err
Expand Down Expand Up @@ -647,10 +652,15 @@ func GetManifestUrlsFromVirtualMachineExport(vmexport *exportv1.VirtualMachineEx
func waitForVirtualMachineExport(client kubecli.KubevirtClient, vmeInfo *VMExportInfo, interval, timeout time.Duration) error {
err := wait.PollImmediate(interval, timeout, func() (bool, error) {
vmexport, err := getVirtualMachineExport(client, vmeInfo)
if err != nil || vmexport == nil {
if err != nil {
return false, err
}

if vmexport == nil {
fmt.Printf("couldn't get VM Export %s, waiting for it to be created...\n", vmeInfo.Name)
return false, nil
}

if vmexport.Status == nil {
return false, nil
}
Expand Down Expand Up @@ -838,9 +848,12 @@ func handleCreateFlags() error {
if keepVme {
return fmt.Errorf(ErrIncompatibleFlag, KEEP_FLAG, CREATE)
}
if portForward != "" {
if portForward {
return fmt.Errorf(ErrIncompatibleFlag, PORT_FORWARD_FLAG, CREATE)
}
if localPort != "0" {
return fmt.Errorf(ErrIncompatibleFlag, LOCAL_PORT_FLAG, CREATE)
}
if serviceUrl != "" {
return fmt.Errorf(ErrIncompatibleFlag, SERVICE_URL_FLAG, CREATE)
}
Expand All @@ -866,9 +879,12 @@ func handleDeleteFlags() error {
if keepVme {
return fmt.Errorf(ErrIncompatibleFlag, KEEP_FLAG, DELETE)
}
if portForward != "" {
if portForward {
return fmt.Errorf(ErrIncompatibleFlag, PORT_FORWARD_FLAG, DELETE)
}
if localPort != "0" {
return fmt.Errorf(ErrIncompatibleFlag, LOCAL_PORT_FLAG, DELETE)
}
if serviceUrl != "" {
return fmt.Errorf(ErrIncompatibleFlag, SERVICE_URL_FLAG, DELETE)
}
Expand All @@ -883,10 +899,10 @@ func handleDownloadFlags() error {
shouldCreate = true
}

if portForward != "" {
port, err := strconv.Atoi(portForward)
if portForward {
port, err := strconv.Atoi(localPort)
if err != nil || port < 0 || port > 65535 {
return fmt.Errorf(ErrInvalidValue, PORT_FORWARD_FLAG, "valid port numbers")
return fmt.Errorf(ErrInvalidValue, LOCAL_PORT_FLAG, "valid port numbers")
}
}

Expand Down Expand Up @@ -971,30 +987,6 @@ func waitForExportServiceToBeReady(client kubecli.KubevirtClient, vmeInfo *VMExp
return service, err
}

// runPortForward is the actual function that runs the port-forward. Meant to be run concurrently
func runPortForward(client kubecli.KubevirtClient, pod k8sv1.Pod, namespace string, ports []string, stopChan, readyChan chan struct{}) error {
// Create a port forwarding request
req := client.CoreV1().RESTClient().Post().
Resource("pods").
Name(pod.Name).
Namespace(namespace).
SubResource("portforward")

// Set up the port forwarding options
transport, upgrader, err := spdy.RoundTripperFor(client.Config())
if err != nil {
log.Fatalf("Failed to set up transport: %v", err)
}
dialer := spdy.NewDialer(upgrader, &http.Client{Transport: transport}, "POST", req.URL())

// Start port-forwarding
fw, err := portforward.New(dialer, ports, stopChan, readyChan, os.Stdout, os.Stderr)
if err != nil {
log.Fatalf("Failed to setup port forward: %v", err)
}
return fw.ForwardPorts()
}

// setupPortForward runs a port-forward after initializing all required arguments
func setupPortForward(client kubecli.KubevirtClient, vmeInfo *VMExportInfo) (chan struct{}, error) {
// Wait for the vmexport object to be ready
Expand All @@ -1018,21 +1010,66 @@ func setupPortForward(client kubecli.KubevirtClient, vmeInfo *VMExportInfo) (cha
}

// Set up the port forwarding ports
ports, err := translateServicePortToTargetPort(vmeInfo.PortForward, "443", *service, podList.Items[0])
ports, err := translateServicePortToTargetPort(vmeInfo.LocalPort, "443", *service, podList.Items[0])
if err != nil {
return nil, err
}

stopChan := make(chan struct{}, 1)
readyChan := make(chan struct{})
go startPortForward(client, podList.Items[0], vmeInfo.Namespace, ports, stopChan, readyChan)
portChan := make(chan uint16)
go startPortForward(client, podList.Items[0], vmeInfo.Namespace, ports, stopChan, readyChan, portChan)

// Wait for the port forwarding to be ready
select {
case <-readyChan:
fmt.Println("Port forwarding is ready.")
// Using 0 allows listening on a random available port.
// Now we need to find out which port was used
if vmeInfo.LocalPort == "0" {
localPort := <-portChan
close(portChan)
vmeInfo.ServiceURL = fmt.Sprintf("127.0.0.1:%d", localPort)
}
case <-time.After(30 * time.Second):
return nil, fmt.Errorf("Timeout waiting for port forwarding to be ready.")
}
return stopChan, nil
}

// runPortForward is the actual function that runs the port-forward. Meant to be run concurrently
func runPortForward(client kubecli.KubevirtClient, pod k8sv1.Pod, namespace string, ports []string, stopChan, readyChan chan struct{}, portChan chan uint16) error {
// Create a port forwarding request
req := client.CoreV1().RESTClient().Post().
Resource("pods").
Name(pod.Name).
Namespace(namespace).
SubResource("portforward")

// Set up the port forwarding options
transport, upgrader, err := spdy.RoundTripperFor(client.Config())
if err != nil {
log.Fatalf("Failed to set up transport: %v", err)
}
dialer := spdy.NewDialer(upgrader, &http.Client{Transport: transport}, "POST", req.URL())

// Start port-forwarding
fw, err := portforward.New(dialer, ports, stopChan, readyChan, os.Stdout, os.Stderr)
if err != nil {
log.Fatalf("Failed to setup port forward: %v", err)
}
slicedPorts := strings.Split(ports[0], ":")
if len(slicedPorts) == 2 && slicedPorts[0] == "0" {
// If the local port is 0, then the port-forwarder will pick a random available port.
// We need to send this port number back to the caller.
go func() {
<-readyChan
forwardedPorts, err := fw.GetPorts()
if err != nil {
log.Fatalf("Failed to get forwarded ports: %v", err)
}
portChan <- forwardedPorts[0].Local
}()
}
return fw.ForwardPorts()
}

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