Add another client per API that can communicate with a custom named pipe

[mauriciopoppe]

What type of PR is this?

/kind feature

What this PR does / why we need it:

There are two scenarios that we might see while deploying the CSI proxy:

• PD CSI driver imports the v1 CSI Proxy client, the node has the beta CSI Proxy server
• PD CSI driver imports the v1 CSI Proxy client, the node has the v1 CSI Proxy server

Instead of handling multiple imports in PD CSI driver we can just use the v1 client with additional startup code to identify which of these cases should attempt to solve.

This PR adds another way to initialize a client by sending a named pipe, the idea is that the user of the client can import the v1 client and still be able to call the v1beta named pipes for compatibility

The client is:

func NewClientWithPipePath(pipePath string) (*Client, error)

The consumers of the client should send the pipePath they want to use, for example GCE PD CSI driver is using the following:

import (
	csiproxyclient "github.com/kubernetes-csi/csi-proxy/client"
	"github.com/kubernetes-csi/csi-proxy/client/apiversion"

	diskapi "github.com/kubernetes-csi/csi-proxy/client/api/disk/v1"
	diskclient "github.com/kubernetes-csi/csi-proxy/client/groups/disk/v1"
)

func getDiskClient() (*diskclient.Client, error) {
	var err error
	versionv1beta2 := apiversion.NewVersionOrPanic("v1beta2")
	diskAPIVersions := []apiversion.Version{diskClient.Version /* v1 */, versionv1beta2}

	// attempt to connect to one of the clients in order
	for _, apiVersion := range diskAPIVersions {
		pipePath := csiproxyclient.PipePath(diskclient.GroupName, apiVersion)
		klog.V(4).Infof("Attempting to connect to csi-proxy diskapi at path=%s", pipePath)
		diskClient, err := diskclient.NewClientWithPipePath(pipePath)
		if err == nil {
			klog.V(4).Infof("Connected to csi-proxy diskapi at path=%s", pipePath)
			return diskClient, nil
		}
		klog.V(4).Infof("Connection to csi-proxy diskapi at path=%s failed with error %v, might retry with a different version", pipePath, err)
	}
	return nil, fmt.Errorf("Couldn't connect to any csi-proxy diskapi server, last error %v", err)
}

func NewCSIProxyMounter() (*CSIProxyMounter, error) {
	diskClient, err := getDiskClient()
	if err != nil {
		return nil, err
	}

	fsClient, err := fsclient.NewClient()
	if err != nil {
		return nil, err
	}
	volumeClient, err := volumeclient.NewClient()
	if err != nil {
		return nil, err
	}
	return &CSIProxyMounter{
		FsClient:     fsClient,
		DiskClient:   diskClient,
		VolumeClient: volumeClient,
	}, nil
}

In my cluster I have CSI Proxy server v0.2, I've deployed GCE PD CSI driver with the v1 client (this change) and it could successfully avoid connecting to the v1 api because it doesn't exist, the logs:

I0407 05:51:58.024148    4288 safe-mounter_windows.go:63] Attempting to connect to csi-proxy diskapi at path=\\.\\pipe\\csi-proxy-disk-v1
I0407 05:51:58.024148    4288 safe-mounter_windows.go:69] Connection to csi-proxy diskapi at path=\\.\\pipe\\csi-proxy-disk-v1 failed with error=open \\.\\pipe\\csi-proxy-disk-v1: The system cannot find the file specified., might retry with a different version
I0407 05:51:58.025117    4288 safe-mounter_windows.go:63] Attempting to connect to csi-proxy diskapi at path=\\.\\pipe\\csi-proxy-disk-v1beta2
I0407 05:51:58.025117    4288 safe-mounter_windows.go:66] Connected to csi-proxy diskapi at path=\\.\\pipe\\csi-proxy-disk-v1beta2
I0407 05:51:58.025117    4288 safe-mounter_windows.go:81] Attempting to connect to csi-proxy fsapi at path=\\.\\pipe\\csi-proxy-filesystem-v1
I0407 05:51:58.025117    4288 safe-mounter_windows.go:87] Connection to csi-proxy fsapi at path=\\.\\pipe\\csi-proxy-filesystem-v1 failed with error=open \\.\\pipe\\csi-proxy-filesystem-v1: The system cannot find the file specified., might retry with a different version
I0407 05:51:58.025117    4288 safe-mounter_windows.go:81] Attempting to connect to csi-proxy fsapi at path=\\.\\pipe\\csi-proxy-filesystem-v1beta1
I0407 05:51:58.026099    4288 safe-mounter_windows.go:84] Connected to csi-proxy fsapi at path=\\.\\pipe\\csi-proxy-filesystem-v1beta1
I0407 05:51:58.026099    4288 safe-mounter_windows.go:99] Attempting to connect to csi-proxy volumeapi at path=\\.\\pipe\\csi-proxy-volume-v1
I0407 05:51:58.026099    4288 safe-mounter_windows.go:105] Connection to csi-proxy volumeapi at path=\\.\\pipe\\csi-proxy-volume-v1 failed with error=open \\.\\pipe\\csi-proxy-volume-v1: The system cannot find the file specified., might retry with a different version
I0407 05:51:58.026099    4288 safe-mounter_windows.go:99] Attempting to connect to csi-proxy volumeapi at path=\\.\\pipe\\csi-proxy-volume-v1beta1
I0407 05:51:58.026099    4288 safe-mounter_windows.go:102] Connected to csi-proxy volumeapi at path=\\.\\pipe\\csi-proxy-volume-v1beta1

Edit:

Even though I could connect to the v1beta API using the v1 client I couldn't send a message to it, the error I got was:

gce-pd-driver I0407 19:48:16.583101    8696 utils.go:60] /csi.v1.Node/NodeUnstageVolume called with request: volume_id:"projects/UNSPECIFIED/zones/us-central1-b/disks/pvc-1190e7da-72f1-480f-8c9d-95209b061660" staging_target_path:"\\var\\lib\\kubelet\\pl
 ugins\\kubernetes.io\\csi\\volumeDevices\\staging\\pvc-1190e7da-72f1-480f-8c9d-95209b061660"
 gce-pd-driver E0407 19:48:16.584111    8696 utils.go:63] /csi.v1.Node/NodeUnstageVolume returned with error: rpc error: code = Internal desc = NodeUnstageVolume failed: rpc error: code = Unimplemented desc = unknown service v1.Filesystem

In PD CSI we are falling back to using both APIs at the same time, in any case, the check with winio.Dial works :)

Does this PR introduce a user-facing change?:

NONE

/assign @jingxu97

[k8s-ci-robot]

Hi @mauriciopoppe. Thanks for your PR.

I'm waiting for a kubernetes-csi member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[mauriciopoppe]

/assign @ddebroy

[ddebroy]

/retest

[ddebroy]

This is super cool!
/lgtm

[ddebroy]

Will approve shortly as soon as the pull-kubernetes-csi-csi-proxy reports

[jingxu97]

wondering what is the difference between winio.DialPipe and the following grpc.Dial?

[mauriciopoppe]

I read the first test in https://github.com/microsoft/go-winio/blob/master/pipe_test.go, grpc.Dial creates connections in the background unless WithBlock() is also sent as an option (which I also tried but got stuck in the v1 request)

[ddebroy]

/lgtm

[jingxu97]

/ok-to-test

[mauriciopoppe]

/retest

[mauriciopoppe]

/retest

[ddebroy]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ddebroy, mauriciopoppe

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