Enable remote debugging with delve

[mauriciopoppe]

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

/kind documentation

What this PR does / why we need it:

Enables remote debugging of the pd-csi-driver controller running on a cluster inside a container,
summary of changes:

• New Dockerfile.debug file, this file used only in linux nodes includes the delve binary and the source code of the app
• New overlay noauth-dev, the overlay starts the PD CSI driver controller with delve in headless mode accepting connections in the port 2345
• New debug multiarch target in the Makefile, to build the binaries in debug mode
• Docs

Steps to deploy the binaries:

• run this target: make build-and-push-multi-arch-dev
• delete and deploy the driver with the overlay:

./deploy/kubernetes/delete-driver.sh &&  GCE_PD_DRIVER_VERSION=noauth-dev ./deploy/kubernetes/deploy-driver.sh

• once the controller starts enable portforwarding on port 2345
• connect to the delve server and issue commands

dlv connect localhost:2345
Type 'help' for list of commands.
(dlv) clear
Command failed: not enough arguments
(dlv) clearall
Breakpoint 1 cleared at 0x159bbd2 for sigs.k8s.io/gcp-compute-persistent-disk-csi-driver/pkg/gce-pd-csi-driver.(*GCEControllerServer).ListVolumes() ./pkg/gce-pd-csi-driver/controller.go:509
(dlv) break pkg/gce-pd-csi-driver/controller.go:509
Breakpoint 2 set at 0x159bbd2 for sigs.k8s.io/gcp-compute-persistent-disk-csi-driver/pkg/gce-pd-csi-driver.(*GCEControllerServer).ListVolumes() ./pkg/gce-pd-csi-driver/controller.go:509
(dlv) l
> sigs.k8s.io/gcp-compute-persistent-disk-csi-driver/pkg/gce-pd-csi-driver.(*GCEControllerServer).ListVolumes() ./pkg/gce-pd-csi-driver/controller.go:509 (hits goroutine(49):1 total:1) (PC: 0x159bbd2)
Warning: debugging optimized function
Warning: listing may not match stale executable
   504:         }
   505: }
   506:
   507: func (gceCS *GCEControllerServer) ListVolumes(ctx context.Context, req *csi.ListVolumesRequest) (*csi.ListVolumesResponse, error) {
   508:         // https://cloud.google.com/compute/docs/reference/beta/disks/list
=> 509:         if req.MaxEntries < 0 {
   510:                 return nil, status.Error(codes.InvalidArgument, fmt.Sprintf(
   511:                         "ListVolumes got max entries request %v. GCE only supports values between 0-500", req.MaxEntries))
   512:         }
   513:         var maxEntries int64 = int64(req.MaxEntries)
   514:         if maxEntries > 500 {
(dlv) p req
*github.com/container-storage-interface/spec/lib/go/csi.ListVolumesRequest {
        MaxEntries: 0,
        StartingToken: "",
        XXX_NoUnkeyedLiteral: struct {} {},
        XXX_unrecognized: []uint8 len: 0, cap: 0, nil,
        XXX_sizecache: 0,}

Does this PR introduce a user-facing change?:

NONE

[k8s-ci-robot]

Hi @mauriciopoppe. Thanks for your PR.

I'm waiting for a kubernetes-sigs 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.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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[mattcary]

/ok-to-test
/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

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

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• OWNERS [mattcary]

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[mattcary]

/hold

Oops, didn't see it was still a draft.

[mauriciopoppe]

@mattcary I think this is ready

[mattcary]

Very cool!

Just a few nits.

[mattcary]

/lgtm

[mauriciopoppe]

/hold cancel