reporter panics on k8s container image scan

[czunker]

Describe the bug
The cnspec CLI reporter panics when scanning k8s container images.

I came across this inside a minikube cluster, while testing mondoohq/mondoo-operator#873.

But I could also reproduce it outside the cluster:

Scanned 15 assets

Alpine Linux v3.18
    B index.docker.io/mondoo/cnspec@c4fcf2666941

Distroless
    C quay.io/jetstack/cert-manager-cainjector@7c65d8478484
    C quay.io/jetstack/cert-manager-controller@63a7aa17a1b1
    C quay.io/jetstack/cert-manager-webhook@c5644d09c6cf
    C registry.k8s.io/etcd@51eae8381dcb
    C registry.k8s.io/kube-apiserver@697cd88d94f7
    C registry.k8s.io/kube-controller-manager@6286e500782a
    C registry.k8s.io/kube-proxy@4bcb707da989
    C registry.k8s.io/kube-scheduler@5897d7a97d23
    C registry.k8s.io/metrics-server/metrics-server@ee4304963fb0

Red Hat Enterprise Linux 8.8 (Ootpa)
    C index.docker.io/calico/node@8e34517775f3

scratch
    U gcr.io/k8s-minikube/storage-provisioner@18eb69d1418e
    U index.docker.io/calico/cni@3be3c67ddba1
    U index.docker.io/calico/kube-controllers@01ce29ea8f2b
    U registry.k8s.io/coredns/coredns@a0ead06651cf

Summary
=======

Score Distribution		Asset Distribution
------------------		------------------
A   0 assets      		scratch                                4
B   1 assets      		Red Hat Enterprise Linux 8.8 (Ootpa)   1
C  10 assets      		Alpine Linux v3.18                     1
D   0 assets      		Distroless                             9
F   0 assets
U   4 assets

panic: runtime error: index out of range [1] with length 0

goroutine 1 [running]:
go.mondoo.com/cnspec/cli/reporter.(*defaultReporter).printSummary(0xc0051e9a98, {0xc001ae03c0, 0xf, 0x0?})
	/home/runner/_work/cnspec/cnspec/cli/reporter/print_compact.go:174 +0xe45
go.mondoo.com/cnspec/cli/reporter.(*defaultReporter).print(0xc0051e9a98)
	/home/runner/_work/cnspec/cnspec/cli/reporter/print_compact.go:71 +0x24f
go.mondoo.com/cnspec/cli/reporter.(*Reporter).Print(0xa096e63?, 0x7?, {0xb2839c0?, 0xc0000f0038?})
	/home/runner/_work/cnspec/cnspec/cli/reporter/reporter.go:53 +0x12f
go.mondoo.com/cnspec/apps/cnspec/cmd.printReports(0xa093bb6?, 0xc001b48780, 0x9b520c0?)
	/home/runner/_work/cnspec/cnspec/apps/cnspec/cmd/scan.go:715 +0xa5
go.mondoo.com/cnspec/apps/cnspec/cmd.glob..func22(0x0?, {0xc003213440, 0x0, 0x4}, 0x0?, 0x0?)
	/home/runner/_work/cnspec/cnspec/apps/cnspec/cmd/scan.go:417 +0x1a8
go.mondoo.com/cnquery/apps/cnquery/cmd/builder.kubernetesProviderCmd.func1(0x0?, {0xc003213440?, 0x0?, 0x0?})
	/home/runner/go/pkg/mod/go.mondoo.com/[email protected]/apps/cnquery/cmd/builder/builder.go:316 +0x28
go.mondoo.com/cnquery/apps/cnquery/cmd/builder/common.KubernetesProviderCmd.func2(0xc003066a00?, {0xc003213440?, 0x4?, 0xa09059b?})
	/home/runner/go/pkg/mod/go.mondoo.com/[email protected]/apps/cnquery/cmd/builder/common/common.go:295 +0x75
github.com/spf13/cobra.(*Command).execute(0xc003090000, {0xc003213400, 0x4, 0x4})
	/home/runner/go/pkg/mod/github.com/spf13/[email protected]/command.go:944 +0x863
github.com/spf13/cobra.(*Command).ExecuteC(0x102d82e0)
	/home/runner/go/pkg/mod/github.com/spf13/[email protected]/command.go:1068 +0x3a5
github.com/spf13/cobra.(*Command).Execute(...)
	/home/runner/go/pkg/mod/github.com/spf13/[email protected]/command.go:992
go.mondoo.com/cnspec/apps/cnspec/cmd.Execute()
	/home/runner/_work/cnspec/cnspec/apps/cnspec/cmd/root.go:79 +0x1a
main.main()
	/home/runner/_work/cnspec/cnspec/apps/cnspec/cnspec.go:6 +0xf

It does not always happen. I didn't happen when scanning against prod, but against edge.

To Reproduce
Steps to reproduce the behavior:

1. Command: cnspec scan k8s --discover container-images --config ~/workspace/mondoo/sa-edge-default.json
2. Note the error

Expected behavior
I'd expect no panic.

Desktop (please complete the following information):

• cnspec 8.28.4 (2fbca64, 2023-09-20T10:27:51Z)

Additional context
I'm not sure what's the difference is between edge and prod. Perhaps I've different policies active.

I didn't check v9 so far.

[czunker]

The same worked with v9:

cnspec scan k8s --discover container-images --config ~/workspace/mondoo/sa-edge-default.json
...
Scanned 15 assets

Alpine Linux v3.18
    B index.docker.io/mondoo/cnspec@17c97d6e602b

Distroless
    C quay.io/jetstack/cert-manager-cainjector@da7e239ee264
    C quay.io/jetstack/cert-manager-controller@2642e7f41545
    C quay.io/jetstack/cert-manager-webhook@a3205d026246
    C registry.k8s.io/etcd@8ae03c7bbd43
    C registry.k8s.io/kube-apiserver@dcf39b4579f8
    C registry.k8s.io/kube-controller-manager@c4765f949306
    C registry.k8s.io/kube-proxy@ce9abe867450
    C registry.k8s.io/kube-scheduler@9c58009453cf
    C registry.k8s.io/metrics-server/metrics-server@9f50dd170c11

Red Hat Enterprise Linux 8.8 (Ootpa)
    C index.docker.io/calico/node@9459d1b28319

scratch
    U gcr.io/k8s-minikube/storage-provisioner@c4c05d6ad6c0
    U index.docker.io/calico/cni@86779fab56f3
    U index.docker.io/calico/kube-controllers@2c5526ad8cd6
    U registry.k8s.io/coredns/coredns@be7652ce0b43

Summary
=======

Score Distribution		Asset Distribution
------------------		------------------
A   0 assets      		scratch                                4
B   1 assets      		Red Hat Enterprise Linux 8.8 (Ootpa)   1
C  10 assets      		Alpine Linux v3.18                     1
D   0 assets      		Distroless                             9
F   0 assets
U   4 assets

See more scan results and asset relationships on the Mondoo Console: https://edge.console.mondoo.com/space/inventory?spaceId=elastic-payne-456551

I used latest main for the test.