2. Kubernetes Test Cases and Requirements Traceability

2.1. Introduction

All of the requirements for RC2 have been defined in the Reference Model (RM) and Reference Architecture (RA2). The scope of this chapter is to identify and list down test cases based on these requirements. Users of this chapter will be able to use it to determine which test cases they must run in order to test compliance with the requirements. This will enable traceability between the test cases and requirements. They should be able to clearly see which requirements are covered by which tests and the mapping from a specific test result (pass or fail) to a requirement. Each requirement may have one or more test case associated with it.

2.1.1. Goals

  • Clear mapping between requirements and test cases

  • Provide a stable set of point-in-time requirements and tests to achieve conformance

  • Enable clear traceability of the coverage of requirements across consecutive releases of this document

  • Clickable links from test cases to requirements

  • One or more tests for every MUST requirement

  • A set of test cases to serve as a template for Anuket Assured

2.1.2. Non-Goals

  • Defining any requirements

  • Providing coverage for non-testable requirements

2.1.3. Definitions

must: Test Cases that are marked as must are considered mandatory and must pass successfully

should: Test Cases that are marked as should are expected to be fulfilled by the cloud infrastructure but it is up to each service provider whether to accept a cloud infrastructure that is not fulfilling any of these requirements. The same applies to should not.

may: Test cases that are marked as may are considered optional. The same applies to may not.

2.2. Traceability Matrix

2.2.1. Kubernetes API testing

The primary objectives of the e2e tests are to ensure a consistent and reliable behavior of the Kubernetes code base, and to catch hard-to-test bugs before users do, when unit and integration tests are insufficient. They are partially selected for the Software Conformance Certification program run by the Kubernetes community (under the aegis of the CNCF).

Anuket shares the same goal to give end users the confidence that when they use a certified product they can rely on a high level of common functionality. Then Anuket RC2 starts with the test list defined by K8s Conformance which is expected to grow according to the ongoing requirement traceability.

End-to-End Testing basically asks for focus and skip regexes to select or to exclude single tests:

The Reference Conformance suites must be stable and executed on real deployments. Then all the following labels are defacto skipped in End-to-End Testing:

  • alpha

  • Disruptive

  • Flaky

It’s worth mentioning that no alpha or Flaky test can be included in Conformance as per the rules.

2.2.1.1. Conformance

It must be noted that the default K8s Conformance testing is disruptive thus Anuket RC2 rather picks non-disruptive-conformance testing as defined by Sonobuoy.

focus: Conformance

skip:

  • [Disruptive]

  • NoExecuteTaintManager

2.2.1.2. API Machinery Testing

focus: [sig-api-machinery]

skip:

  • [alpha]

  • [Disruptive]

  • [Flaky]

  • [Feature:CrossNamespacePodAffinity]

  • [Feature:CustomResourceValidationExpressions]

  • [Feature:StorageVersionAPI]

See API Machinery Special Interest Group and API and Feature Testing requirements for more details.

2.2.1.3. Apps Testing

focus: [sig-apps]

skip:

  • [alpha]

  • [Disruptive]

  • [Flaky]

  • [Feature:DaemonSetUpdateSurge]

  • [Feature:IndexedJob]

  • [Feature:StatefulSet]

  • [Feature:StatefulSetAutoDeletePVC]

  • [Feature:StatefulUpgrade]

  • [Feature:SuspendJob]

See Apps Special Interest Group and API and Feature Testing requirements for more details.

2.2.1.4. Auth Testing

focus: [sig-auth]

skip:

  • [alpha]

  • [Disruptive]

  • [Flaky]

  • [Feature:BoundServiceAccountTokenVolume]

  • [Feature:PodSecurityPolicy]

See Auth Special Interest Group and API and Feature Testing requirements for more details.

2.2.1.5. Cluster Lifecycle Testing

focus: [sig-cluster-lifecycle]

skip:

  • [alpha]

  • [Disruptive]

  • [Flaky]

See Cluster Lifecycle Special Interest Group and API and Feature Testing requirements for more details.

2.2.1.6. Instrumentation Testing

focus: [sig-instrumentation]

skip:

  • [alpha]

  • [Disruptive]

  • [Flaky]

  • [Feature:Elasticsearch]

  • [Feature:StackdriverAcceleratorMonitoring]

  • [Feature:StackdriverCustomMetrics]

  • [Feature:StackdriverExternalMetrics]

  • [Feature:StackdriverMetadataAgent]

  • [Feature:StackdriverMonitoring]

See Instrumentation Special Interest Group and API and Feature Testing requirements for more details.

2.2.1.7. Network Testing

The regexes load.balancer, LoadBalancer and Network.should.set.TCP.CLOSE_WAIT.timeout are currently skipped because they haven’t been covered successfully neither by sig-release-1.23-blocking nor by Anuket RC2 verification

Please note that a couple of tests must be skipped by name below as they are no appropriate labels.

focus: [sig-network]

skip:

  • [alpha]

  • [Disruptive]

  • [Flaky]

  • [Feature:Example]

  • [Feature:Ingress]

  • [Feature:IPv6DualStack]

  • [Feature:kubemci]

  • [Feature:KubeProxyDaemonSetMigration]

  • [Feature:KubeProxyDaemonSetUpgrade]

  • [Feature:NEG]

  • [Feature:Networking-IPv6]

  • [Feature:NetworkPolicy]

  • [Feature:PerformanceDNS]

  • [Feature:SCTP]

  • [Feature:SCTPConnectivity]

  • DNS configMap nameserver

  • load.balancer

  • LoadBalancer

  • Network.should.set.TCP.CLOSE_WAIT.timeout

See Network Special Interest Group and API and Feature Testing requirements.

2.2.1.8. Node Testing

focus: [sig-node]

skip:

  • [alpha]

  • [Disruptive]

  • [Flaky]

  • [Feature:ExperimentalResourceUsageTracking]

  • [Feature:GRPCContainerProbe]

  • [Feature:GPUUpgrade]

  • [Feature:PodGarbageCollector]

  • [Feature:RegularResourceUsageTracking]

  • [NodeFeature:DownwardAPIHugePages]

  • [NodeFeature:RuntimeHandler]

See Node Special Interest Group and API and Feature Testing requirements.

2.2.1.9. Scheduling Testing

focus: [sig-scheduling]

skip:

  • [alpha]

  • [Disruptive]

  • [Flaky]

  • [Feature:GPUDevicePlugin]

  • [Feature:Recreate]

See Scheduling Special Interest Group and API and Feature Testing requirements.

2.2.1.10. Storage Testing

It should be noted that all in-tree driver testing, [Driver:+], is skipped. Conforming to the upstream gate, all PersistentVolumes NFS testing is also skipped. The following exclusions are about the deprecated in-tree GitRepo volume type:

  • should provision storage with different parameters

  • should not cause race condition when used for git_repo

Please note that a couple of tests must be skipped by name below as they are no appropriate labels.

focus: [sig-storage]

skip:

  • [alpha]

  • [Disruptive]

  • [Flaky]

  • [Driver:+]

  • [Feature:ExpandInUsePersistentVolumes]

  • [Feature:Flexvolumes]

  • [Feature:GKELocalSSD]

  • [Feature:VolumeSnapshotDataSource]

  • [Feature:Flexvolumes]

  • [Feature:vsphere]

  • [Feature:Volumes]

  • [Feature:Windows]

  • [NodeFeature:EphemeralStorage]

  • PersistentVolumes.NFS

  • should provision storage with different parameters

  • should not cause race condition when used for git_repo

See Storage Special Interest Group and API and Feature Testing requirements.

2.2.2. Kubernetes API benchmarking

Rally is a tool and framework that performs Kubernetes API benchmarking.

Functest Kubernetes Benchmarking proposed a Rally-based test case, xrally_kubernetes_full, which iterates 10 times the mainline xrally-kubernetes scenarios.

At the time of writing, no KPI is defined in Kubernetes based Reference Architecture which would have asked for an update of the default SLA (maximum failure rate of 0%) proposed in Functest Kubernetes Benchmarking

Functest xrally_kubernetes_full:

Table 2.1 Kubernetes API benchmarking

Scenarios

Iterations

Kubernetes.create_and_delete_deployment

10

Kubernetes.create_and_delete_job

10

Kubernetes.create_and_delete_namespace

10

Kubernetes.create_and_delete_pod

10

Kubernetes.create_and_delete_pod_with_configmap_volume

10

Kubernetes.create_and_delete_pod_with_configmap_volume [2]

10

Kubernetes.create_and_delete_pod_with_emptydir_volume

10

Kubernetes.create_and_delete_pod_with_emptydir_volume [2]

10

Kubernetes.create_and_delete_pod_with_hostpath_volume

10

Kubernetes.create_and_delete_pod_with_secret_volume

10

Kubernetes.create_and_delete_pod_with_secret_volume [2]

10

Kubernetes.create_and_delete_replicaset

10

Kubernetes.create_and_delete_replication_controller

10

Kubernetes.create_and_delete_statefulset

10

Kubernetes.create_check_and_delete_pod_with_cluster_ip_service

10

Kubernetes.create_check_and_delete_pod_with_cluster_ip_service [2]

10

Kubernetes.create_check_and_delete_pod_with_node_port_service

10

Kubernetes.create_rollout_and_delete_deployment

10

Kubernetes.create_scale_and_delete_replicaset

10

Kubernetes.create_scale_and_delete_replication_controller

10

Kubernetes.create_scale_and_delete_statefulset

10

Kubernetes.list_namespaces

10

The following software versions are considered to benchmark Kubernetes v1.23 (latest stable release) selected by Anuket:

Table 2.2 Software versions

Software

Version

Functest

v1.23

xrally-kubernetes

1.1.1.dev12

2.2.3. Dataplane benchmarking

Kubernetes perf-tests repository hosts various Kubernetes-related performance test related tools especially netperf which benchmarks Kubernetes networking performance.

As listed in netperf’s README, the 5 major network traffic paths are combination of pod IP vs virtual IP and whether the pods are co-located on the same node versus a remotely located pod:

  • same node using pod IP

  • same node using cluster/virtual IP

  • remote node using pod IP

  • remote node using cluster/virtual IP

  • same node pod hairpin to itself using cluster/virtual IP

It should be noted that netperf leverages iperf (both TCP and UDP modes) and Netperf.

At the time of writing, no KPI is defined in Anuket chapters which would have asked for an update of the default SLA proposed in Functest Kubernetes Benchmarking.

2.2.4. Security testing

There are a couple of opensource tools that help securing the Kubernetes stack. Amongst them, Functest Kubernetes Security offers two test cases based on kube-hunter and kube-bench.

kube-hunter hunts for security weaknesses in Kubernetes clusters and kube-bench checks whether Kubernetes is deployed securely by running the checks documented in the CIS Kubernetes Benchmark.

kube-hunter classifies all vulnerabilities as low, medium, and high. In context of this conformance suite, only the high vulnerabilities lead to a test case failure. Then all low and medium vulnerabilities are only printed for information.

Here are the vulnerability categories tagged as high by kube-hunter:

  • RemoteCodeExec

  • IdentityTheft

  • PrivilegeEscalation

At the time of writing, none of the Center for Internet Security (CIS) rules are defined as mandatory (e.g. sec.std.001: The Cloud Operator should comply with Center for Internet Security CIS Controls) else it would have required an update of the default kube-bench behavior (all failures and warnings are only printed) as integrated in Functest Kubernetes Security.

The following software versions are considered to verify Kubernetes v1.23 (latest stable release) selected by Anuket:

Table 2.3 Software versions

Software

Version

Functest

v1.23

kube-hunter

0.3.1

kube-bench

0.3.1

2.2.5. Opensource CNF onboarding and testing

Running opensource containerized network functions (CNF) is a key technical solution to ensure that the platforms meet Network Functions Virtualization requirements.

Functest CNF offers 2 test cases which automatically onboard and test Clearwater IMS via kubectl and Helm. It’s worth mentioning that this CNF is covered by the upstream tests (see clearwater-live-test).

The following software versions are considered to verify Kubernetes v1.23 (latest stable release) selected by Anuket:

Table 2.4 Software versions

Software

Version

Functest

v1.23

clearwater

release-130

Helm

v3.3.1

2.3. Test Cases Traceability to Requirements

The following test case must pass as they are for Reference Conformance:

Table 2.5 Mandory test cases

Container

Test suite

Criteria

Requirements

opnfv/functest-kubernetes-smoke:v1.23

xrally_kubernetes

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

k8s_conformance

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

k8s_conformance_serial

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_api_machinery

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_api_machinery_serial

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_apps

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_apps_serial

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_auth

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_cluster_lifecycle

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_instrumentation

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_network

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_node

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_scheduling_serial

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_storage

PASS

Kubernetes API testing

opnfv/functest-kubernetes-smoke:v1.23

sig_storage_serial

PASS

Kubernetes API testing

opnfv/functest-kubernetes-security:v1.23

kube_hunter

PASS

Security testing

opnfv/functest-kubernetes-security:v1.23

kube_bench_master

PASS

Security testing

opnfv/functest-kubernetes-security:v1.23

kube_bench_node

PASS

Security testing

opnfv/functest-kubernetes-benchmarking:v1.23

xrally_kubernetes_full

PASS

Kubernetes API benchmarking

opnfv/functest-kubernetes-benchmarking:v1.23

netperf

PASS

Dataplane benchmarking

opnfv/functest-kubernetes-cnf:v1.23

k8s_vims

PASS

Opensource CNF onboarding and testing

opnfv/functest-kubernetes-cnf:v1.23

helm_vims

PASS

Opensource CNF onboarding and testing