Automated testing

Unit testing and code quality

Use the make test command.

QEMU and Kubernetes

E2E testing relies on a cluster running inside multiple QEMU virtual machines deployed by GoVM. The same cluster can also be used interactively when real hardware is not available.

E2E testing is known to work on a Linux development host system. The user must be allowed to use Docker.

KVM must be enabled. Usually this is the case when /dev/kvm exists. The current user does not need the privileges to use KVM and QEMU doesn’t have to be installed because GoVM will run QEMU inside a container with root privileges.

Note that cloud providers often don’t offer KVM support on their regular machines. Search for “nested virtualization” for your provider to determine whether and how it supports KVM.

Nested virtualization is also needed when using Kata Containers inside the cluster. On Intel-based machines it can be enabled by loading the kvm_intel module with nested=1 (see At this time, Kata Containers up to and including 1.9.1 is not compatible with PMEM-CSI because volumes are not passed in as PMEM, but Kata Containers can be installed and used for applications that are not using PMEM.

PMEM-CSI images must have been created and published in some Docker registry, as described earlier in build PMEM-CSI. In addition, that registry must be accessible from inside the cluster. That works for the default (a local registry in the build host) but may require setting additional configuration options for other scenarios.

Starting and stopping a test cluster

make start will bring up a Kubernetes test cluster inside four QEMU virtual machines. The first node is the Kubernetes master without persistent memory. The other three nodes are worker nodes with one emulated 32GB NVDIMM each. After the cluster has been formed, make start installs NFD to label the worker nodes. The PMEM-CSI driver can be installed with test/, but will also be installed as needed by the E2E test suite.

Once make start completes, the cluster is ready for interactive use via kubectl inside the virtual machine. Alternatively, you can also set KUBECONFIG as shown at the end of the make start output and use kubectl binary on the host running VMs.

Use make stop to stop and remove the virtual machines.

make restart can be used to cleanly reboot all virtual machines. This is useful during development after a make push-images to ensure that the cluster runs those rebuilt images. However, for that to work the image pull policy has to be changed from the default “if not present” to “always” by setting the TEST_IMAGE_PULL_POLICY environment variable to Always.

Running commands on test cluster nodes over ssh

make start generates ssh wrapper scripts _work/pmem-govm/ssh.N for each test cluster node which are handy for running a single command or to start an interactive shell. Examples:

_work/pmem-govm/ssh.0 kubectl get pods runs a kubectl command on the master node.

_work/pmem-govm/ssh.1 starts a shell on the first worker node.

Deploying PMEM-CSI on a test cluster

After make start, PMEM-CSI is not installed yet. Either install manually as described for a normal cluster or use the script.

Configuration options

Several aspects of the cluster and build setup can be configured by overriding the settings in the file. See that file for a description of all options. Options can be set as environment variables of make start on a case-by-case basis or permanently by creating a file like test/test-config.d/

Multiple different clusters can be brought up in parallel by changing the default pmem-govm cluster name via the CLUSTER env variable.

For example, this invocation sets up a cluster using an older release of Kubernetes:

TEST_KUBERNETES_VERSION=1.18 CLUSTER=kubernetes-1.18 make start

See additional details in test/test-config.d.

Running E2E tests

make test_e2e will run csi-test sanity tests and some Kubernetes storage tests against the PMEM-CSI driver.

When ginkgo is installed, then it can be used to run individual tests and to control additional aspects of the test run. For example, to run just the E2E provisioning test (create PVC, write data in one pod, read it in another) in verbose mode:

$ KUBECONFIG=$(pwd)/_work/pmem-govm/kube.config REPO_ROOT=$(pwd) ginkgo -v -focus=pmem-csi.* ./test/e2e/
Nov 26 11:21:28.805: INFO: The --provider flag is not set.  Treating as a conformance test.  Some tests may not be run.
Running Suite: PMEM E2E suite
Random Seed: 1543227683 - Will randomize all specs
Will run 1 of 61 specs

Nov 26 11:21:28.812: INFO: checking config
Nov 26 11:21:28.812: INFO: >>> kubeConfig: /nvme/gopath/src/
Nov 26 11:21:28.817: INFO: Waiting up to 30m0s for all (but 0) nodes to be schedulable
Ran 1 of 61 Specs in 58.465 seconds
SUCCESS! -- 1 Passed | 0 Failed | 0 Pending | 60 Skipped

Ginkgo ran 1 suite in 1m3.850672246s
Test Suite Passed

It is also possible to run just the sanity tests until one of them fails:

$ REPO_ROOT=`pwd` ginkgo '-focus=sanity' -failFast ./test/e2e/

Testing on an existing cluster

This can be done by emulating what make start does when setting up a QEMU-based cluster. Here is a (not necessarily complete) list:

  • Prepare a directory outside of _work with the following files.

  • Create ssh.<0 to number of nodes -1> scripts such that each script logs into the corresponding node or executes commands. For example:

$ cat igk/ssh.0

ssh igk-1 "$@"
  • Create ssh.<host name> symlinks to the corresponding ssh.<number> file.

  • Create a kubernetes.version file with <major>.<minor> versions, for example 1.19.

  • Create kube.config and ensure that a local kubectl command can use it to connect to the cluster. SSH portforwarding may be necessary for remote clusters. The config must grant admin permissions.

  • Ensure that ssh.<number> <command> works for the following commands:

    • kubectl get nodes (only needed for ssh.0)

    • sudo pvs

    • sudo ndctl list -NR

  • Label all worker nodes with PMEM with storage=pmem and

  • Delete all namespaces.

  • On OpenShift 4.6 and 4.7: create the scheduler-policy config map with a fixed host port (default: TEST_SCHEDULER_EXTENDER_NODE_PORT=32000) and reconfigure scheduler/cluster as explained in OpenShift scheduler configuration. There is one crucial difference for the config map: in the managedResources array, it must also include an entry for (use by operator-lvm-production). The corresponding service will be created when deploying PMEM-CSI as part of the tests.

  • Symlink _work/<cluster> to the directory.

  • Push a pmem-csi-driver image to a registry that the cluster can pull from. The normal make push-images and make test_e2e work when overriding the test config with a test/test-config.d/ file that has the following content. This is just an example, also works.
  • Run CLUSTER=<cluster> TEST_HAVE_OLM=false make test_e2e TEST_E2E_SKIP="raw.conversion". On OpenShift, use TEST_HAVE_OLM=true. The only direct TCP connection is the one for the API server, so with port forwarding a single developer machine can test multiple different remote clusters.

Using ndctl on an OS which does not provide it

If ndctl is not available for the OS but containers can be run, then the following workaround is possible. Create a wrapper script:

sudo tee /usr/local/bin/ndctl <<EOF

podman run --privileged -u 0:0 --rm ndctl "\$@"
sudo chmod a+rx /usr/local/bin/ndctl

Then ensure that sudo ndctl finds the wrapper there:

sudo sed -i -e 's;\(secure_path.*\);\1:/usr/local/bin;' /etc/sudoers