Validation

End-to-end (e2e) tests for Kubernetes provide a mechanism to test the behaviour of the system. This is a useful indicator that the cluster is performing properly, as well as a good validation of any code changes.

For Charmed Kubernetes, these tests are encapsulated in an additional Juju charm which can be added to your cluster. Actual testing is then run through the charm’s actions.

<span class="p-notification__title">Caution:</span>
<p class="p-notification__message">Your cluster will need to have at least two running worker units for the `e2e` test to run properly.</div>

Deploying the kubernetes-e2e charm

Add the charm to your cluster:

juju deploy kubernetes-e2e --constraints mem=4G

We also need to configure the charm to select the appropriate version of tests. This relates to the installed version of Kubernetes. You can check which version your cluster is set to by running:

juju config kubernetes-control-plane channel

The output will be in the form of version.number/risk, e.g 1.24/stable. You should set the kubernetes-e2e channel to the same value.

juju config kubernetes-e2e channel=1.24/stable

Finally we relate the charm to easyrsa and kubernetes-control-plane:

juju config kubernetes-control-plane allow-privileged=true
juju add-relation kubernetes-e2e easyrsa
juju add-relation kubernetes-e2e:kubernetes-control-plane kubernetes-control-plane:kube-api-endpoint
juju add-relation kubernetes-e2e:kube-control kubernetes-control-plane:kube-control

It may take some moments for these relations to establish. Once the connections are made, the charm will update its status to “Ready to test.”

Running the default tests

The tests are configured as a Juju action. To run the default tests:

juju run-action kubernetes-e2e/0 test

The command will return with a uuid for that specific test run. See the section on Test output below for details.

Running specific tests

The complete set of Kubernetes e2e tests is more fully described in the upstream Kubernetes documentation. In some cases you may wish to omit particular groups of tests. This is possible by applying a regular expression defining the tests to omit when initiating the action.

By default, the standard tests marked [Flaky] or [Serial] are skipped. To also omit the tests marked as [Slow], you could run:

juju run-action kubernetes-e2e/0 test skip='\[(Flaky|Slow|Serial)\]'

Note that the brackets for the regex need to be escaped as shown.

Running this command will return a uuid for that specific test run, as with the default case.

Test output

You can check on the current status of the test by running:

juju show-action-status 8f8ec748-6ca7-4bbb-86f8-f37e44ba46f9

where 8f8ec748-6ca7-4bbb-86f8-f37e44ba46f9 is the uuid of the action returned when we initiated the test. This will return YAML output indicating the current status, which can be either running, completed or failed.

actions:
- action: test
  completed at: n/a
  id: 8f8ec748-6ca7-4bbb-86f8-f37e44ba46f9
  status: running
  unit: e2e/0

Once completed, you can see more detail on the timing by running:

juju show-action-status  8f8ec748-6ca7-4bbb-86f8-f37e44ba46f9

Which will return output similar to:

results:
  junit: /home/ubuntu/8f8ec748-6ca7-4bbb-86f8-f37e44ba46f9-junit.tar.gz
  log: /home/ubuntu/8f8ec748-6ca7-4bbb-86f8-f37e44ba46f9.log.tar.gz
status: completed
timing:
  completed: 2018-10-06 18:33:15 +0000 UTC
  enqueued: 2018-10-06 18:25:30 +0000 UTC
  started: 2018-10-06 18:25:30 +0000 UTC

If the tests fail, or you want to look through the detail of each test, you can examine the detailed log.

Viewing test logs

The test logfile is stored as a file on the test instance. The filename corresponds to the uuid of the action which created it, with a ‘.log’ extension, and it is stored in the /home/ubuntu/ directory of the machine where the tests are running. A compressed version is also stored with the extension .log.tar.gz

This log can be copied to your local machine for easier viewing:

juju scp kubernetes-e2e/0:4ceed33a-d96d-465a-8f31-20d63442e51b.log  .

Note that the captured test logfile uses ANSI output, and is best viewed with cat, tail or a similar command which can handle this type of output. Alternatively, you can strip the ANSI parts of the output:

fn=<your log file name>
echo -ne $(cat $fn | sed  's/$/\\n/' | sed 's/\x1B\[[0-9]*\w//g')

<span class="p-notification__title">Caution:</span>
<p class="p-notification__message">If you are running regular tests in this way, it is advisable to remove the generated logs from the test unit. The uncompressed logs in particular can be very large and quickly fill up storage.</p>

Upgrading the e2e tests

When an update is available, the kubernetes-e2e charm can be upgraded with the command:

juju upgrade-charm kubernetes-e2e