Integration Tests of Cockpit

This directory contains automated integration tests for Cockpit, and the support files for them. The architecture of the automated integration tests is described in ARCHITECTURE

To run the tests on Fedora, refer to the HACKING guide for installation of all of the necessary build and test dependencies. There’s no need to trigger a build manually - the test suite preparation step below will handle that.

If test failures are encountered that look like they may be related to problems with nested virtualization, refer to this Fedora guide for more details and recommendations on ensuring it is enabled correctly.

Preparation and general invocation

Warning: Never run the build, test, or any other command here as root!

You first need to build cockpit, and install it into a VM:


This uses the default OS image, which is currently Fedora 39. See $TEST_OS below how to select a different one.

In most cases you want to run an individual test in a suite, for example:

test/verify/check-metrics TestCurrentMetrics.testCPU

You can get a list of tests by inspecting the def test* in the source, or by running the suite with -l/--list:

test/verify/check-metrics -l

Sometimes you may also want to run all tests in a test file suite:


To see more verbose output from the test, use the -v/--verbose and/or -t/--trace flags:

test/verify/check-session --verbose --trace

If you specify -s/--sit in addition, then the test will wait on failure and allow you to log into cockpit and/or the test instance and diagnose the issue. The cockpit and SSH addresses of the test instance will be printed:

test/verify/check-session -st

You can also run all the tests, with some parallelism:

test/common/run-tests --test-dir test/verify --jobs 2

However, this will take really long. You can specify a subset of tests (see --help); but usually it’s better to run individual tests locally, and let the CI machinery run all of them in a draft pull request.

The tests will automatically download the VM images they need, so expect that the initial run may take a few minutes.

Interactive browser

Normally each test starts its own chromium headless browser process on a separate random port. To interactively follow what a test is doing:

TEST_SHOW_BROWSER=1 test/verify/check-session --trace

You can also run a test against Firefox instead of Chromium:

TEST_BROWSER=firefox test/verify/check-session --trace

See below for details.

Manual testing

You can conduct manual interactive testing against a test image by starting the image like so:

 bots/vm-run -s cockpit.socket debian-stable

Once the machine is booted and the cockpit socket has been activated, a message will be printed describing how to access the virtual machine, via ssh and web. See the “Helpful tips” section below.

By default, it’s only possible to contact the virtual machine from the host machine on which it’s running. If you want to conduct manual testing from other devices on your network, set TEST_BIND_GLOBAL=1, for example:

 TEST_BIND_GLOBAL=1 bots/vm-run -s cockpit.socket debian-stable

This will bind the Cockpit and SSH ports to all interfaces, making it possible to access a URL like http://yourhost.local:9091/ to test Cockpit from another machine on your LAN.

Pixel tests

Pixel tests in Cockpit ensure that updates of our dependencies or code changes don’t break the UI: for example slight changes of layout, padding, color and everything which isn’t easily spotted by a human. They also give us confidence that an update of our UI Framework doesn’t introduce changes in how Cockpit looks.

Pixel tests make a screenshot of a selector and compare it to a known good reference image. if there is a difference, the test fails and a pixel difference is shown.

This works as our tests run in the cockpit/tasks container which pins the browser and font rendering so repeated runs provide the same pixels. To generate new pixels, this tasks container must be used; your own browser and font rendering software might generate different results. For more information read the “introduction blog post”.

The test images are stored in a git submodule in the test/reference directory and be fetched with:

./test/common/pixel-tests update

As Cockpit tests under multiple distributions and it is not worth the effort to run pixel tests on every supported distribution we only run them for the image configured in test/reference-image.

Our tests call Browser.assert_pixels at interesting and strategic places. This assertion method requires at least a CSS selector and an image title. Pixel tests are generated in five layouts by default: desktop, medium, mobile, dark and rtl.

Take a screenshot of the content in #detail-content:

browser.assert_pixels("#detail-content", "filesystem")

Take a screenshot of the content in #detail-content and ignore all elements with a class disk-stats as they change per test run:

browser.assert_pixels("#detail-content", "filesystem", ignore=[".disks-stats"])

Take a screenshot of the content in #detail-content and skip it for a specific layout as it generates unstable pixels:

browser.assert_pixels("#detail-content", "filesystem", skip_layouts=["rtl"])

To update pixel tests, locally run the test in the current tasks container, or create a draft PR and let the tests run for test/reference-image and afterwards fetch the new pixels:

./test/common/pixel-tests fetch "<snip>/log.html"

Finally, upload the new pixel tests and commit the newly generated submodule commit:

./test/common/pixel-tests push

Note that you have to a part of the Contributors group to push pixel tests.

Test Configuration

You can set these environment variables to configure the test suite:

TEST_OS    The OS to run the tests in.  Currently supported values:
           "fedora-39" is the default (TEST_OS_DEFAULT in bots/lib/

TEST_JOBS  How many tests to run in parallel.  The default is 1.

TEST_CDP_PORT  Attach to an actually running browser that is compatible with
               the Chrome Debug Protocol, on the given port. Don't use this
               with parallel tests.

TEST_BROWSER  What browser should be used for testing. Currently supported values:
              "chromium" is the default.

TEST_SHOW_BROWSER  Set to run browser interactively. When not specified,
                   browser is run in headless mode. When set to "pixels",
                   the browser will be resized to the exact dimensions that
                   are used for pixel tests.

TEST_TIMEOUT_FACTOR Scale normal timeouts by given integer. Useful for
                    slow/busy testbeds or architectures.

See the bots documentation for details about the tools and configuration for these.

Convenient test VM SSH access

It is recommended to add a snippet like this to your ~/.ssh/config. Then you can log in to test machines without authentication:

Match final host
    User root
    StrictHostKeyChecking no
    UserKnownHostsFile /dev/null
    CheckHostIp no
    IdentityFile CHECKOUT_DIR/bots/machine/identity
    IdentitiesOnly yes

You need to replace CHECKOUT_DIR with the actual directory where you cloned cockpit.git, or bots.git if you have a separate clone for that.

Many cockpit developers take it a step further, and add an alias to allow typing ssh c:

Host c
    Port 2201

The final keyword in the first rule will cause it to be checked (and matched) after the Hostname substitution in the c rule.

Fast develop/test iteration

Each image-prepare invocation will always start from the pristine image and ignore the current overlay in test/images. It is thorough, but also rather slow. If you want to iterate on changing only JavaScript/HTML code, as opposed to the bridge or webserver, the whole build and test cycle can be done much faster.

You always need to do at least one initial test/image-prepare $TEST_OS run. Afterwards it depends on the kind of test you want to run.

Nondestructive tests

Many test methods or classes are marked as @nondestructive, meaning that they restore the state of the test VM enough that other tests can run afterwards. This is the fastest and most convenient situation for both iterating on the code and debugging failing tests.

Start the prepared VM with bots/vm-run $TEST_OS. Note the SSH and cockpit ports. If this is the only running VM, it will have the ports in the examples below, otherwise the port will be different.

Then start building the page you are working on in watch and rsync mode, e.g.

RSYNC=c ./build.js -w users

(Assuming the c SSH alias from the previous section and first running VM).

Then you can run a corresponding test against the running VM, with additional debug output:

TEST_OS=... test/verify/check-users -t --machine --browser TestAccounts.testBasic

Destructive tests

Other tests need one or more fresh VMs. Instead of a full test/image-prepare run (which is slow), you can update the existing VM overlay with updated bundles. Start the build in watch mode, but without rsyncing, e.g.

./build.js -w storaged

and after each iteration, copy the new bundles into the VM overlay:

bots/image-customize -u dist:/usr/share/cockpit/ $TEST_OS

Then run the test as you would normally do, e.g.

TEST_OS=... test/verify/check-storage-stratis -t TestStorageStratis.testBasic

Use bots/vm-reset to clean up all prepared overlays in test/images.

Debugging tests

If you pass the -s (“sit on failure”) option to a test program, it will pause when a failure occurs so that you can log into the test machine and investigate the problem.

A test will print out the commands to access it when it fails in this way. You can log into a running test-machine using ssh. See the “Helpful tips” section below.

You can also put calls to sit() into the tests themselves to stop them at strategic places.

That way, you can run a test cleanly while still being able to make quick changes, such as adding debugging output to JavaScript.

Guidelines for writing tests

If a test is not decorated with @nondestructive, it is OK for a test to destroy the test machine OS installation, or otherwise modify it without cleaning up. For example, it is OK to remove all of /etc just to see what happens. The next test will get a pristine test machine.

Tests decorated with @nondestructive will all run against the same test machine. The nondestructive test should clean up after itself and restore the state of the machine, such that the next nondestructive test is not impacted.

A fast running test suite is more important than independent, small test cases.

Thus, it is OK for tests to be long. Starting the test machine is so slow that we should run as many checks within a single session as make sense. Note that nondestructive tests do not suffer from this, and are much quicker.

Still, within a long test, try to have independent sections, where each section returns the machine to more or less the state that it was in before the section. This makes it easier to run these sections ad-hoc when doing incremental development.


Every pull request will trigger a $DEFAULT_OS/devel scenario which creates a coverage report of the JavaScript code executed and writes comments about uncovered code in the pull request. The overall coverage percentage is recorded in prometheus for a subset of our projects and visualized in Grafana.

To generate coverage locally for TestApps:

export NODE_ENV=devel
./test/image-prepare -q
./test/common/run-tests --test-dir test/verify --coverage TestApps

Code which is impossible or very hard to test in our tests can be excluded from appearing in a pull request as comment by adding a not-covered comment with a short justification:

return cockpit.script(data, { superuser: "try", err: "message" })
              .catch(console.error); // not-covered: OS error

Helpful tips

For web access, if you’d like to avoid Chromium (or Chrome) prompting about certificate errors while connecting to localhost, you can change the following setting: