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Run tests and test documentation
Contributing includes testing your changes. If you change the Docker code, you may need to add a new test or modify an existing one. Your contribution could even be adding tests to Docker. For this reason, you need to know a little about Docker's test infrastructure.
Many contributors contribute documentation only. Or, a contributor makes a code contribution that changes how Docker behaves and that change needs documentation. For these reasons, you also need to know how to build, view, and test the Docker documentation.
In this section, you run tests in the dry-run-test
branch of your Docker
fork. If you have followed along in this guide, you already have this branch.
If you don't have this branch, you can create it or simply use another of your
branches.
Understand testing at Docker
Docker tests use the Go language's test framework. In this framework, files
whose names end in _test.go
contain test code; you'll find test files like
this throughout the Docker repo. Use these files for inspiration when writing
your own tests. For information on Go's test framework, see Go's testing package
documentation and the go test help.
You are responsible for unit testing your contribution when you add new or change existing Docker code. A unit test is a piece of code that invokes a single, small piece of code ( unit of work ) to verify the unit works as expected.
Depending on your contribution, you may need to add integration tests. These
are tests that combine two or more work units into one component. These work
units each have unit tests and then, together, integration tests that test the
interface between the components. The integration
and integration-cli
directories in the Docker repository contain integration test code.
Testing is its own specialty. If you aren't familiar with testing techniques, there is a lot of information available to you on the Web. For now, you should understand that, the Docker maintainers may ask you to write a new test or change an existing one.
Run tests on your local host
Before submitting any code change, you should run the entire Docker test suite.
The Makefile
contains a target for the entire test suite. The target's name
is simply test
. The make file contains several targets for testing:
Target | What this target does |
---|---|
test | Run all the tests. |
test-unit | Run just the unit tests. |
test-integration-cli | Run the test for the integration command line interface. |
test-docker-py | Run the tests for Docker API client. |
Run the entire test suite on your current repository:
-
Open a terminal on your local host.
-
Change to the root your Docker repository.
$ cd docker-fork
-
Make sure you are in your development branch.
$ git checkout dry-run-test
-
Run the
make test
command.$ make test
This command does several things, it creates a container temporarily for testing. Inside that container, the
make
:- creates a new binary
- cross-compiles all the binaries for the various operating systems
- runs all the tests in the system
It can take several minutes to run all the tests. When they complete successfully, you see the output concludes with something like this:
[PASSED]: top - sleep process should be listed in privileged mode [PASSED]: version - verify that it works and that the output is properly formatted PASS coverage: 70.8% of statements ---> Making bundle: test-docker-py (in bundles/1.5.0-dev/test-docker-py) +++ exec docker daemon --debug --host unix:///go/src/github.com/docker/docker/bundles/1.5.0-dev/test-docker-py/docker.sock --storage-driver vfs --exec-driver native --pidfile /go/src/github.com/docker/docker/bundles/1.5.0-dev/test-docker-py/docker.pid ................................................................. ---------------------------------------------------------------------- Ran 65 tests in 89.266s
Run test targets inside the development container
If you are working inside a Docker development container, you use the
hack/make.sh
script to run tests. The hack/make.sh
script doesn't
have a single target that runs all the tests. Instead, you provide a single
command line with multiple targets that does the same thing.
Try this now.
-
Open a terminal and change to the
docker-fork
root. -
Start a Docker development image.
If you are following along with this guide, you should have a
dry-run-test
image.$ docker run --privileged --rm -ti -v `pwd`:/go/src/github.com/docker/docker dry-run-test /bin/bash
-
Run the tests using the
hack/make.sh
script.root@5f8630b873fe:/go/src/github.com/docker/docker# hack/make.sh dynbinary binary cross test-unit test-integration-cli test-docker-py
The tests run just as they did within your local host.
Of course, you can also run a subset of these targets too. For example, to run just the unit tests:
root@5f8630b873fe:/go/src/github.com/docker/docker# hack/make.sh dynbinary binary cross test-unit
Most test targets require that you build these precursor targets first:
dynbinary binary cross
Running individual or multiple named tests
We use gocheck for our integration-cli tests.
You can use the TESTFLAGS
environment variable to run a single test. The
flag's value is passed as arguments to the go test
command. For example, from
your local host you can run the TestBuild
test with this command:
$ TESTFLAGS='-check.f DockerSuite.TestBuild*' make test-integration-cli
To run the same test inside your Docker development container, you do this:
root@5f8630b873fe:/go/src/github.com/docker/docker# TESTFLAGS='-check.f TestBuild*' hack/make.sh binary test-integration-cli
Testing the Windows binary against a Linux daemon
This explains how to test the Windows binary on a Windows machine set up as a development environment. The tests will be run against a docker daemon running on a remote Linux machine. You'll use Git Bash that came with the Git for Windows installation. Git Bash, just as it sounds, allows you to run a Bash terminal on Windows.
-
If you don't have one open already, start a Git Bash terminal.
-
Change to the
docker
source directory.$ cd /c/gopath/src/github.com/docker/docker
-
Set
DOCKER_REMOTE_DAEMON
as follows:$ export DOCKER_REMOTE_DAEMON=1
-
Set
DOCKER_TEST_HOST
to thetcp://IP_ADDRESS:2376
value; substitute your Linux machines actual IP address. For example:$ export DOCKER_TEST_HOST=tcp://213.124.23.200:2376
-
Make the binary and run the tests:
$ hack/make.sh binary test-integration-cli
Some tests are skipped on Windows for various reasons. You can see which tests were skipped by re-running the make and passing in the
TESTFLAGS='-test.v'
value. For example$ TESTFLAGS='-test.v' hack/make.sh binary test-integration-cli
Should you wish to run a single test such as one with the name 'TestExample', you can pass in
TESTFLAGS='-check.f TestExample'
. For example$TESTFLAGS='-check.f TestExample' hack/make.sh binary test-integration-cli
You can now choose to make changes to the Docker source or the tests. If you make any changes just run these commands again.
Build and test the documentation
The Docker documentation source files are under docs
. The content is
written using extended Markdown. We use the static generator MkDocs to build Docker's
documentation. Of course, you don't need to install this generator
to build the documentation, it is included with container.
You should always check your documentation for grammar and spelling. The best way to do this is with an online grammar checker.
When you change a documentation source file, you should test your change locally to make sure your content is there and any links work correctly. You can build the documentation from the local host. The build starts a container and loads the documentation into a server. As long as this container runs, you can browse the docs.
-
In a terminal, change to the root of your
docker-fork
repository.$ cd ~/repos/docker-fork
-
Make sure you are in your feature branch.
$ git status On branch dry-run-test Your branch is up-to-date with 'origin/dry-run-test'. nothing to commit, working directory clean
-
Build the documentation.
$ make docs
When the build completes, you'll see a final output message similar to the following:
Successfully built ee7fe7553123 docker run --rm -it -e AWS_S3_BUCKET -e NOCACHE -p 8000:8000 "docker-docs:dry-run-test" mkdocs serve Running at: http://0.0.0.0:8000/ Live reload enabled. Hold ctrl+c to quit.
-
Enter the URL in your browser.
If you are using Docker Machine, replace the default localhost address (0.0.0.0) with your DOCKERHOST value. You can get this value at any time by entering
docker-machine ip <machine-name>
at the command line. -
Once in the documentation, look for the red notice to verify you are seeing the correct build.
-
Navigate to your new or changed document.
-
Review both the content and the links.
-
Return to your terminal and exit out of the running documentation container.
Where to go next
Congratulations, you have successfully completed the basics you need to understand the Docker test framework. In the next steps, you use what you have learned so far to contribute to Docker by working on an issue.