Use TestCafe Docker Image

TestCafe provides a preconfigured Docker image with Chromium and Firefox installed. Therefore, you can avoid manual installation of browsers and the testing framework on the server.

Install Docker and Download TestCafe Image

To learn how to install Docker on your system, see Install Docker.

After Docker is installed, download the TestCafe Docker image from the repository.

docker pull testcafe/testcafe

The command above installs a stable version of the image. If you need an alpha version, run the following command.

docker pull testcafe/testcafe:alpha

Test in Docker Containers

Use the docker run command to run TestCafe in the Docker container:

docker run -v ${TEST_FOLDER}:/tests -it testcafe/testcafe ${TESTCAFE_ARGS}

This command takes the following parameters:

  • -v ${TEST_FOLDER}:/tests - maps the TEST_FOLDER directory on the host machine to the /tests directory in the container. You can map any host directory to any container directory:

    -v //c/Users/Username/tests:/tests

    -v //d/tests:/myTests

    Files referenced in tests (page models, utilities, Node.js modules) should be located in the mapped host directory or its subdirectories. Otherwise, they could not be accessed from the container.

    Share a drive to reach it from Docker containers. For more information, see the Docker for Windows documentation.

  • -it testcafe/testcafe - runs TestCafe in the interactive mode with the console enabled;

  • ${TESTCAFE_ARGS} - arguments passed to the testcafe command. You can use any arguments from the TestCafe command line interface;

    -it testcafe/testcafe chromium,firefox /tests/test.js

    You can pass a glob instead of the directory path in TestCafe parameters.

    docker run -v //d/tests:/tests -it testcafe/testcafe firefox /tests/**/*.js

    If tests use other Node.js modules, these modules should be located in the tests directory or its child directories. TestCafe will not be able to find modules in the parent directories.

Test on the Host Machine

To run tests in host machine browsers, connect them as remote browsers. Do the following:

  • pass the --net=host parameter to specify that the container should use the host network;
  • specify the remote keyword as the browser name.
docker run --net=host -v /d/tests:/tests -it testcafe/testcafe remote /tests/test.js

Note that the --net=host option can weaken container security. If this is important for you, you can follow the instruction in the Test on Remote Devices section instead. In this case, specify localhost as the hostname and omit the --add-host parameter.

Test on Remote Devices

Add the following options to the docker run command to run tests on a remote desktop or mobile device:

  • map the 1337 and 1338 container ports to the corresponding host ports with the -p flag;
  • use the --hostname TestCafe flag to specify the host machine name;
  • pass the --add-host parameter to map the host machine name to the container's localhost IP;
  • specify the remote keyword as the browser name. See Remote Browsers.

The example below shows a command that runs tests in a remote browser.

docker run --add-host=${EXTERNAL_HOSTNAME}:127.0.0.1 -p 1337:1337 -p 1338:1338 -v /d/tests:/tests -it testcafe/testcafe --hostname ${EXTERNAL_HOSTNAME} remote /tests/test.js

where ${EXTERNAL_HOSTNAME} is the host machine name visible to the remote device.

If Docker reports that the default ports 1337 and 1338 are occupied by some other process, kill this process or choose different ports. Use the netstat command to determine which process occupies the default ports.

OS Command
Windows netstat -ano
macOS netstat -anv
Linux netstat -anp

If you choose to use different ports, publish them in the Docker container (use the -p flag) and specify them to TestCafe (use the --ports option).

docker run --add-host=${EXTERNAL_HOSTNAME}:127.0.0.1 -p ${PORT1}:${PORT1} -p ${PORT2}:${PORT2} -v /d/tests:/tests -it testcafe/testcafe --hostname ${EXTERNAL_HOSTNAME} --ports ${PORT1},${PORT2} remote /tests/test.js

where ${PORT1} and ${PORT2} are vacant container's ports, ${EXTERNAL_HOSTNAME} is the host machine name.

Proxy Settings

Use the TestCafe --proxy and --proxy-bypass options to configure proxy settings.

docker run -v /d/tests:/tests -it testcafe/testcafe remote /tests/test.js --proxy proxy.mycorp.com

TestCafe ignores the container's proxy settings specified in the Docker configuration file (httpProxy, httpsProxy and noProxy) or the environment variables (HTTP_PROXY, HTTPS_PROXY and NO_PROXY).

Troubleshooting

'Unable to establish one or more of the specified browser connections' error when running Chrome/Chromium in a CI system

Chromium cannot run in an unprivileged container without the --no-sandbox flag. TestCafe automatically detects if Chromium runs in Docker and adds --no-sandbox. Additionally, TestCafe specifies the --disable-dev-shm-usage flag to prevent the /dev/shm storage overflow.

However, some CI systems' configurations interfere with this detection logic, so that it fails to identify Docker and does not add the flags. In this instance, TestCafe throws the Unable to establish one or more of the specified browser connections error. If you see this error, try to add the flags in the docker run command:

docker run -v /d/tests:/tests -it testcafe/testcafe 'chrome --no-sandbox --disable-dev-shm-usage' /tests/test.js