Migrating to the Amazon Linux 2 Test Host in AWS Device Farm - AWS Device Farm
Differences between the new and legacy test hosts

Migrating to the Amazon Linux 2 Test Host in AWS Device Farm

Warning

The legacy Android Test Host will no longer be available on October 21, 2024. Note that the process for deprecation is split across several dates:

  • On April 22, 2024, jobs from any new account will be directed to the upgraded test host.

  • On September 2, 2024, all new or modified test spec files must target the upgraded test host.

  • On October 21, 2024, jobs will no longer be able to run on the legacy test host.

Set your test spec files to the amazon_linux_2 host to prevent compatibility issues.

To migrate existing tests from the legacy host to the new Amazon Linux 2 host, develop new test spec files based on your pre-existing ones. The recommended approach is to start with the new default test spec files for your test types. Then, migrate relevant commands from your old test spec file to the new one, saving the old file as a backup. This lets you leverage the optimized default spec for the new host while reusing your existing code. It ensures you get the full benefits of the new host configured optimally for your tests, while retaining your legacy test spec for reference as you adapt commands to the new environment.

The following steps can be used to create a new Amazon Linux 2 test spec file while reusing commands from your old test spec file:

  1. Sign in to the Device Farm console at https://console.aws.amazon.com/devicefarm.

  2. Navigate to the Device Farm project containing your automation tests.

  3. Choose Create a new test run in the project.

  4. Choose a previously used app and test package for your test framework.

  5. Choose Run your test in a custom environment.

  6. Choose the test spec file you are currently using for tests on the legacy test host from the test spec drop-down menu.

  7. Copy the contents of this file and paste them locally in a text editor for reference later on.

  8. In the test spec drop-down menu, change your test spec selection to the most recent default test spec file.

  9. Choose Edit, and you will enter the test spec editing interface. You will notice that, in the first few lines of the test spec file, it has already opted in to the new test host:

    android_test_host: amazon_linux_2

  10. Review the syntax for selecting test hosts here and the key differences between the test hosts here.

  11. Selectively add and edit commands from your locally-saved test spec file from step 6 into the new default test spec file. Then, choose Save as to save the new spec file. You can now schedule test runs on the Amazon Linux 2 test host.

Differences between the new and legacy test hosts

When you're editing your test spec file to use the Amazon Linux 2 test host and transitioning your tests from the legacy test host, be aware of these key environment differences:

  • Selecting software versions: In many instances, the default software versions have changed, so if you weren’t explicitly selecting your software version in the Legacy test host before, you may want to specify it now in the Amazon Linux 2 test host using devicefarm-cli. In the vast majority of use cases, we recommend that customers explicitly select the versions of software they use. By selecting a software version with devicefarm-cli, you’ll have a predictable and consistent experience with it and receive ample amounts of warnings if Device Farm plans to remove that version from the test host.

    Moreover, software selection tools like nvm, pyenv, avm, and rvm have been removed in favor of the new devicefarm-cli software selection system.

  • Available software versions: Many versions of previously pre-installed software have been removed, and many new versions have been added. So, ensure that when using the devicefarm-cli to select your software versions, you select versions which are in the supported version list.

  • Any file paths that are hard-coded in your Legacy host test spec file as absolute paths will most likely not work as expected in the Amazon Linux 2 test host; they're generally not recommended for test spec file use. We recommend that you use relative paths and environment variables for all test spec file code. Moreover, note that most binaries you need for your test can be found in the PATH of the host so that they are immediately runnable from the spec file using just their name (such as appium).

  • Performance data collection isn’t supported on the new test host at this time.

  • Operating System version: The legacy test host was based on the Ubuntu operating system, whereas the new one is based on Amazon Linux 2. As a result, users may notice some differences in the available system libraries and system library versions.

  • For Appium Java users, the new test host does not contain any pre-installed JAR files in its class path, whereas the previous host contained one for the TestNG framework (via an environment variable $DEVICEFARM_TESTNG_JAR). We recommend that customers package the necessary JAR files for their test frameworks inside their test package and remove instances of the $DEVICEFARM_TESTNG_JAR variable from their test spec files. For more information, see Working with Appium and AWS Device Farm.

  • For Appium users, the $DEVICEFARM_CHROMEDRIVER_EXECUTABLE environment variable has been removed in favor of a new approach to enabling customers to access Chromedriver for Android. See our Default test spec file for an example, which uses a new environment variable $DEVICEFARM_CHROMEDRIVER_EXECUTABLE_DIR.

Note

We strongly recommend keeping the existing Appium server command from the default test spec file as is.

We recommend reaching out to the service team through a support case if you have any feedback or questions about the differences between the test hosts from a software perspective.