What Free Tools For Testing CLI on Linux, Windows, Mac?

We have a Java application that has a customer facing CLI and web browser GUI. The app runs on Linux, Windows, and Mac. We are researching what tools we should use to test the app both CLI and web.

To date we have a very basic test framework based on Docker to the test the CLI. We implemented some TestNG Java code which runs the app in docker containers and checks the output.

We have looked at Docker for Windows but Docker containers are limited to Windows Server 2016 and we need to support older Windows Server and desktop platforms.

We probably will go with Sellenium or similar for the web testing.

We do have a VMware Workstation based VM environment we can run all the Windows tests in.

Here's what we think we need based on what we implemented with Docker already: - Launch a given VMware vm at start of test - Copy app to vm and run installer - Run test harness to run app and test CLI - Report back failures/success - Shutdown and revert snapshot of vm when test finished

Any suggestions on what testing tools can do the above? Free tools are preferred but we are open to commercial tools. One tool for CLI and web would be great but we already assume we will have to have 2 different tools.