lets_write_a_test.md

The Task

We will write a test to check if a package (specifically HTTPD) is installed and running. To do this we will write two files:

1. install.rb - This file will install the package and start the service
2. mytest.rb - This file will have our core tests that checks if the package is installed and running

Note: We will exclude Windows OS from our testing due to variation of package name.

Figure out steps

What needs to happen in this test:

• Install and run HTTPD
  • Install HTTPD if its not available on our SUT
  • Start HTTPD service
• Testing
  • Test HTTPD is installed
  • Test HTTPD service is running

Create a host configuration file

    $ beaker-hostgenerator redhat7-64 > redhat7-64.yaml

This command will generate a host file for our system under test (SUT). It will use vmpooler as hypervisor for the host. Please check out this doc to learn more about hypervisors for beaker.

Install and run HTTPD

Make a file named install.rb and put the following code into it:

test_name "Installing and runnning HTTPD" do

  # Don't run the install script on the following platform
  confine :except, :platform => 'windows'

  step "Install HTTPD" do
    hosts.each do |host|
      # Install HTTPD if it is not available on our SUT
      install_package(host, 'httpd') unless check_for_package(host, 'httpd')
    end
  end

  step "Start HTTPD" do
    hosts.each do |host|
      # Start HTTPD service
      on(host, "service httpd start")
    end
  end

end

This places our install steps in a ruby script (install.rb) which will run on your SUT. The install.rb script is used in our commandline to beaker, below.

Create a test file

Lets create test file that tests if HTTPD is installed and running on our hosts. Make a file called mytest.rb and add the following code to it:

test_name "Check if HTTPD is installed and running" do

  # Don't run these tests on the following platform
  confine :except, :platform => 'windows'

  step "Make sure HTTPD is installed" do
    hosts.each do |host|
      # Check if HTTPD is installed
      assert check_for_package(host, 'httpd')
    end
  end

  step "Make sure HTTPD is running" do
    hosts.each do |host|
      on(host, "systemctl is-active httpd") do |result|
        # Check if HTTPD is running
        assert_equal(0, result.exit_code)
      end
    end
  end

end

Run it!

You can now run this with

$ beaker --host redhat7-64ma.yaml --pre-suite install.rb --tests mytest.rb

Creating the host configuration on at runtime

When you don't want to store a static file, you can also let beaker-hostgenerator generate it on the fly. The filename is used as a host specification. A simple example is:

$ beaker --host centos7-64 --pre-suite install.rb --tests mytest.rb

It's also possible to set the hypervisor and hostname:

$ beaker --host 'centos7-64{hypervisor=docker,hostname=centos7-64.example.com}' --pre-suite install.rb --tests mytest.rb

An alternative way to set the hypervisor is BEAKER_HYPERVISOR:

$ BEAKER_HYPERVISOR=docker beaker --host centos7-64 --pre-suite install.rb --tests mytest.rb

Next up you may want to look at the Beaker test for a module page.