[OPENJDK-1549] test for cleaned Maven environment

Perform an S2I 'build' of a test Maven project. Define
MAVEN_ARGS for two purposes:

1. so that it exists in the environment prior to invoking Mvn
2. In order to specify the phase 'validate'

The preferred way to achieve (2) is by defining MAVEN_S2I_GOALS,
but defining MAVEN_ARGS for (1) overrides that value.

Please note the chicken-and-egg problem with defining this test. The
test needs to clone the Maven project from a git repository. Until the
PR introducing the test is merged, it does not exist in the main URI.
Therefore I have referenced my GitHub fork from which the PR is being
raised. If/once accepted, a future patch could change 'jmtd' to
'jboss-container-images' and 'OPENJDK-1549-maven-args-take-2' to 'ubi9'
so that the test tracks any changes made to the project in the main
line.

A future enhancement to behave-test-steps may be to permit S2I builds
from a local path relative to the image source repository rather than
requiring an absolute URI to clone from. That would remove the need for
the above.

Signed-off-by: Jonathan Dowland <[email protected]>

Author: jmtd

tests/features/java/java_s2i.feature

@@ -166,3 +166,8 @@ Feature: Openshift OpenJDK S2I tests
        | ns     | http://maven.apache.org/SETTINGS/1.0.0 |
     Then XML file /tmp/artifacts/configuration/settings.xml should have 1 elements on XPath //ns:server[ns:id='myrepo']
     Then XML file /tmp/artifacts/configuration/settings.xml should have 1 elements on XPath //ns:profile[ns:id='myrepo-profile']/ns:repositories/ns:repository[ns:url='http://repo.example.com:8080/maven2/']
+
+  Scenario: Ensure the environment is cleaned when executing mvn (OPENJDK-1549)
+      Given s2i build https://github.com/jmtd/openjdk from tests/OPENJDK-1549 with env using OPENJDK-1549-maven-args-take-2
+       | variable           | value    |
+       | MAVEN_ARGS         | validate |