[OPENJDK-3038] echo out Tech Preview warning

The jlink feature will initially ship as TP.

Repurpose older unit test to check for the TP warning (older test
is redundant as it only worked if jmods are installed). The test
depends upon this being merged first:
cekit/behave-test-steps#73

https://issues.redhat.com/browse/OPENJDK-3038

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

Author: jmtd

modules/jlink/artifacts/opt/jboss/container/java/jlink/preflight.sh

@@ -1,3 +1,14 @@
+jlink_techpreview_warning()
+{
+  {
+    echo "WARNING WARNING WARNING"
+    echo "        Jlink integration is a Tech Preview feature!"
+    echo "        See <https://access.redhat.com/support/offerings/techpreview/>"
+    echo "        for more information."
+    echo "WARNING WARNING WARNING"
+  } >&2
+}
+
 jlink_preflight_check()
 {
     # preflight check: do we have what we need?

modules/jlink/tests/features/jlink.feature

@@ -7,6 +7,7 @@ Scenario: Ensure jlinked builder is used to build the containerized application
        | S2I_ENABLE_JLINK    | true         |
        | QUARKUS_PACKAGE_TYPE| uber-jar     |
       Then run ls /tmp/jre in container and check its output for bin
+       And container log should contain Jlink integration is a Tech Preview feature.
 
 Scenario: Ensure S2I_ENABLE_JLINK is not set to true
       Given s2i build https://github.com/jboss-container-images/openjdk-test-applications from quarkus-quickstarts/getting-started-3.0.1.Final-nos2i

modules/s2i/bash/artifacts/usr/local/s2i/assemble

@@ -22,6 +22,7 @@ setup_java_app_and_lib
 if [ "$S2I_ENABLE_JLINK" = "true" ]; then
 
     source "${JBOSS_CONTAINER_JAVA_JLINK_MODULE}/preflight.sh"
+    jlink_techpreview_warning
     jlink_preflight_check
 
     source "${JBOSS_CONTAINER_JAVA_JLINK_MODULE}/mkdeps.sh"