Refactor ci script to choose test based on single cli arg

We prefer just passing a single cli argument that allows the script to
choose the corresponding gradle command from a preset list of
choices. For now, valid options are `packagingtests` or `tests`. The
script defaults to `tests` if no argument is supplied.

Original commit: elastic/x-pack-elasticsearch@f6315b1ad5

dev-tools/ci

@@ -11,28 +11,26 @@
 # `NVM_DIR` environment variable.
 #
 
-# Set the default gradle parameters for running tests
-gradleoptstring="--info check -Dtests.network=true -Dtests.badapples=true"
+# Turn on semi-strict mode
+set -e
+set -o pipefail
 
-while [ $# -ge 1 ]
-do
+# Set default test scenario, equivalent to passing the cli arg `tests`
+GRADLE_OPT_STRING="--info check -Dtests.network=true -Dtests.badapples=true"
+
+# Allow the user choose different test through a single cli arg
+if [ $# -ge 1 ]
+then
 key="$1"
 case $key in
-    -g|--gradleoptstring)
-        gradleoptstring="$2"
-        shift 2;;
-    -h|--help)
-        echo -e "Syntax:\n"
-        echo -e "$0 [-g|--gradleoptstring] \"override gradle parameters for tests\"\n"
-        exit 0;;
-    *)
-        echo "Unknown argument: $key";
-        exit 1;;
+    packagingtests)
+        GRADLE_OPT_STRING="--info -Pvagrant.boxes=all :x-plugins:qa:vagrant:packagingTest"
+        break;;
+    tests)
+        GRADLE_OPT_STRING="--info check -Dtests.network=true -Dtests.badapples=true"
+        break;;
 esac
-done
-
-# Turn on semi-strict mode
-set -e pipefail
+fi
 
 SCRIPT="$0"
 
@@ -109,6 +107,6 @@ set -xuf
 gradle --stacktrace clean
 
 # Actually run the tests
-gradle $gradleoptstring
+gradle $GRADLE_OPT_STRING
 
 # ~*~ shell-script-mode ~*~