Use gradle and bundled jruby for acceptance tests orchestration

build.gradle

@@ -752,7 +752,19 @@ tasks.register("runIntegrationTests") {
     shouldRunAfter ":logstash-core:test"
 }
 
+tasks.register("installAcceptanceTestGems", Exec) {
+    dependsOn bootstrap
+    inputs.files file("${projectDir}/qa/Gemfile")
+    outputs.file("${projectDir}/qa/Gemfile.lock")
+    workingDir "${projectDir}/qa"
+    commandLine "${projectDir}/vendor/jruby/bin/jruby", "-S", "bundle", "install", "--path", "vendor/bundle"
+}
 
+tasks.register("runAcceptanceTests", Exec) {
+    dependsOn installAcceptanceTestGems
+    workingDir "${projectDir}/qa"
+    commandLine "${projectDir}/vendor/jruby/bin/jruby", "-S", "bundle", "exec", "rake", "qa:acceptance:all"
+}
 
 tasks.register("generateLicenseReport", JavaExec) {
     dependsOn generateLicenseReportInputs

ci/acceptance_tests.sh

@@ -52,11 +52,5 @@ else
   esac
 fi
 
-echo "--- Acceptance: Installing dependencies"
-cd $QA_DIR
-bundle install
-
 echo "--- Acceptance: Running the tests"
-# TODO: figure out how to encapsulate all this in gradle or at least ensure the bundler
-# used here ends up using the runtime managed with LS. 
-rake qa:acceptance:all
+./gradlew runAcceptanceTests