Add docker-composed based test fixture for GCS (#48762)

Similarly to what has be done for Azure in #48636, this commit 
adds a new :test:fixtures:gcs-fixture project which provides two 
docker-compose based fixtures that emulate a Google Cloud 
Storage service.

Some code has been extracted from existing tests and placed 
into this new project so that it can be easily reused in other 
projects.

Author: tlrx

plugins/repository-gcs/build.gradle

@@ -52,6 +52,8 @@ dependencies {
   compile 'io.opencensus:opencensus-api:0.18.0'
   compile 'io.opencensus:opencensus-contrib-http-util:0.18.0'
   compile 'com.google.apis:google-api-services-storage:v1-rev20190426-1.28.0'
+
+  testCompile project(':test:fixtures:gcs-fixture')
 }
 
 dependencyLicenses {

plugins/repository-gcs/qa/google-cloud-storage/build.gradle

@@ -20,7 +20,6 @@
 
 import org.elasticsearch.gradle.MavenFilteringHack
 import org.elasticsearch.gradle.info.BuildParams
-import org.elasticsearch.gradle.test.AntFixture
 
 import java.nio.file.Files
 import java.security.KeyPair
@@ -30,12 +29,14 @@ import static org.elasticsearch.gradle.PropertyNormalization.IGNORE_VALUE
 
 apply plugin: 'elasticsearch.standalone-rest-test'
 apply plugin: 'elasticsearch.rest-test'
+apply plugin: 'elasticsearch.test.fixtures'
 
 // TODO think about flattening qa:google-cloud-storage project into parent
 dependencies {
     testCompile project(path: ':plugins:repository-gcs')
 }
 
+testFixtures.useFixture(':test:fixtures:gcs-fixture')
 boolean useFixture = false
 
 String gcsServiceAccount = System.getenv("google_storage_service_account")
@@ -45,7 +46,7 @@ String gcsBasePath = System.getenv("google_storage_base_path")
 File serviceAccountFile = null
 if (!gcsServiceAccount && !gcsBucket && !gcsBasePath) {
     serviceAccountFile = new File(project.buildDir, 'generated-resources/service_account_test.json')
-    gcsBucket = 'bucket_test'
+    gcsBucket = 'bucket'
     gcsBasePath = 'integration_test'
     useFixture = true
 } else if (!gcsServiceAccount || !gcsBucket || !gcsBasePath) {
@@ -58,12 +59,11 @@ def encodedCredentials = {
     Base64.encoder.encodeToString(Files.readAllBytes(serviceAccountFile.toPath()))
 }
 
-/** A task to start the GoogleCloudStorageFixture which emulates a Google Cloud Storage service **/
-task googleCloudStorageFixture(type: AntFixture) {
-    dependsOn testClasses
-    env 'CLASSPATH', "${ -> project.sourceSets.test.runtimeClasspath.asPath }"
-    executable = "${BuildParams.runtimeJavaHome}/bin/java"
-    args 'org.elasticsearch.repositories.gcs.GoogleCloudStorageFixture', baseDir, 'bucket_test'
+def fixtureAddress = { fixture ->
+    assert useFixture : 'closure should not be used without a fixture'
+    int ephemeralPort = project(':test:fixtures:gcs-fixture').postProcessFixture.ext."test.fixtures.${fixture}.tcp.80"
+    assert ephemeralPort > 0
+    'http://127.0.0.1:' + ephemeralPort
 }
 
 /** A service account file that points to the Google Cloud Storage service emulated by the fixture **/
@@ -87,6 +87,19 @@ task createServiceAccountFile() {
 }
 
 task thirdPartyTest (type: Test) {
+    if (useFixture) {
+        thirdPartyTest.dependsOn createServiceAccountFile
+        nonInputProperties.systemProperty 'test.google.endpoint', "${ -> fixtureAddress('gcs-fixture-third-party') }"
+        nonInputProperties.systemProperty 'test.google.tokenURI', "${ -> fixtureAddress('gcs-fixture-third-party') }/o/oauth2/token"
+
+        gradle.taskGraph.whenReady {
+            if (it.hasTask(gcsThirdPartyTests)) {
+                throw new IllegalStateException("Tried to run third party tests but not all of the necessary environment variables " +
+                        "'google_storage_service_account', 'google_storage_bucket', 'google_storage_base_path' are set.")
+            }
+        }
+    }
+
     include '**/GoogleCloudStorageThirdPartyTests.class'
     systemProperty 'tests.security.manager', false
     systemProperty 'test.google.bucket', gcsBucket
@@ -98,32 +111,6 @@ task gcsThirdPartyTests {
     dependsOn check
 }
 
-if (useFixture) {
-    // TODO think about running the fixture in the same JVM as tests
-    thirdPartyTest.dependsOn createServiceAccountFile, googleCloudStorageFixture
-    thirdPartyTest.finalizedBy googleCloudStorageFixture.getStopTask()
-
-    def fixtureEndpoint = {
-        "http://${googleCloudStorageFixture.addressAndPort}"
-    }
-
-    def tokenURI = {
-        "http://${googleCloudStorageFixture.addressAndPort}/o/oauth2/token"
-    }
-
-    thirdPartyTest {
-        nonInputProperties.systemProperty 'test.google.endpoint', "${ -> fixtureEndpoint.call() }"
-        nonInputProperties.systemProperty 'test.google.tokenURI', "${ -> tokenURI.call() }"
-    }
-
-    gradle.taskGraph.whenReady {
-        if (it.hasTask(gcsThirdPartyTests)) {
-            throw new IllegalStateException("Tried to run third party tests but not all of the necessary environment variables 'google_storage_service_account', " +
-                    "'google_storage_bucket', 'google_storage_base_path' are set.")
-        }
-    }
-}
-
 integTest.mustRunAfter(thirdPartyTest)
 check.dependsOn thirdPartyTest
 
@@ -147,10 +134,10 @@ testClusters.integTest {
     keystore 'gcs.client.integration_test.credentials_file', serviceAccountFile, IGNORE_VALUE
 
     if (useFixture) {
-        tasks.integTest.dependsOn createServiceAccountFile, googleCloudStorageFixture
+        tasks.integTest.dependsOn createServiceAccountFile
         /* Use a closure on the string to delay evaluation until tests are executed */
-        setting 'gcs.client.integration_test.endpoint', { "http://${googleCloudStorageFixture.addressAndPort}" }, IGNORE_VALUE
-        setting 'gcs.client.integration_test.token_uri', { "http://${googleCloudStorageFixture.addressAndPort}/o/oauth2/token" }, IGNORE_VALUE
+        setting 'gcs.client.integration_test.endpoint', { "${ -> fixtureAddress('gcs-fixture') }" }, IGNORE_VALUE
+        setting 'gcs.client.integration_test.token_uri', { "${ -> fixtureAddress('gcs-fixture') }/o/oauth2/token" }, IGNORE_VALUE
     } else {
         println "Using an external service to test the repository-gcs plugin"
     }