Run cross-release SQL integration tests (#403)

* Run cross-release SQL integration tests

Run SQL integration tests across arbitrary schema and server
releases.

Refer to integration/README.md in this change for more information.

TESTED=Cloud build changes tested with cloud-build-local
       Used the published jars to test sqlIntegration task locally.

core/build.gradle

@@ -16,6 +16,7 @@ import java.lang.reflect.Constructor
 
 plugins {
   id 'java-library'
+  id 'maven-publish'
 }
 
 // Path to code generated by ad hoc tasks in this project. A separate path is
@@ -112,6 +113,11 @@ configurations {
   soy
   closureCompiler
 
+  // Published jars that are used for server/schema compatibility tests.
+  // See <a href="../integration/README.md">the integration project</a>
+  // for details.
+  nomulus_test
+
   // Exclude non-canonical servlet-api jars. Our AppEngine deployment uses
   // javax.servlet:servlet-api:2.5
   // For reasons we do not understand, marking the following dependencies as
@@ -814,6 +820,66 @@ test {
 createUberJar('nomulus', 'nomulus', 'google.registry.tools.RegistryTool')
 project.nomulus.dependsOn project(':third_party').jar
 
+// A jar with classes and resources from main sourceSet, excluding internal
+// data. See comments on configurations.nomulus_test above for details.
+task nomulusFossJar (type: Jar) {
+  archiveBaseName = 'nomulus'
+  archiveClassifier = 'public'
+  from (project.sourceSets.main.output) {
+    exclude 'google/registry/config/files/**'
+  }
+  from (project.sourceSets.main.output) {
+    include 'google/registry/config/files/default-config.yaml'
+    include 'google/registry/config/files/nomulus-config-unittest.yaml'
+  }
+}
+
+// An UberJar of registry test classes, resources and all dependencies.
+// See comments on configurations.nomulus_test above for details.
+// TODO(weiminyu): extract shareable code with root.ext.createUberJar
+task testUberJar (
+    type: com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar) {
+  mergeServiceFiles()
+  archiveBaseName = 'nomulus-tests'
+  archiveClassifier = 'alldeps'
+  zip64 = true
+  archiveVersion = ''
+  configurations = [project.configurations.testRuntimeClasspath]
+  from project.sourceSets.test.output
+  // Excludes signature files that accompany some dependency jars, like
+  // bonuncycastle. If they are present, only classes from those signed jars are
+  // made available to the class loader.
+  // see https://discuss.gradle.org/t/signing-a-custom-gradle-plugin-thats-downloaded-by-the-build-system-from-github/1365
+  exclude "META-INF/*.SF", "META-INF/*.DSA", "META-INF/*.RSA"
+  // Exclude SQL schema, which is a test dependency.
+  exclude 'sql/flyway/**'
+  // ShadowJar includes java source files when used on sourceSets.test.output.
+  // They are not needed.
+  exclude '**/*.java'
+}
+
+artifacts {
+  nomulus_test nomulusFossJar
+  nomulus_test testUberJar
+}
+
+publishing {
+  repositories {
+    maven {
+      url project.publish_repo
+    }
+  }
+  publications {
+    nomulusTestsPublication(MavenPublication) {
+      groupId 'google.registry'
+      artifactId 'nomulus_test'
+      version project.nomulus_version
+      artifact nomulusFossJar
+      artifact testUberJar
+    }
+  }
+}
+
 task buildToolImage(dependsOn: nomulus, type: Exec) {
   commandLine 'docker', 'build', '-t', 'nomulus-tool', '.'
 }

core/src/test/java/google/registry/model/transaction/JpaTransactionManagerRule.java

@@ -85,6 +85,7 @@ public class JpaTransactionManagerRule extends ExternalResource {
   private static final String POSTGRES_DB_NAME = "postgres";
 
   // Name of the optional property that specifies the root path of the golden schema.
+  // TODO(weiminyu): revert this. The :integration project offers a better solution.
   @VisibleForTesting
   static final String GOLDEN_SCHEMA_RESOURCE_ROOT_PROP = "sql_schema_resource_root";