[#2269] Keep containers image and version in docker files

We are trying to achieve two things:
* Make it possible for dependabot to upgrade the containers
  automatically
* Collect the image and version of the containers we use for testing in
  one place

Note that the test suite will still create and start the containers
programmatically, but it will read the first FROM line in each Dockerfile
to extract the image and version to use. It will ignore everything else.

My initial plan was to configure each container using the Dockerfile
directly, but I prefer to reuse the exsisting Testcontainers classes for
each database (for example, PostgreSQLContainer) because they contain
out-of-the-box configuration that I would need to copy somewhere else.

In any case, this is a good starting point and we can improve it later.

Author: DavideD

build.gradle

@@ -52,6 +52,12 @@ subprojects {
         options.encoding = 'UTF-8'
     }
 
+    // Configure test tasks for all subprojects
+    tasks.withType( Test ).configureEach {
+        // Set the project root for finding Docker files - available to all modules
+        systemProperty 'hibernate.reactive.project.root', rootProject.projectDir.absolutePath
+    }
+
     if ( !gradle.ext.javaToolchainEnabled ) {
         sourceCompatibility = JavaVersion.toVersion( gradle.ext.baselineJavaVersion )
         targetCompatibility = JavaVersion.toVersion( gradle.ext.baselineJavaVersion )

hibernate-reactive-core/src/test/java/org/hibernate/reactive/containers/CockroachDBDatabase.java

@@ -12,7 +12,7 @@
 import org.testcontainers.containers.CockroachContainer;
 import org.testcontainers.containers.Container;
 
-import static org.hibernate.reactive.containers.DockerImage.imageName;
+import static org.hibernate.reactive.containers.DockerImage.fromDockerfile;
 
 class CockroachDBDatabase extends PostgreSQLDatabase {
 
@@ -25,7 +25,7 @@ class CockroachDBDatabase extends PostgreSQLDatabase {
 	 * TIP: To reuse the same containers across multiple runs, set `testcontainers.reuse.enable=true` in a file located
 	 * at `$HOME/.testcontainers.properties` (create the file if it does not exist).
 	 */
-	public static final CockroachContainer cockroachDb = new CockroachContainer( imageName( "cockroachdb/cockroach", "v24.3.13" ) )
+	public static final CockroachContainer cockroachDb = new CockroachContainer( fromDockerfile( "cockroachdb" ) )
 			// Username, password and database are not supported by test container at the moment
 			// Testcontainers will use a database named 'postgres' and the 'root' user
 			.withReuse( true );

hibernate-reactive-core/src/test/java/org/hibernate/reactive/containers/DB2Database.java

@@ -28,7 +28,7 @@
 
 import org.testcontainers.containers.Db2Container;
 
-import static org.hibernate.reactive.containers.DockerImage.imageName;
+import static org.hibernate.reactive.containers.DockerImage.fromDockerfile;
 
 class DB2Database implements TestableDatabase {
 
@@ -87,7 +87,7 @@ class DB2Database implements TestableDatabase {
 	 * TIP: To reuse the same containers across multiple runs, set `testcontainers.reuse.enable=true` in a file located
 	 * at `$HOME/.testcontainers.properties` (create the file if it does not exist).
 	 */
-	static final Db2Container db2 = new Db2Container( imageName( "icr.io", "db2_community/db2", "12.1.0.0" ) )
+	static final Db2Container db2 = new Db2Container( fromDockerfile( "db2" ) )
 			.withUsername( DatabaseConfiguration.USERNAME )
 			.withPassword( DatabaseConfiguration.PASSWORD )
 			.withDatabaseName( DatabaseConfiguration.DB_NAME )

hibernate-reactive-core/src/test/java/org/hibernate/reactive/containers/DockerImage.java

@@ -5,10 +5,17 @@
  */
 package org.hibernate.reactive.containers;
 
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
 import org.testcontainers.utility.DockerImageName;
 
+
 /**
- * A utility class with methods to generate {@link DockerImageName} for testcontainers.
+ * A utility class with methods to generate a {@link DockerImageName} for Testcontainers.
  * <p>
  * Testcontainers might not work if the image required is available in multiple different registries (for example when
  * using podman instead of docker).
@@ -17,15 +24,103 @@
  */
 public final class DockerImage {
 
-	public static final String DEFAULT_REGISTRY = "docker.io";
+	/**
+	 * The absolute path of the project root that we have set in Gradle.
+	 */
+	private static final String PROJECT_ROOT = System.getProperty( "hibernate.reactive.project.root" );
+
+	/**
+	 * The path to the directory containing all the Dockerfile files
+	 */
+	private static final Path DOCKERFILE_DIR_PATH = Path.of( PROJECT_ROOT ).resolve( "tooling" ).resolve( "docker" );
 
-	public static DockerImageName imageName(String image, String version) {
-		return imageName( DEFAULT_REGISTRY, image, version );
+	/**
+	 * Extract the image name and version from the first FROM instruction in the Dockerfile.
+	 * Note that everything else is ignored.
+	 */
+	public static DockerImageName fromDockerfile(String databaseName) {
+		try {
+			final ImageInformation imageInformation = readFromInstruction( databaseName.toLowerCase() );
+			return imageName( imageInformation.getRegistry(), imageInformation.getImage(), imageInformation.getVersion() );
+		}
+		catch (IOException e) {
+			throw new RuntimeException( e );
+		}
 	}
 
 	public static DockerImageName imageName(String registry, String image, String version) {
 		return DockerImageName
 				.parse( registry + "/" + image + ":" + version )
 				.asCompatibleSubstituteFor( image );
 	}
+
+	private static class ImageInformation {
+		private final String registry;
+		private final String image;
+		private final String version;
+
+		public ImageInformation(String fullImageInfo) {
+			// FullImageInfo pattern: <registry>/<image>:<version>
+			// For example: "docker.io/cockroachdb/cockroach:v24.3.13" becomes registry = "docker.io", image = "cockroachdb/cockroach", version = "v24.3.13"
+			final int registryEndPos = fullImageInfo.indexOf( '/' );
+			final int imageEndPos = fullImageInfo.lastIndexOf( ':' );
+			this.registry = fullImageInfo.substring( 0, registryEndPos );
+			this.image = fullImageInfo.substring( registryEndPos + 1, imageEndPos );
+			this.version = fullImageInfo.substring( imageEndPos + 1 );
+		}
+
+		public String getRegistry() {
+			return registry;
+		}
+
+		public String getImage() {
+			return image;
+		}
+
+		public String getVersion() {
+			return version;
+		}
+
+		@Override
+		public String toString() {
+			return registry + "/" + image + ":" + version;
+		}
+	}
+
+	private static Path dockerFilePath(String database) {
+		// Get project root from system property set by Gradle, with fallback
+		return DOCKERFILE_DIR_PATH.resolve( database.toLowerCase() + ".Dockerfile" );
+	}
+
+	private static ImageInformation readFromInstruction(String database) throws IOException {
+		return readFromInstruction( dockerFilePath( database ) );
+	}
+
+	/**
+	 * Read a Dockerfile and extract the first FROM instruction.
+	 *
+	 * @param dockerfilePath path to the Dockerfile
+	 * @return the first FROM instruction found, or empty if none found
+	 * @throws IOException if the file cannot be read
+	 */
+	private static ImageInformation readFromInstruction(Path dockerfilePath) throws IOException {
+		if ( !Files.exists( dockerfilePath ) ) {
+			throw new FileNotFoundException( "Dockerfile not found: " + dockerfilePath );
+		}
+
+		List<String> lines = Files.readAllLines( dockerfilePath );
+		for ( String line : lines ) {
+			// Skip comments and empty lines
+			String trimmedLine = line.trim();
+			if ( trimmedLine.isEmpty() || trimmedLine.startsWith( "#" ) ) {
+				continue;
+			}
+
+			if ( trimmedLine.startsWith( "FROM " ) ) {
+				return new ImageInformation( trimmedLine.substring( "FROM ".length() ) );
+			}
+		}
+
+		throw new IOException( " Missing FROM instruction in " + dockerfilePath );
+	}
 }

hibernate-reactive-core/src/test/java/org/hibernate/reactive/containers/MSSQLServerDatabase.java

@@ -28,7 +28,7 @@
 
 import org.testcontainers.containers.MSSQLServerContainer;
 
-import static org.hibernate.reactive.containers.DockerImage.imageName;
+import static org.hibernate.reactive.containers.DockerImage.fromDockerfile;
 
 /**
  * The JDBC driver syntax is:
@@ -96,7 +96,7 @@ class MSSQLServerDatabase implements TestableDatabase {
 	 * TIP: To reuse the same containers across multiple runs, set `testcontainers.reuse.enable=true` in a file located
 	 * at `$HOME/.testcontainers.properties` (create the file if it does not exist).
 	 */
-	public static final MSSQLServerContainer<?> mssqlserver = new MSSQLServerContainer<>( imageName( "mcr.microsoft.com", "mssql/server", "2022-latest" ) )
+	public static final MSSQLServerContainer<?> mssqlserver = new MSSQLServerContainer<>( fromDockerfile( "sqlserver" ) )
 			.acceptLicense()
 			.withPassword( PASSWORD )
 			.withReuse( true );

hibernate-reactive-core/src/test/java/org/hibernate/reactive/containers/MariaDatabase.java

@@ -13,7 +13,7 @@
 
 import org.testcontainers.containers.MariaDBContainer;
 
-import static org.hibernate.reactive.containers.DockerImage.imageName;
+import static org.hibernate.reactive.containers.DockerImage.fromDockerfile;
 
 class MariaDatabase extends MySQLDatabase {
 
@@ -36,7 +36,7 @@ class MariaDatabase extends MySQLDatabase {
 	 * TIP: To reuse the same containers across multiple runs, set `testcontainers.reuse.enable=true` in a file located
 	 * at `$HOME/.testcontainers.properties` (create the file if it does not exist).
 	 */
-	public static final MariaDBContainer<?> maria = new MariaDBContainer<>( imageName( "mariadb", "11.7.2" ) )
+	public static final MariaDBContainer<?> maria = new MariaDBContainer<>( fromDockerfile( "maria" ) )
 			.withUsername( DatabaseConfiguration.USERNAME )
 			.withPassword( DatabaseConfiguration.PASSWORD )
 			.withDatabaseName( DatabaseConfiguration.DB_NAME )

hibernate-reactive-core/src/test/java/org/hibernate/reactive/containers/MySQLDatabase.java

@@ -5,7 +5,7 @@
  */
 package org.hibernate.reactive.containers;
 
-import static org.hibernate.reactive.containers.DockerImage.imageName;
+import static org.hibernate.reactive.containers.DockerImage.fromDockerfile;
 
 import java.io.Serializable;
 import java.math.BigDecimal;
@@ -87,7 +87,7 @@ class MySQLDatabase implements TestableDatabase {
 	 * TIP: To reuse the same containers across multiple runs, set `testcontainers.reuse.enable=true` in a file located
 	 * at `$HOME/.testcontainers.properties` (create the file if it does not exist).
 	 */
-	public static final MySQLContainer<?> mysql = new MySQLContainer<>( imageName( "mysql", "9.2.0") )
+	public static final MySQLContainer<?> mysql = new MySQLContainer<>( fromDockerfile( "mysql" ) )
 			.withUsername( DatabaseConfiguration.USERNAME )
 			.withPassword( DatabaseConfiguration.PASSWORD )
 			.withDatabaseName( DatabaseConfiguration.DB_NAME )

hibernate-reactive-core/src/test/java/org/hibernate/reactive/containers/OracleDatabase.java

@@ -29,7 +29,7 @@
 
 import org.testcontainers.containers.OracleContainer;
 
-import static org.hibernate.reactive.containers.DockerImage.imageName;
+import static org.hibernate.reactive.containers.DockerImage.fromDockerfile;
 
 /**
  * Connection string for Oracle thin should be something like:
@@ -88,9 +88,7 @@ class OracleDatabase implements TestableDatabase {
 		}
 	}
 
-	public static final OracleContainer oracle = new OracleContainer(
-				imageName( "gvenzl/oracle-free", "23-slim-faststart" )
-					.asCompatibleSubstituteFor( "gvenzl/oracle-xe" ) )
+	public static final OracleContainer oracle = new OracleContainer( fromDockerfile( "oracle" ).asCompatibleSubstituteFor( "gvenzl/oracle-xe" ) )
 			.withUsername( DatabaseConfiguration.USERNAME )
 			.withPassword( DatabaseConfiguration.PASSWORD )
 			.withDatabaseName( DatabaseConfiguration.DB_NAME )

hibernate-reactive-core/src/test/java/org/hibernate/reactive/containers/PostgreSQLDatabase.java

@@ -5,8 +5,6 @@
  */
 package org.hibernate.reactive.containers;
 
-import static org.hibernate.reactive.containers.DockerImage.imageName;
-
 import java.io.Serializable;
 import java.math.BigDecimal;
 import java.math.BigInteger;
@@ -30,9 +28,11 @@
 
 import org.testcontainers.containers.PostgreSQLContainer;
 
+import static org.hibernate.reactive.containers.DockerImage.fromDockerfile;
+
 class PostgreSQLDatabase implements TestableDatabase {
 
-	public static PostgreSQLDatabase INSTANCE = new PostgreSQLDatabase();
+	public static final PostgreSQLDatabase INSTANCE = new PostgreSQLDatabase();
 
 	private static Map<Class<?>, String> expectedDBTypeForClass = new HashMap<>();
 
@@ -87,7 +87,7 @@ class PostgreSQLDatabase implements TestableDatabase {
 	 * TIP: To reuse the same containers across multiple runs, set `testcontainers.reuse.enable=true` in a file located
 	 * at `$HOME/.testcontainers.properties` (create the file if it does not exist).
 	 */
-	public static final PostgreSQLContainer<?> postgresql = new PostgreSQLContainer<>( imageName( "postgres", "17.5" ) )
+	public static final PostgreSQLContainer<?> postgresql = new PostgreSQLContainer<>( fromDockerfile( "postgresql" ) )
 			.withUsername( DatabaseConfiguration.USERNAME )
 			.withPassword( DatabaseConfiguration.PASSWORD )
 			.withDatabaseName( DatabaseConfiguration.DB_NAME )

integration-tests/bytecode-enhancements-it/src/test/java/org/hibernate/reactive/it/BaseReactiveIT.java

@@ -51,9 +51,7 @@ public abstract class BaseReactiveIT {
 	// These properties are in DatabaseConfiguration in core
 	public static final boolean USE_DOCKER = Boolean.getBoolean( "docker" );
 
-	public static final DockerImageName IMAGE_NAME = DockerImageName
-			.parse( "docker.io/postgres:17.5" )
-			.asCompatibleSubstituteFor( "postgres" );
+	public static final DockerImageName IMAGE_NAME = DockerImage.fromDockerfile( "postgresql" );
 
 	public static final String USERNAME = "hreact";
 	public static final String PASSWORD = "hreact";