Simplify support for pushing images to unauthenticated registries

This commit removes the requirement that `docker.publishRegistry`
configuration must be provided when an image is published by the Gradle
or Maven plugin.

Fixes gh-28844

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/configuration/DockerConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -90,4 +90,9 @@ public final class DockerConfiguration {
 				new DockerRegistryUserAuthentication(username, password, url, email));
 	}
 
+	public DockerConfiguration withEmptyPublishRegistryAuthentication() {
+		return new DockerConfiguration(this.host, this.builderAuthentication,
+				new DockerRegistryUserAuthentication("", "", "", ""));
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/asciidoc/packaging-oci-image.adoc

@@ -368,7 +368,10 @@ An OCI image containing a https://buildpacks.io/docs/buildpack-author-guide/pack
 
 [[build-image.examples.publish]]
 === Image Publishing
-The generated image can be published to a Docker registry by enabling a `publish` option and configuring authentication for the registry using `docker.publishRegistry` properties.
+The generated image can be published to a Docker registry by enabling a `publish` option.
+
+If the Docker registry requires authentication, the credentials can be configured using `docker.publishRegistry` properties.
+If the Docker registry does not require authentication, the `docker.publishRegistry` configuration can be omitted.
 
 [source,groovy,indent=0,subs="verbatim,attributes",role="primary"]
 .Groovy

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootBuildImage.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,7 +25,6 @@ import java.util.stream.Collectors;
 import groovy.lang.Closure;
 import org.gradle.api.Action;
 import org.gradle.api.DefaultTask;
-import org.gradle.api.GradleException;
 import org.gradle.api.JavaVersion;
 import org.gradle.api.Project;
 import org.gradle.api.Task;
@@ -605,11 +604,6 @@ public class BootBuildImage extends DefaultTask {
 	}
 
 	private BuildRequest customizePublish(BuildRequest request) {
-		boolean publishRegistryAuthNotConfigured = this.docker == null || this.docker.getPublishRegistry() == null
-				|| this.docker.getPublishRegistry().hasEmptyAuth();
-		if (this.publish && publishRegistryAuthNotConfigured) {
-			throw new GradleException("Publishing an image requires docker.publishRegistry to be configured");
-		}
 		request = request.withPublish(this.publish);
 		return request;
 	}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/DockerSpec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -179,7 +179,7 @@ public class DockerSpec {
 
 	private DockerConfiguration customizePublishAuthentication(DockerConfiguration dockerConfiguration) {
 		if (this.publishRegistry == null || this.publishRegistry.hasEmptyAuth()) {
-			return dockerConfiguration;
+			return dockerConfiguration.withEmptyPublishRegistryAuthentication();
 		}
 		if (this.publishRegistry.hasTokenAuth() && !this.publishRegistry.hasUserAuth()) {
 			return dockerConfiguration.withPublishRegistryTokenAuthentication(this.publishRegistry.getToken());

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/BootBuildImageIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -313,15 +313,6 @@ class BootBuildImageIntegrationTests {
 				.containsPattern("example/Invalid-Image-Name");
 	}
 
-	@TestTemplate
-	void failsWithPublishMissingPublishRegistry() throws IOException {
-		writeMainClass();
-		writeLongNameResource();
-		BuildResult result = this.gradleBuild.buildAndFail("bootBuildImage", "--publishImage");
-		assertThat(result.task(":bootBuildImage").getOutcome()).isEqualTo(TaskOutcome.FAILED);
-		assertThat(result.getOutput()).contains("requires docker.publishRegistry");
-	}
-
 	@TestTemplate
 	void failsWithBuildpackNotInBuilder() throws IOException {
 		writeMainClass();

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/BootBuildImageTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,7 +21,6 @@ import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
-import org.gradle.api.GradleException;
 import org.gradle.api.JavaVersion;
 import org.gradle.api.Project;
 import org.junit.jupiter.api.BeforeEach;
@@ -36,7 +35,6 @@ import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.gradle.junit.GradleProjectBuilder;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
 /**
  * Tests for {@link BootBuildImage}.
@@ -189,13 +187,6 @@ class BootBuildImageTests {
 		assertThat(this.buildImage.createRequest().isPublish()).isFalse();
 	}
 
-	@Test
-	void whenPublishIsEnabledWithoutPublishRegistryThenExceptionIsThrown() {
-		this.buildImage.setPublish(true);
-		assertThatExceptionOfType(GradleException.class).isThrownBy(this.buildImage::createRequest)
-				.withMessageContaining("Publishing an image requires docker.publishRegistry to be configured");
-	}
-
 	@Test
 	void whenNoBuilderIsConfiguredThenRequestHasDefaultBuilder() {
 		assertThat(this.buildImage.createRequest().getBuilder().getName()).isEqualTo("paketobuildpacks/builder");

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/DockerSpecTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -37,9 +37,12 @@ class DockerSpecTests {
 	@Test
 	void asDockerConfigurationWithDefaults() {
 		DockerSpec dockerSpec = new DockerSpec();
-		assertThat(dockerSpec.asDockerConfiguration().getHost()).isNull();
+		DockerConfiguration dockerConfiguration = dockerSpec.asDockerConfiguration();
-		assertThat(dockerSpec.asDockerConfiguration().getBuilderRegistryAuthentication()).isNull();
+		assertThat(dockerConfiguration.getHost()).isNull();
-		assertThat(dockerSpec.asDockerConfiguration().getPublishRegistryAuthentication()).isNull();
+		assertThat(dockerConfiguration.getBuilderRegistryAuthentication()).isNull();
+		assertThat(decoded(dockerConfiguration.getPublishRegistryAuthentication().getAuthHeader()))
+				.contains("\"username\" : \"\"").contains("\"password\" : \"\"").contains("\"email\" : \"\"")
+				.contains("\"serveraddress\" : \"\"");
 	}
 
 	@Test
@@ -54,7 +57,9 @@ class DockerSpecTests {
 		assertThat(host.isSecure()).isEqualTo(true);
 		assertThat(host.getCertificatePath()).isEqualTo("/tmp/ca-cert");
 		assertThat(dockerSpec.asDockerConfiguration().getBuilderRegistryAuthentication()).isNull();
-		assertThat(dockerSpec.asDockerConfiguration().getPublishRegistryAuthentication()).isNull();
+		assertThat(decoded(dockerConfiguration.getPublishRegistryAuthentication().getAuthHeader()))
+				.contains("\"username\" : \"\"").contains("\"password\" : \"\"").contains("\"email\" : \"\"")
+				.contains("\"serveraddress\" : \"\"");
 	}
 
 	@Test
@@ -67,7 +72,9 @@ class DockerSpecTests {
 		assertThat(host.isSecure()).isEqualTo(false);
 		assertThat(host.getCertificatePath()).isNull();
 		assertThat(dockerSpec.asDockerConfiguration().getBuilderRegistryAuthentication()).isNull();
-		assertThat(dockerSpec.asDockerConfiguration().getPublishRegistryAuthentication()).isNull();
+		assertThat(decoded(dockerConfiguration.getPublishRegistryAuthentication().getAuthHeader()))
+				.contains("\"username\" : \"\"").contains("\"password\" : \"\"").contains("\"email\" : \"\"")
+				.contains("\"serveraddress\" : \"\"");
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootBuildImageRegistryIntegrationTests.gradle

@@ -7,11 +7,6 @@ sourceCompatibility = '1.8'
 targetCompatibility = '1.8'
 
 bootBuildImage {
+	builder = "projects.registry.vmware.com/springboot/spring-boot-cnb-builder:0.0.1"
 	publish = true
-	docker {
-		publishRegistry {
-			username = "user"
-			password = "secret"
-		}
-	}
 }

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/docs/asciidoc/packaging-oci-image.adoc

@@ -338,7 +338,10 @@ An OCI image containing a https://buildpacks.io/docs/buildpack-author-guide/pack
 
 [[build-image.examples.publish]]
 === Image Publishing
-The generated image can be published to a Docker registry by enabling a `publish` option and configuring authentication for the registry using `docker.publishRegistry` parameters.
+The generated image can be published to a Docker registry by enabling a `publish` option.
+
+If the Docker registry requires authentication, the credentials can be configured using `docker.publishRegistry` parameters.
+If the Docker registry does not require authentication, the `docker.publishRegistry` configuration can be omitted.
 
 [source,xml,indent=0,subs="verbatim,attributes",tabsize=4]
 ----

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/BuildImageTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -330,12 +330,6 @@ class BuildImageTests extends AbstractArchiveIntegrationTests {
 						(project) -> assertThat(buildLog(project)).contains("Error packaging archive for image"));
 	}
 
-	@TestTemplate
-	void failsWhenPublishWithoutPublishRegistryConfigured(MavenBuild mavenBuild) {
-		mavenBuild.project("build-image").goals("package").systemProperty("spring-boot.build-image.publish", "true")
-				.executeAndFail((project) -> assertThat(buildLog(project)).contains("requires docker.publishRegistry"));
-	}
-
 	@TestTemplate
 	void failsWhenBuilderFails(MavenBuild mavenBuild) {
 		mavenBuild.project("build-image-builder-error").goals("package")

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/build-image-publish/pom.xml

@@ -23,14 +23,9 @@
 						</goals>
 						<configuration>
 							<image>
+								<builder>projects.registry.vmware.com/springboot/spring-boot-cnb-builder:0.0.1</builder>
 								<publish>true</publish>
 							</image>
-							<docker>
-								<publishRegistry>
-									<username>user</username>
-									<password>secret</password>
-								</publishRegistry>
-							</docker>
 						</configuration>
 					</execution>
 				</executions>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/BuildImageMojo.java

@@ -224,7 +224,7 @@ public class BuildImageMojo extends AbstractPackagerMojo {
 		Libraries libraries = getLibraries(Collections.emptySet());
 		try {
 			DockerConfiguration dockerConfiguration = (this.docker != null) ? this.docker.asDockerConfiguration()
-					: null;
+					: new Docker().asDockerConfiguration();
 			BuildRequest request = getBuildRequest(libraries);
 			Builder builder = new Builder(new MojoBuildLog(this::getLog), dockerConfiguration);
 			builder.build(request);
@@ -234,7 +234,7 @@ public class BuildImageMojo extends AbstractPackagerMojo {
 		}
 	}
 
-	private BuildRequest getBuildRequest(Libraries libraries) throws MojoExecutionException {
+	private BuildRequest getBuildRequest(Libraries libraries) {
 		ImagePackager imagePackager = new ImagePackager(getArchiveFile(), getBackupFile());
 		Function<Owner, TarArchive> content = (owner) -> getApplicationContent(owner, libraries, imagePackager);
 		Image image = (this.image != null) ? this.image : new Image();
@@ -259,17 +259,9 @@ public class BuildImageMojo extends AbstractPackagerMojo {
 		if (image.network == null && this.network != null) {
 			image.setNetwork(this.network);
 		}
-		if (image.publish != null && image.publish && publishRegistryNotConfigured()) {
-			throw new MojoExecutionException("Publishing an image requires docker.publishRegistry to be configured");
-		}
 		return customize(image.getBuildRequest(this.project.getArtifact(), content));
 	}
 
-	private boolean publishRegistryNotConfigured() {
-		return this.docker == null || this.docker.getPublishRegistry() == null
-				|| this.docker.getPublishRegistry().isEmpty();
-	}
-
 	private TarArchive getApplicationContent(Owner owner, Libraries libraries, ImagePackager imagePackager) {
 		ImagePackager packager = getConfiguredPackager(() -> imagePackager);
 		return new PackagedTarArchive(owner, libraries, packager);

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/Docker.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -146,7 +146,7 @@ public class Docker {
 
 	private DockerConfiguration customizePublishAuthentication(DockerConfiguration dockerConfiguration) {
 		if (this.publishRegistry == null || this.publishRegistry.isEmpty()) {
-			return dockerConfiguration;
+			return dockerConfiguration.withEmptyPublishRegistryAuthentication();
 		}
 		if (this.publishRegistry.hasTokenAuth() && !this.publishRegistry.hasUserAuth()) {
 			return dockerConfiguration.withPublishRegistryTokenAuthentication(this.publishRegistry.getToken());

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/test/java/org/springframework/boot/maven/DockerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,9 +36,12 @@ class DockerTests {
 	@Test
 	void asDockerConfigurationWithDefaults() {
 		Docker docker = new Docker();
-		assertThat(docker.asDockerConfiguration().getHost()).isNull();
+		DockerConfiguration dockerConfiguration = docker.asDockerConfiguration();
-		assertThat(docker.asDockerConfiguration().getBuilderRegistryAuthentication()).isNull();
+		assertThat(dockerConfiguration.getHost()).isNull();
-		assertThat(docker.asDockerConfiguration().getPublishRegistryAuthentication()).isNull();
+		assertThat(dockerConfiguration.getBuilderRegistryAuthentication()).isNull();
+		assertThat(decoded(dockerConfiguration.getPublishRegistryAuthentication().getAuthHeader()))
+				.contains("\"username\" : \"\"").contains("\"password\" : \"\"").contains("\"email\" : \"\"")
+				.contains("\"serveraddress\" : \"\"");
 	}
 
 	@Test
@@ -53,7 +56,9 @@ class DockerTests {
 		assertThat(host.isSecure()).isEqualTo(true);
 		assertThat(host.getCertificatePath()).isEqualTo("/tmp/ca-cert");
 		assertThat(docker.asDockerConfiguration().getBuilderRegistryAuthentication()).isNull();
-		assertThat(docker.asDockerConfiguration().getPublishRegistryAuthentication()).isNull();
+		assertThat(decoded(dockerConfiguration.getPublishRegistryAuthentication().getAuthHeader()))
+				.contains("\"username\" : \"\"").contains("\"password\" : \"\"").contains("\"email\" : \"\"")
+				.contains("\"serveraddress\" : \"\"");
 	}
 
 	@Test