Add pullPolicy option for image building

This commit adds a pullPolicy option to the configuration of the Maven
plugin spring-boot:build-image goal and the Gradle plugin bootBuildImage
task. The new option gives users control over pulling the builder image
and run image from a remote image registry to the local Docker daemon.

See gh-22736

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

@@ -42,6 +42,7 @@ import org.springframework.boot.buildpack.platform.build.BuildLog;
 import org.springframework.boot.buildpack.platform.build.BuildRequest;
 import org.springframework.boot.buildpack.platform.build.Builder;
 import org.springframework.boot.buildpack.platform.build.Creator;
+import org.springframework.boot.buildpack.platform.build.PullPolicy;
 import org.springframework.boot.buildpack.platform.docker.TotalProgressEvent;
 import org.springframework.boot.buildpack.platform.io.Owner;
 import org.springframework.boot.buildpack.platform.io.TarArchive;
@@ -123,6 +124,13 @@ public class BuildImageMojo extends AbstractPackagerMojo {
 	@Parameter(property = "spring-boot.build-image.runImage", readonly = true)
 	String runImage;
 
+	/**
+	 * Alias for {@link Image#pullPolicy} to support configuration via command-line
+	 * property.
+	 */
+	@Parameter(property = "spring-boot.build-image.pullPolicy", readonly = true)
+	PullPolicy pullPolicy;
+
 	@Override
 	public void execute() throws MojoExecutionException {
 		if (this.project.getPackaging().equals("pom")) {
@@ -160,6 +168,9 @@ public class BuildImageMojo extends AbstractPackagerMojo {
 		if (image.runImage == null && this.runImage != null) {
 			image.setRunImage(this.runImage);
 		}
+		if (image.pullPolicy == null && this.pullPolicy != null) {
+			image.setPullPolicy(this.pullPolicy);
+		}
 		return customize(image.getBuildRequest(this.project.getArtifact(), content));
 	}
 

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

@@ -22,6 +22,7 @@ import java.util.function.Function;
 import org.apache.maven.artifact.Artifact;
 
 import org.springframework.boot.buildpack.platform.build.BuildRequest;
+import org.springframework.boot.buildpack.platform.build.PullPolicy;
 import org.springframework.boot.buildpack.platform.docker.type.ImageName;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.io.Owner;
@@ -67,6 +68,11 @@ public class Image {
 	 */
 	boolean verboseLogging;
 
+	/**
+	 * If images should be pulled from a remote repository during image build.
+	 */
+	PullPolicy pullPolicy;
+
 	void setName(String name) {
 		this.name = name;
 	}
@@ -79,6 +85,10 @@ public class Image {
 		this.runImage = runImage;
 	}
 
+	public void setPullPolicy(PullPolicy pullPolicy) {
+		this.pullPolicy = pullPolicy;
+	}
+
 	BuildRequest getBuildRequest(Artifact artifact, Function<Owner, TarArchive> applicationContent) {
 		return customize(BuildRequest.of(getOrDeduceName(artifact), applicationContent));
 	}
@@ -103,6 +113,9 @@ public class Image {
 		}
 		request = request.withCleanCache(this.cleanCache);
 		request = request.withVerboseLogging(this.verboseLogging);
+		if (this.pullPolicy != null) {
+			request = request.withPullPolicy(this.pullPolicy);
+		}
 		return request;
 	}
 

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

@@ -26,6 +26,7 @@ import org.apache.maven.artifact.versioning.VersionRange;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.buildpack.platform.build.BuildRequest;
+import org.springframework.boot.buildpack.platform.build.PullPolicy;
 import org.springframework.boot.buildpack.platform.io.Owner;
 import org.springframework.boot.buildpack.platform.io.TarArchive;
 
@@ -63,6 +64,7 @@ class ImageTests {
 		assertThat(request.getEnv()).isEmpty();
 		assertThat(request.isCleanCache()).isFalse();
 		assertThat(request.isVerboseLogging()).isFalse();
+		assertThat(request.getPullPolicy()).isEqualTo(PullPolicy.ALWAYS);
 	}
 
 	@Test
@@ -105,6 +107,14 @@ class ImageTests {
 		assertThat(request.isVerboseLogging()).isTrue();
 	}
 
+	@Test
+	void getBuildRequestWhenHasPullPolicyUsesPullPolicy() {
+		Image image = new Image();
+		image.setPullPolicy(PullPolicy.NEVER);
+		BuildRequest request = image.getBuildRequest(createArtifact(), mockApplicationContent());
+		assertThat(request.getPullPolicy()).isEqualTo(PullPolicy.NEVER);
+	}
+
 	private Artifact createArtifact() {
 		return new DefaultArtifact("com.example", "my-app", VersionRange.createFromVersion("0.0.1-SNAPSHOT"), "compile",
 				"jar", null, new DefaultArtifactHandler());