Fetch changes and cache cloned repos

spring-cloud-release-tools-core/src/main/java/org/springframework/cloud/release/internal/Releaser.java

@@ -103,8 +103,9 @@ public class Releaser {
 		log.info("\n\nProject was successfully updated to [{}]", changedVersion);
 	}
 
-	public void buildProject(ProjectVersion versionFromScRelease) {
-		this.projectBuilder.build(versionFromScRelease);
+	public void buildProject(ProjectVersion versionFromScRelease,
+			ProjectBuilder.MavenProfile... profiles) {
+		this.projectBuilder.build(versionFromScRelease, profiles);
 		log.info("\nProject was successfully built");
 	}
 

spring-cloud-release-tools-core/src/main/java/org/springframework/cloud/release/internal/git/GitRepo.java

@@ -34,6 +34,7 @@ import com.jcraft.jsch.agentproxy.usocket.JNAUSocketFactory;
 import org.eclipse.jgit.api.CheckoutCommand;
 import org.eclipse.jgit.api.CloneCommand;
 import org.eclipse.jgit.api.CreateBranchCommand;
+import org.eclipse.jgit.api.FetchCommand;
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.api.ListBranchCommand;
 import org.eclipse.jgit.api.PushCommand;
@@ -43,6 +44,7 @@ import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.transport.CredentialsProvider;
+import org.eclipse.jgit.transport.FetchResult;
 import org.eclipse.jgit.transport.JschConfigSessionFactory;
 import org.eclipse.jgit.transport.OpenSshConfig;
 import org.eclipse.jgit.transport.RefSpec;
@@ -126,6 +128,20 @@ class GitRepo {
 		}
 	}
 
+	/**
+	 * Pull changes.
+	 */
+	void fetch() {
+		try {
+			log.info("Pull changes for repo [{}]", this.basedir);
+			fetch(this.basedir);
+			log.info("Successfully pulled the changes");
+		}
+		catch (Exception e) {
+			throw new IllegalStateException(e);
+		}
+	}
+
 	/**
 	 * Performs a commit.
 	 * @param message - commit message
@@ -282,6 +298,21 @@ class GitRepo {
 		return new File(destinationFolder, projectUrl.getHumanishName());
 	}
 
+	private FetchResult fetch(File projectDir) throws GitAPIException {
+		Git git = this.gitFactory.open(projectDir);
+		FetchCommand command = git.fetch();
+		try {
+			return command.call();
+		}
+		catch (GitAPIException e) {
+			deleteBaseDirIfExists();
+			throw e;
+		}
+		finally {
+			git.close();
+		}
+	}
+
 	private Ref checkoutBranch(File projectDir, String branch) throws GitAPIException {
 		Git git = this.gitFactory.open(projectDir);
 		CheckoutCommand command = git.checkout().setName(branch);

spring-cloud-release-tools-core/src/main/java/org/springframework/cloud/release/internal/git/ProjectGitHandler.java

@@ -19,6 +19,8 @@ package org.springframework.cloud.release.internal.git;
 import java.io.File;
 import java.nio.file.Files;
 import java.util.Arrays;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.eclipse.jgit.transport.URIish;
 import org.slf4j.Logger;
@@ -37,6 +39,8 @@ import org.springframework.util.StringUtils;
  */
 public class ProjectGitHandler implements ReleaserPropertiesAware {
 
+	private static final Map<URIish, File> CACHE = new ConcurrentHashMap<>();
+
 	private static final Logger log = LoggerFactory.getLogger(ProjectGitHandler.class);
 
 	private static final String MSG = "Bumping versions";
@@ -195,11 +199,22 @@ public class ProjectGitHandler implements ReleaserPropertiesAware {
 
 	File cloneProject(String url) {
 		try {
+			URIish urIish = new URIish(url);
+			// retrieve from cache and fetch if from cache
+			File clonedProject = CACHE.get(urIish);
+			if (clonedProject != null) {
+				log.info(
+						"Project has already been cloned. Will fetch the latest changes and return the cached location");
+				gitRepo(clonedProject).fetch();
+				return clonedProject;
+			}
 			File destinationDir = this.properties.getGit()
 					.getCloneDestinationDir() != null
 							? new File(this.properties.getGit().getCloneDestinationDir())
 							: Files.createTempDirectory("releaser").toFile();
-			return gitRepo(destinationDir).cloneProject(new URIish(url));
+			File clonedLocation = gitRepo(destinationDir).cloneProject(urIish);
+			CACHE.put(urIish, clonedLocation);
+			return clonedLocation;
 		}
 		catch (Exception e) {
 			throw new IllegalStateException(e);

spring-cloud-release-tools-core/src/main/java/org/springframework/cloud/release/internal/project/ProjectBuilder.java

@@ -44,6 +44,9 @@ import org.springframework.util.StringUtils;
  */
 public class ProjectBuilder implements ReleaserPropertiesAware {
 
+	/**
+	 * Enumeration over commonly used Maven profiles.
+	 */
 	public enum MavenProfile {
 
 		/**