feat (jkube-kit/build/service/buildpacks) : Add BuildPackCliDownloader

- Add a class BuildPackCliDownloader whose responsibility would be
  downloading pack binary
- In order to check whether already downloaded binary is working, add
  step for executing `pack --version` command

Signed-off-by: Rohan Kumar <rohaan@redhat.com>

jkube-kit/build/service/buildpacks/pom.xml

@@ -29,5 +29,43 @@
   <name>JKube Kit :: Build :: Service :: Buildpacks</name>
 
   <dependencies>
+    <dependency>
+      <groupId>org.eclipse.jkube</groupId>
+      <artifactId>jkube-kit-build-api</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.eclipse.jkube</groupId>
+      <artifactId>jkube-kit-common</artifactId>
+      <scope>test</scope>
+      <type>test-jar</type>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.assertj</groupId>
+      <artifactId>assertj-core</artifactId>
+    </dependency>
   </dependencies>
+
+  <build>
+    <resources>
+      <!-- Copy over default pack properties defined above -->
+      <resource>
+        <directory>src/main/resources-filtered</directory>
+        <filtering>true</filtering>
+      </resource>
+      <resource>
+        <directory>src/main/resources</directory>
+        <filtering>false</filtering>
+      </resource>
+    </resources>
+  </build>
+
 </project>

jkube-kit/build/service/buildpacks/src/main/java/org/eclipse/jkube/kit/service/buildpacks/BuildPackCliDownloader.java

@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2019 Red Hat, Inc.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at:
+ *
+ *     https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *   Red Hat, Inc. - initial API and implementation
+ */
+package org.eclipse.jkube.kit.service.buildpacks;
+
+import org.apache.commons.lang3.StringUtils;
+import org.eclipse.jkube.kit.common.KitLogger;
+import org.eclipse.jkube.kit.common.util.FileUtil;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Collections;
+import java.util.Properties;
+import java.util.concurrent.atomic.AtomicReference;
+
+import static java.nio.file.StandardCopyOption.COPY_ATTRIBUTES;
+import static java.nio.file.StandardCopyOption.REPLACE_EXISTING;
+import static org.eclipse.jkube.kit.common.util.EnvUtil.findBinaryFileInUserPath;
+import static org.eclipse.jkube.kit.common.util.EnvUtil.getProcessorArchitecture;
+import static org.eclipse.jkube.kit.common.util.EnvUtil.isMacOs;
+import static org.eclipse.jkube.kit.common.util.EnvUtil.isWindows;
+import static org.eclipse.jkube.kit.common.util.EnvUtil.getUserHome;
+import static org.eclipse.jkube.kit.common.util.IoUtil.downloadArchive;
+import static org.eclipse.jkube.kit.common.util.SemanticVersionUtil.removeBuildMetadata;
+
+public class BuildPackCliDownloader {
+  private static final String JKUBE_PACK_DIR = ".jkube";
+  private static final String PACK_UNIX_CLI_NAME = "pack";
+  private static final String PACK_DEFAULT_CLI_VERSION_PROPERTY = "version";
+  private static final String PACK_CLI_LINUX_ARTIFACT = "linux.artifact";
+  private static final String PACK_CLI_LINUX_ARM64_ARTIFACT = "linux-arm64.artifact";
+  private static final String PACK_CLI_MACOS_ARTIFACT = "macos.artifact";
+  private static final String PACK_CLI_MACOS_ARM64_ARTIFACT = "macos-arm64.artifact";
+  private static final String PACK_CLI_WINDOWS_ARTIFACT = "windows.artifact";
+
+  private final KitLogger kitLogger;
+  private final String packCliVersion;
+  private final Properties packProperties;
+  private final File jKubeUserHomeDir;
+
+  public BuildPackCliDownloader(KitLogger kitLogger, Properties packProperties) {
+    this.kitLogger = kitLogger;
+    this.packProperties = packProperties;
+    packCliVersion = (String) packProperties.get(PACK_DEFAULT_CLI_VERSION_PROPERTY);
+    jKubeUserHomeDir = new File(getUserHome(), JKUBE_PACK_DIR);
+  }
+
+  public File getPackCLIIfPresentOrDownload() {
+    try {
+      File pack = resolveBinaryLocation().toFile();
+      if (!(pack.exists() && isValid(pack))) {
+        downloadPackCli();
+      }
+      return pack;
+    } catch (IOException ioException) {
+      kitLogger.warn("Not able to download pack CLI : " + ioException.getMessage());
+      kitLogger.info("Checking for local pack CLI");
+      return getLocalPackCLI();
+    }
+  }
+
+  private void downloadPackCli() throws IOException {
+    File tempDownloadDirectory = FileUtil.createTempDirectory();
+    FileUtil.createDirectory(jKubeUserHomeDir);
+    URL downloadUrl = new URL(inferApplicableDownloadArtifactUrl());
+    Path packInJKubeDir = resolveBinaryLocation();
+    kitLogger.info("Downloading pack CLI %s", packCliVersion);
+
+    downloadArchive(downloadUrl, tempDownloadDirectory);
+
+    File packInExtractedArchive = new File(tempDownloadDirectory, packInJKubeDir.toFile().getName());
+    if (!packInExtractedArchive.exists()) {
+      throw new IllegalStateException("Unable to find " + packInJKubeDir.toFile().getName() + " in downloaded artifact");
+    }
+    if (!packInExtractedArchive.canExecute() && !packInExtractedArchive.setExecutable(true)) {
+      throw new IllegalStateException("Failure in setting execute permission in " + packInExtractedArchive.getAbsolutePath());
+    }
+    Files.copy(packInExtractedArchive.toPath(), packInJKubeDir, REPLACE_EXISTING, COPY_ATTRIBUTES);
+    FileUtil.cleanDirectory(tempDownloadDirectory);
+  }
+
+  private String inferApplicableDownloadArtifactUrl() {
+    boolean isProcessorArchitectureArm = getProcessorArchitecture().equals("aarch64");
+    if (isWindows()) {
+      return (String) packProperties.get(PACK_CLI_WINDOWS_ARTIFACT);
+    } else if (isMacOs() && isProcessorArchitectureArm) {
+      return (String) packProperties.get(PACK_CLI_MACOS_ARM64_ARTIFACT);
+    } else if(isMacOs()) {
+      return (String) packProperties.get(PACK_CLI_MACOS_ARTIFACT);
+    } else if (isProcessorArchitectureArm) {
+      return (String) packProperties.get(PACK_CLI_LINUX_ARM64_ARTIFACT);
+    }
+    return (String) packProperties.get(PACK_CLI_LINUX_ARTIFACT);
+  }
+
+  private File getLocalPackCLI() {
+    File packCliFoundOnUserPath = checkPackCLIPresentOnMachine();
+    if (packCliFoundOnUserPath == null) {
+      throw new IllegalStateException("No local pack binary found");
+    }
+    return packCliFoundOnUserPath;
+  }
+
+  private File checkPackCLIPresentOnMachine() {
+    File packCliFoundOnUserPath = findBinaryFileInUserPath(resolveBinaryLocation().toFile().getName());
+    if (packCliFoundOnUserPath != null && isValid(packCliFoundOnUserPath)) {
+      return packCliFoundOnUserPath;
+    }
+    return null;
+  }
+
+  public boolean isValid(File packCli) {
+    AtomicReference<String> versionRef = new AtomicReference<>();
+    BuildPackCommand versionCommand = new BuildPackCommand(kitLogger, packCli, Collections.singletonList("--version"), versionRef::set);
+    try {
+      versionCommand.execute();
+      String version = removeBuildMetadata(versionRef.get());
+      return StringUtils.isNotBlank(version) && packCliVersion.equals(version);
+    } catch (IOException e) {
+      return false;
+    }
+  }
+
+  private Path resolveBinaryLocation() {
+    String binaryName = PACK_UNIX_CLI_NAME;
+    if (isWindows()) {
+      binaryName = PACK_UNIX_CLI_NAME + "." + packProperties.getProperty("windows.binary-extension");
+    }
+    return jKubeUserHomeDir.toPath().resolve(binaryName);
+  }
+}

jkube-kit/build/service/buildpacks/src/main/java/org/eclipse/jkube/kit/service/buildpacks/BuildPackCommand.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2019 Red Hat, Inc.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at:
+ *
+ *     https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *   Red Hat, Inc. - initial API and implementation
+ */
+package org.eclipse.jkube.kit.service.buildpacks;
+
+import org.eclipse.jkube.kit.common.ExternalCommand;
+import org.eclipse.jkube.kit.common.KitLogger;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Consumer;
+
+public class BuildPackCommand extends ExternalCommand {
+  private final File packCli;
+  private final List<String> commandLineArgs;
+  private final StringBuilder errorBuilder;
+  private final Consumer<String> commandOutputConsumer;
+
+  public BuildPackCommand(KitLogger log, File packCli, List<String> cmdArgs, Consumer<String> outputConsumer) {
+    super(log);
+    this.packCli = packCli;
+    this.commandLineArgs = cmdArgs;
+    this.commandOutputConsumer = outputConsumer;
+    this.errorBuilder = new StringBuilder();
+  }
+
+  @Override
+  public String[] getArgs() {
+    List<String> args = new ArrayList<>();
+    args.add(packCli.getAbsolutePath());
+    args.addAll(commandLineArgs);
+    return args.toArray(new String[0]);
+  }
+
+  @Override
+  public void processLine(String line) {
+    commandOutputConsumer.accept(line);
+  }
+
+  @Override
+  public void processError(String error) {
+    errorBuilder.append(error);
+  }
+
+  public String getError() {
+    return errorBuilder.toString();
+  }
+
+  public int getExitCode() {
+    return getStatusCode();
+  }
+}

jkube-kit/build/service/buildpacks/src/main/resources-filtered/META-INF/jkube/pack-cli.properties

@@ -0,0 +1,21 @@
+#
+# Copyright (c) 2019 Red Hat, Inc.
+# This program and the accompanying materials are made
+# available under the terms of the Eclipse Public License 2.0
+# which is available at:
+#
+#     https://www.eclipse.org/legal/epl-2.0/
+#
+# SPDX-License-Identifier: EPL-2.0
+#
+# Contributors:
+#   Red Hat, Inc. - initial API and implementation
+#
+
+version=${pack.version}
+linux.artifact=${pack.linux.artifact}
+linux-arm64.artifact=${pack.linux-arm64.artifact}
+macos.artifact=${pack.macos.artifact}
+macos-arm64.artifact=${pack.macos-arm64.artifact}
+windows.artifact=${pack.windows.pack.artifact}
+windows.binary-extension=${pack.windows.binary-extension}