fix: link launch dir with existing nucleus package if does not exist

src/main/java/com/aws/greengrass/componentmanager/ComponentManager.java

@@ -57,10 +57,12 @@
 import java.security.NoSuchAlgorithmException;
 import java.time.Duration;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ExecutorService;
@@ -71,6 +73,7 @@
 
 import static com.aws.greengrass.componentmanager.KernelConfigResolver.PREV_VERSION_CONFIG_KEY;
 import static com.aws.greengrass.componentmanager.KernelConfigResolver.VERSION_CONFIG_KEY;
+import static com.aws.greengrass.deployment.DeviceConfiguration.DEFAULT_NUCLEUS_COMPONENT_NAME;
 import static com.aws.greengrass.deployment.converter.DeploymentDocumentConverter.ANY_VERSION;
 import static org.apache.commons.io.FileUtils.ONE_MB;
 
@@ -296,6 +299,45 @@ private void storeRecipeDigestInConfigStoreForPlugin(
         }
     }
 
+    /**
+     * Returns a list of local Nucleus artifact paths.
+     *
+     * @return list of local Nucleus paths
+     */
+    public List<Path> findValidLocalNucleusPackage() {
+        List<ComponentIdentifier> localNucleusComponentVersions;
+        try {
+            localNucleusComponentVersions = componentStore.listAvailableComponent(
+                    DEFAULT_NUCLEUS_COMPONENT_NAME, mergeVersionRequirements(Collections.emptyMap()));
+        } catch (PackageLoadingException e) {
+            logger.atDebug().setCause(e).log("Could not list locally available Nucleus versions");
+            return Collections.emptyList();
+        }
+
+        return localNucleusComponentVersions.stream().map(componentIdentifier -> {
+            try {
+                List<File> componentArtifactFiles =
+                        componentStore.getArtifactFileNames(componentIdentifier, artifactDownloaderFactory);
+                return componentArtifactFiles.stream()
+                        .map(file -> {
+                            String artifactFileName = getFileName(file);
+                            try {
+                                return nucleusPaths.unarchiveArtifactPath(componentIdentifier, artifactFileName);
+                            } catch (IOException e) {
+                                logger.atDebug().setCause(e).kv("comp-id", componentIdentifier)
+                                        .kv("file-name", artifactFileName)
+                                        .log("Could not resolve path to unarchived artifact");
+                                return null;
+                            }
+                        }).filter(Objects::nonNull).collect(Collectors.toList());
+            } catch (PackageLoadingException e) {
+                logger.atDebug().setCause(e).kv("version", componentIdentifier)
+                        .log("Could not resolve artifact directory path");
+                return null;
+            }
+        }).filter(Objects::nonNull).flatMap(List::stream).collect(Collectors.toList());
+    }
+
     private Optional<ComponentIdentifier> findBestCandidateLocally(String componentName,
                                                                    Map<String, Requirement> versionRequirements)
             throws PackagingException {

src/main/java/com/aws/greengrass/componentmanager/ComponentStore.java

@@ -47,8 +47,10 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.stream.Collectors;
 import java.util.stream.LongStream;
 import javax.inject.Inject;
 
@@ -412,6 +414,37 @@ public Path resolveArtifactDirectoryPath(@NonNull ComponentIdentifier componentI
         }
     }
 
+    /**
+     * Returns the artifact file name.
+     *
+     * @param componentIdentifier packageIdentifier
+     * @param artifactDownloaderFactory artifact downloader factory
+     * @return the unarchive artifact directory path for target package.
+     * @throws PackageLoadingException if creating the directory fails
+     */
+    public List<File> getArtifactFileNames(@NonNull ComponentIdentifier componentIdentifier,
+                                    @NonNull ArtifactDownloaderFactory artifactDownloaderFactory)
+            throws PackageLoadingException {
+        Optional<String> componentRecipeContent = findComponentRecipeContent(componentIdentifier);
+        if (!componentRecipeContent.isPresent()) {
+            return Collections.emptyList();
+        }
+
+        ComponentRecipe recipe = getPackageRecipe(componentIdentifier);
+        Path packageArtifactDirectory = resolveArtifactDirectoryPath(componentIdentifier);
+        return recipe.getArtifacts().stream().map(artifact -> {
+            try {
+                return artifactDownloaderFactory
+                        .getArtifactDownloader(componentIdentifier, artifact, packageArtifactDirectory)
+                        .getArtifactFile();
+            } catch (PackageLoadingException | InvalidArtifactUriException e) {
+                logger.atDebug().setCause(e).kv("comp-id", componentRecipeContent)
+                        .log("Could not get artifact file");
+                return null;
+            }
+        }).filter(Objects::nonNull).collect(Collectors.toList());
+    }
+
     /**
      * Resolve the recipe file path for a target package id.
      *

src/main/java/com/aws/greengrass/deployment/errorcode/DeploymentErrorCode.java

@@ -64,7 +64,7 @@ public enum DeploymentErrorCode {
     // JVM hashing issue
     HASHING_ALGORITHM_UNAVAILABLE(DeploymentErrorType.DEVICE_ERROR),
     // Could be a local file issue or a Nucleus issue; we will categorize as the latter for visibility
-    LAUNCH_DIRECTORY_CORRUPTED(DeploymentErrorType.NUCLEUS_ERROR),
+    LAUNCH_DIRECTORY_CORRUPTED(DeploymentErrorType.DEVICE_ERROR),
 
     /* Component recipe errors */
     RECIPE_PARSE_ERROR(DeploymentErrorType.COMPONENT_RECIPE_ERROR),

src/main/java/com/aws/greengrass/lifecyclemanager/KernelAlternatives.java

@@ -5,6 +5,8 @@
 
 package com.aws.greengrass.lifecyclemanager;
 
+import com.aws.greengrass.componentmanager.ComponentManager;
+import com.aws.greengrass.componentmanager.exceptions.PackageLoadingException;
 import com.aws.greengrass.config.Configuration;
 import com.aws.greengrass.config.Topics;
 import com.aws.greengrass.dependency.Context;
@@ -35,6 +37,8 @@
 import java.nio.file.Path;
 import java.util.Collections;
 import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 import javax.inject.Inject;
 
@@ -70,15 +74,18 @@ public class KernelAlternatives {
     private static final String BOOTSTRAP_ON_ROLLBACK_CONFIG_KEY = "bootstrapOnRollback";
 
     private final NucleusPaths nucleusPaths;
+    private final ComponentManager componentManager;
 
     /**
      * Constructor for KernelAlternatives, which manages the alternative launch directory of Kernel.
      *
      * @param nucleusPaths nucleus paths
+     * @param componentManager component manager
      */
     @Inject
-    public KernelAlternatives(NucleusPaths nucleusPaths) {
+    public KernelAlternatives(NucleusPaths nucleusPaths, ComponentManager componentManager) {
         this.nucleusPaths = nucleusPaths;
+        this.componentManager = componentManager;
         try {
             setupInitLaunchDirIfAbsent();
         } catch (IOException e) {
@@ -162,31 +169,69 @@ public boolean isLaunchDirSetup() {
         return Files.isSymbolicLink(getCurrentDir()) && validateLaunchDirSetup(getCurrentDir());
     }
 
+    protected boolean canRecoverMissingLaunchDirSetup()
+            throws IOException, URISyntaxException, PackageLoadingException {
+        /*
+        Try and relink launch dir with the following replacement criteria
+        1. check if current Nucleus execution package is valid
+        2. check if any available Nucleus packages in component store is valid
+        3. fail with DirectoryValidationException if above steps do not satisfy
+         */
+        Path currentNucleusExecutablePath = locateCurrentKernelUnpackDir();
+        if (Files.exists(currentNucleusExecutablePath.resolve(KERNEL_BIN_DIR)
+                .resolve(Platform.getInstance().loaderFilename()))) {
+            logger.atDebug().kv("path", currentNucleusExecutablePath)
+                    .log("Current Nucleus executable is valid, setting up launch dir");
+            relinkInitLaunchDir(currentNucleusExecutablePath, true);
+            return true;
+        }
+
+        List<Path> localNucleusExecutablePaths = componentManager.findValidLocalNucleusPackage();
+        if (!localNucleusExecutablePaths.isEmpty()) {
+            Optional<Path> validNucleusExecutablePath = localNucleusExecutablePaths.stream()
+                    .filter(path -> Files.exists(path.resolve(KERNEL_BIN_DIR)
+                            .resolve(Platform.getInstance().loaderFilename())))
+                    .findFirst();
+            if (validNucleusExecutablePath.isPresent()) {
+                logger.atDebug().kv("path", validNucleusExecutablePath.get())
+                        .log("Found a valid Nucleus executable in component store, setting up launch dir");
+                relinkInitLaunchDir(validNucleusExecutablePath.get(), true);
+                return true;
+            }
+        }
+        throw new PackageLoadingException("Could not find a valid Nucleus package to recover launch dir setup");
+    }
+
     /**
      * Validate that launch directory is set up.
      *
      * @throws DirectoryValidationException when a file is missing
      * @throws DeploymentException when user is not allowed to change file permission
      */
     public void validateLaunchDirSetupVerbose() throws DirectoryValidationException, DeploymentException {
-        Path currentDir = getCurrentDir();
-        if (!Files.isSymbolicLink(currentDir)) {
-            throw new DirectoryValidationException("Missing symlink to current nucleus launch directory");
+        try {
+            if (!Files.isSymbolicLink(getCurrentDir()) || !Files.exists(getLoaderPathFromLaunchDir(getCurrentDir()))) {
+                logger.atInfo().log("Current launch dir setup is missing, attempting to recover");
+                canRecoverMissingLaunchDirSetup();
+            }
+        } catch (PackageLoadingException | IOException ex) {
+            throw new DirectoryValidationException("Unable to relink init launch directory", ex);
+        } catch (URISyntaxException ex) {
+            // TODO: Fix usage of root path with spaces on linux
+            throw new DeploymentException("Could not parse init launch directory path", ex);
         }
+
+        Path currentDir = getCurrentDir();
         Path loaderPath = getLoaderPathFromLaunchDir(currentDir);
-        if (Files.exists(loaderPath)) {
-            if (!loaderPath.toFile().canExecute()) {
-                // Ensure that the loader is executable so that we can exec it when restarting Nucleus
-                try {
-                    Platform.getInstance().setPermissions(OWNER_RWX_EVERYONE_RX, loaderPath);
-                } catch (IOException e) {
-                    throw new DeploymentException(
-                            String.format("Unable to set loader script at %s as executable", loaderPath), e)
-                            .withErrorContext(e, DeploymentErrorCode.SET_PERMISSION_ERROR);
-                }
+        if (!loaderPath.toFile().canExecute()) {
+            // Ensure that the loader is executable so that we can exec it when restarting Nucleus
+            try {
+                Platform.getInstance().setPermissions(OWNER_RWX_EVERYONE_RX, loaderPath);
+            } catch (IOException e) {
+                throw new DeploymentException(
+                        String.format("Unable to set loader script at %s as executable", loaderPath), e)
+                        .withErrorContext(e, DeploymentErrorCode.SET_PERMISSION_ERROR);
             }
-        } else {
-            throw new DirectoryValidationException("Missing loader file at " + currentDir.toAbsolutePath());
         }
     }
 

src/main/java/com/aws/greengrass/lifecyclemanager/exceptions/DirectoryValidationException.java

@@ -15,4 +15,9 @@ public DirectoryValidationException(String message) {
         super(message);
         super.addErrorCode(DeploymentErrorCode.LAUNCH_DIRECTORY_CORRUPTED);
     }
+
+    public DirectoryValidationException(String message, Throwable throwable) {
+        super(message, throwable);
+        super.addErrorCode(DeploymentErrorCode.LAUNCH_DIRECTORY_CORRUPTED);
+    }
 }

src/test/java/com/aws/greengrass/deployment/activator/KernelUpdateActivatorTest.java

@@ -227,7 +227,7 @@ void GIVEN_launch_dir_corrupted_WHEN_deployment_activate_THEN_deployment_fail(Ex
         assertEquals(mockException, result.getFailureCause().getCause());
 
         List<String> expectedStack = Arrays.asList("DEPLOYMENT_FAILURE", "LAUNCH_DIRECTORY_CORRUPTED");
-        List<String> expectedTypes = Collections.singletonList("NUCLEUS_ERROR");
+        List<String> expectedTypes = Collections.singletonList("DEVICE_ERROR");
         TestUtils.validateGenerateErrorReport(result.getFailureCause(), expectedStack, expectedTypes);
     }
 

src/test/java/com/aws/greengrass/lifecyclemanager/KernelAlternativesTest.java

@@ -5,9 +5,11 @@
 
 package com.aws.greengrass.lifecyclemanager;
 
+import com.aws.greengrass.componentmanager.ComponentManager;
 import com.aws.greengrass.config.PlatformResolver;
 import com.aws.greengrass.deployment.DeploymentDirectoryManager;
 import com.aws.greengrass.deployment.bootstrap.BootstrapManager;
+import com.aws.greengrass.lifecyclemanager.exceptions.DirectoryValidationException;
 import com.aws.greengrass.testcommons.testutilities.GGExtension;
 import com.aws.greengrass.util.NucleusPaths;
 import com.aws.greengrass.util.Utils;
@@ -34,9 +36,12 @@
 import static org.hamcrest.io.FileMatchers.anExistingFileOrDirectory;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.lenient;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
 import static org.mockito.internal.verification.VerificationModeFactory.times;
@@ -46,8 +51,7 @@ class KernelAlternativesTest {
     @TempDir
     Path altsDir;
     @Mock
-    NucleusPaths nucleusPaths;
-
+    ComponentManager componentManager;
     private KernelAlternatives kernelAlternatives;
     @Mock
     BootstrapManager bootstrapManager;
@@ -58,7 +62,7 @@ class KernelAlternativesTest {
     void beforeEach() throws IOException {
         NucleusPaths paths = new NucleusPaths("mock_loader_logs.log");
         paths.setKernelAltsPath(altsDir);
-        kernelAlternatives = spy(new KernelAlternatives(paths));
+        kernelAlternatives = spy(new KernelAlternatives(paths, componentManager));
     }
 
     @Test
@@ -212,6 +216,38 @@ void GIVEN_launch_params_THEN_write_to_file() throws Exception {
         assertEquals("mock string", new String(Files.readAllBytes(expectedLaunchParamsPath)));
     }
 
+    @Test
+    void GIVEN_validate_launch_dir_setup_WHEN_current_link_missing_and_exception_THEN_directory_validation_exception() throws IOException {
+        // GIVEN
+        Path outsidePath = createRandomDirectory();
+        Path unpackPath = createRandomDirectory();
+        Files.createDirectories(unpackPath.resolve("bin"));
+        String loaderName = "loader";
+        if (PlatformResolver.isWindows) {
+            loaderName = "loader.cmd";
+        }
+        Files.createFile(unpackPath.resolve("bin").resolve(loaderName));
+
+        Path distroPath = kernelAlternatives.getInitDir().resolve(KERNEL_DISTRIBUTION_DIR);
+        Files.createDirectories(kernelAlternatives.getInitDir());
+        // current -> init
+        kernelAlternatives.setupLinkToDirectory(kernelAlternatives.getCurrentDir(), kernelAlternatives.getInitDir());
+        // init/distro -> outsidePath
+        kernelAlternatives.setupLinkToDirectory(distroPath, outsidePath);
+        assertEquals(kernelAlternatives.getInitDir(), Files.readSymbolicLink(kernelAlternatives.getCurrentDir()));
+        assertEquals(outsidePath, Files.readSymbolicLink(distroPath));
+
+        // WHEN
+        Files.deleteIfExists(kernelAlternatives.getCurrentDir());
+        lenient().doThrow(new IOException("Random test failure"))
+                .when(kernelAlternatives).relinkInitLaunchDir(any(Path.class), eq(true));
+
+        // THEN
+        DirectoryValidationException ex =  assertThrows(DirectoryValidationException.class,
+                () -> kernelAlternatives.validateLaunchDirSetupVerbose());
+        assertEquals(ex.getMessage(), "Unable to relink init launch directory");
+    }
+
     private Path createRandomDirectory() throws IOException {
         Path path = altsDir.resolve(Utils.generateRandomString(4));
         Utils.createPaths(path);