KnowledgeManagerImpl: Create temp files in secure sub-folder

src/main/java/com/github/llamara/ai/internal/Utils.java

@@ -29,6 +29,8 @@
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 
+import org.apache.commons.lang3.SystemProperties;
+
 /**
  * Shared utilities and constants.
  *
@@ -99,4 +101,33 @@ public static String buildAzureOpenaiEndpoint(EmbeddingModelConfig config)
                 + ".openai.azure.com/openai/deployments/"
                 + config.model();
     }
+
+    /**
+     * Checks if the host operating system is Unix-like.
+     *
+     * @return <code>true</code> if the host operating system is Unix-like, <code>false</code>
+     *     otherwise
+     */
+    public static boolean isOsUnix() {
+        String osName = SystemProperties.getOsName();
+        return isOsUnix(osName);
+    }
+
+    /**
+     * Check if the given operating system is Unix-like.
+     *
+     * @param osName the name of the operating system
+     * @return <code>true</code> if the operating system is Unix-like, <code>false</code> otherwise
+     */
+    public static boolean isOsUnix(String osName) {
+        osName = osName.toLowerCase();
+        return osName.startsWith("aix")
+                || osName.startsWith("hp-ux")
+                || osName.startsWith("irix")
+                || osName.startsWith("linux")
+                || osName.startsWith("mac")
+                || osName.startsWith("solaris")
+                || osName.startsWith("sunos")
+                || osName.contains("bsd");
+    }
 }

src/main/java/com/github/llamara/ai/internal/knowledge/KnowledgeManagerImpl.java

@@ -22,6 +22,8 @@
 import static com.github.llamara.ai.internal.Utils.generateChecksum;
 
 import com.github.llamara.ai.internal.MetadataKeys;
+import com.github.llamara.ai.internal.StartupException;
+import com.github.llamara.ai.internal.Utils;
 import com.github.llamara.ai.internal.ingestion.DocumentIngestor;
 import com.github.llamara.ai.internal.ingestion.IngestionStatus;
 import com.github.llamara.ai.internal.knowledge.embedding.EmbeddingStorePermissionMetadataManager;
@@ -39,9 +41,13 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
+import java.nio.file.attribute.FileAttribute;
+import java.nio.file.attribute.PosixFilePermission;
+import java.nio.file.attribute.PosixFilePermissions;
 import java.util.Collection;
 import java.util.Map;
 import java.util.Optional;
+import java.util.Set;
 import java.util.UUID;
 import jakarta.enterprise.context.ApplicationScoped;
 import jakarta.inject.Inject;
@@ -76,6 +82,7 @@
 class KnowledgeManagerImpl implements KnowledgeManager {
     private static final String FILE_STORAGE_FILE_NOT_FOUND_PATTERN =
             "File for knowledge '%s' should exist in storage, but is missing";
+    private static final Path TEMP_DIR = Path.of("/tmp/llamara/knowledge");
 
     private final DocumentIngestor ingestor;
     private final EmbeddingStore<TextSegment> embeddingStore;
@@ -97,6 +104,27 @@ class KnowledgeManagerImpl implements KnowledgeManager {
         this.embeddingStorePermissionMetadataManager = embeddingStorePermissionMetadataManager;
     }
 
+    @Startup
+    void init() {
+        try {
+            if (Utils.isOsUnix()) {
+                FileAttribute<Set<PosixFilePermission>> attr =
+                        PosixFilePermissions.asFileAttribute(
+                                PosixFilePermissions.fromString("rwx------"));
+                Files.createDirectories(TEMP_DIR, attr);
+            } else {
+                File f = Files.createDirectories(TEMP_DIR).toFile();
+                if (!f.setReadable(true, true)
+                        || !f.setWritable(true, true)
+                        || !f.setExecutable(true, true)) {
+                    throw new StartupException("Failed to set permissions on temporary directory");
+                }
+            }
+        } catch (IOException e) {
+            throw new StartupException("Failed to create temporary directory", e);
+        }
+    }
+
     @Override
     public Collection<Knowledge> getAllKnowledge() {
         return repository.listAll();
@@ -352,7 +380,7 @@ public void retryFailedIngestion(UUID id)
         NamedFileContainer fc = getFile(id);
         File tempFile;
         try {
-            tempFile = File.createTempFile("knowledge_" + id, null);
+            tempFile = File.createTempFile(id.toString(), null, TEMP_DIR.toFile());
             tempFile.deleteOnExit(); // the file will be deleted when the JVM exits
             Files.copy(fc.content(), tempFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
         } catch (IOException e) {

src/test/java/com/github/llamara/ai/internal/UtilsTest.java

@@ -28,11 +28,15 @@
 
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
 
 /** Tests for {@link Utils}. */
 class UtilsTest {
@@ -112,4 +116,27 @@ void buildAzureOpenAiEndpointThrowsIfResourceNameMissingForEmbeddingModelConfig(
         assertThrows(
                 IllegalArgumentException.class, () -> Utils.buildAzureOpenaiEndpoint(modelConfig));
     }
+
+    @ParameterizedTest
+    @CsvSource({
+        "AIX",
+        "HP-UX",
+        "Irix",
+        "Linux",
+        "Mac OS X",
+        "Solaris",
+        "SunOS",
+        "FreeBSD",
+        "OpenBSD",
+        "NetBSD"
+    })
+    void isOsUnixReturnsTrueIfOnUnix(String osName) {
+        assertTrue(Utils.isOsUnix(osName));
+    }
+
+    @ParameterizedTest
+    @CsvSource({"Windows 10", "Windows 11", "OS/2", "OS/400", "z/OS"})
+    void isOsUnixReturnsFalseIfNotOnUnix(String osName) {
+        assertFalse(Utils.isOsUnix(osName));
+    }
 }