Start implementation of registries.conf

pom.xml

@@ -221,6 +221,10 @@
       <groupId>tools.jackson.core</groupId>
       <artifactId>jackson-databind</artifactId>
     </dependency>
+    <dependency>
+      <groupId>tools.jackson.dataformat</groupId>
+      <artifactId>jackson-dataformat-toml</artifactId>
+    </dependency>
 
     <!-- Test dependencies -->
     <dependency>

src/main/java/land/oras/auth/RegistriesConf.java

@@ -0,0 +1,136 @@
+/*-
+ * =LICENSE=
+ * ORAS Java SDK
+ * ===
+ * Copyright (C) 2024 - 2025 ORAS
+ * ===
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =LICENSEEND=
+ */
+
+package land.oras.auth;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Objects;
+import land.oras.exception.OrasException;
+import land.oras.utils.JsonUtils;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Handle registries.conf configuration
+ */
+@NullMarked
+public class RegistriesConf {
+
+    private static final Logger LOG = LoggerFactory.getLogger(RegistriesConf.class);
+
+    /**
+     * The internal config
+     */
+    private final Config config;
+
+    /**
+     * Constructor for RegistriesConf.
+     *
+     * @param config configuration instance.
+     */
+    RegistriesConf(Config config) {
+        this.config = Objects.requireNonNull(config, "Config cannot be null");
+    }
+
+    /**
+     * Create a new RegistriesConf instance by loading configuration from the specified paths.
+     * @param configPaths The list of paths to load configuration from.
+     * @return A new RegistriesConf instance.
+     */
+    public static RegistriesConf newConf(List<Path> configPaths) {
+        List<ConfigFile> files = new ArrayList<>();
+        for (Path configPath : configPaths) {
+            if (Files.exists(configPath)) {
+                ConfigFile configFile = JsonUtils.fromJson(configPath, ConfigFile.class);
+                LOG.debug("Loaded registries config file: {}", configPath);
+                files.add(configFile);
+            }
+        }
+        return new RegistriesConf(Config.load(files));
+    }
+
+    /**
+     * Create a new RegistriesConf instance by loading configuration from standard paths.
+     * @return A new RegistriesConf instance.
+     */
+    public static RegistriesConf newConf() {
+        Path globalPath = Path.of("/etc/containers/registries.conf");
+        List<Path> paths = List.of(
+                globalPath,
+                System.getenv("HOME") != null
+                        ? Path.of(System.getenv("HOME"), ".config", "containers", "registries.conf")
+                        : globalPath);
+        return newConf(paths);
+    }
+
+    /**
+     * The model of the config file
+     *
+     */
+    record ConfigFile(@Nullable List<String> unqualifiedRegistries) {}
+
+    /**
+     * Get the list of unclassified registries.
+     * @return an unmodifiable list of unclassified registries.
+     */
+    public List<String> getUnclassifiedRegistries() {
+        return Collections.unmodifiableList(config.unqualifiedRegistries);
+    }
+
+    /**
+     * Nested Config class for configuration management.
+     */
+    static class Config {
+
+        /**
+         * Private constructor to prevent instantiation.
+         */
+        private Config() {}
+
+        /**
+         * List of unqualified registries.
+         */
+        private final List<String> unqualifiedRegistries = new LinkedList<>();
+
+        /**
+         * Loads the configuration from a JSON file at the specified path and populates registries configuration
+         *
+         * @param configFiles The config files
+         * @return A {@code Config} object populated with config
+         * @throws OrasException If an error occurs while reading or parsing the TOML file.
+         */
+        public static Config load(List<ConfigFile> configFiles) throws OrasException {
+            Config config = new Config();
+            for (ConfigFile configFile : configFiles) {
+                if (configFile.unqualifiedRegistries != null) {
+                    config.unqualifiedRegistries.addAll(configFile.unqualifiedRegistries);
+                }
+            }
+            return config;
+        }
+    }
+}

src/main/java/land/oras/utils/TomlUtils.java

@@ -0,0 +1,101 @@
+/*-
+ * =LICENSE=
+ * ORAS Java SDK
+ * ===
+ * Copyright (C) 2024 - 2025 ORAS
+ * ===
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =LICENSEEND=
+ */
+
+package land.oras.utils;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import land.oras.exception.OrasException;
+import org.jspecify.annotations.NullMarked;
+import tools.jackson.core.JacksonException;
+import tools.jackson.databind.ObjectMapper;
+import tools.jackson.dataformat.toml.TomlMapper;
+
+/**
+ * Utility class for TOML operations.
+ * Use Jackson 3 internally for TOML operations
+ */
+@NullMarked
+public final class TomlUtils {
+
+    /**
+     * TOML mapper instance
+     */
+    private static final ObjectMapper tomlMapper;
+
+    /**
+     * Utils class
+     */
+    private TomlUtils() {
+        // Hide constructor
+    }
+
+    static {
+        tomlMapper = TomlMapper.builder().build();
+    }
+
+    /**
+     * Convert an object to a TOML string
+     * @param object The object to convert
+     * @return The TOML string
+     */
+    public static String toToml(Object object) {
+        try {
+            return tomlMapper.writeValueAsString(object);
+        } catch (JacksonException e) {
+            throw new OrasException("Unable to convert object to TOML string", e);
+        }
+    }
+
+    /**
+     * Convert a TOML string to an object
+     * @param toml The TOML string
+     * @param clazz The class of the object
+     * @param <T> The type of the object
+     * @return The object
+     */
+    public static <T> T fromToml(String toml, Class<T> clazz) {
+        try {
+            return tomlMapper.readValue(toml, clazz);
+        } catch (JacksonException e) {
+            throw new OrasException("Unable to parse TOML string", e);
+        }
+    }
+
+    /**
+     * Convert a TOML string to an object
+     * of the TOML string is not important.
+     * @param path The path to the TOML file
+     * @param clazz The class of the object
+     * @param <T> The type of the object
+     * @return The object
+     */
+    public static <T> T fromToml(Path path, Class<T> clazz) {
+        try {
+            return tomlMapper.readValue(Files.readString(path, StandardCharsets.UTF_8), clazz);
+        } catch (IOException e) {
+            throw new OrasException("Unable to read TOML file due to IO error", e);
+        } catch (JacksonException e) {
+            throw new OrasException("Unable to parse TOML file", e);
+        }
+    }
+}

src/test/java/land/oras/utils/TomlUtilsTest.java

@@ -0,0 +1,63 @@
+/*-
+ * =LICENSE=
+ * ORAS Java SDK
+ * ===
+ * Copyright (C) 2024 - 2025 ORAS
+ * ===
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =LICENSEEND=
+ */
+
+package land.oras.utils;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.nio.file.Path;
+import java.util.Map;
+import land.oras.exception.OrasException;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.CleanupMode;
+import org.junit.jupiter.api.io.TempDir;
+import org.junit.jupiter.api.parallel.Execution;
+import org.junit.jupiter.api.parallel.ExecutionMode;
+
+@Execution(ExecutionMode.CONCURRENT)
+public class TomlUtilsTest {
+
+    /**
+     * Temporary dir
+     */
+    @TempDir(cleanup = CleanupMode.ON_SUCCESS)
+    private static Path dir;
+
+    @Test
+    void failToParseTomlString() {
+        assertThrows(OrasException.class, () -> TomlUtils.fromToml("not a toml", Object.class));
+    }
+
+    @Test
+    @SuppressWarnings("unchecked")
+    void shouldParseToml() {
+        String tomlMap = """
+                key1 = "value1"
+                key2 = "value2"
+                """;
+        Map<String, String> map = TomlUtils.fromToml(tomlMap, Map.class);
+        assertNotNull(map);
+        assertEquals(2, map.size());
+        assertEquals("value1", map.get("key1"));
+        assertEquals("value2", map.get("key2"));
+    }
+}