[OSPP]Support Kubernetes ConfigMap for Apollo java, golang client

CHANGES.md

@@ -5,6 +5,8 @@ Release Notes.
 Apollo Java 2.4.0
 
 ------------------
+
+* [Feature Support Kubernetes ConfigMap cache for Apollo java, golang client](https://github.com/apolloconfig/apollo-java/pull/79)
 * [Fix the Cannot enhance @Configuration bean definition issue](https://github.com/apolloconfig/apollo-java/pull/82)
 * [Feature openapi query namespace support not fill item](https://github.com/apolloconfig/apollo-java/pull/83)
 * [Add more observability in apollo config client](https://github.com/apolloconfig/apollo-java/pull/74)

apollo-client/pom.xml

@@ -70,6 +70,10 @@
 			<artifactId>spring-boot-configuration-processor</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>io.kubernetes</groupId>
+			<artifactId>client-java</artifactId>
+		</dependency>
 		<!-- test -->
 		<dependency>
 			<groupId>org.eclipse.jetty</groupId>

apollo-client/src/main/java/com/ctrip/framework/apollo/Kubernetes/KubernetesManager.java

@@ -0,0 +1,180 @@
+/*
+ * Copyright 2022 Apollo Authors
+ *
+ * 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.
+ *
+ */
+package com.ctrip.framework.apollo.Kubernetes;
+
+import io.kubernetes.client.openapi.ApiClient;
+import io.kubernetes.client.openapi.ApiException;
+import io.kubernetes.client.openapi.apis.CoreV1Api;
+import io.kubernetes.client.openapi.Configuration;
+import io.kubernetes.client.openapi.models.*;
+import io.kubernetes.client.util.Config;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+
+import java.util.Map;
+import java.util.Objects;
+import java.util.concurrent.TimeUnit;
+
+@Service
+public class KubernetesManager {
+    private ApiClient client;
+    private CoreV1Api coreV1Api;
+
+    private final Logger log = LoggerFactory.getLogger(this.getClass());
+
+    public KubernetesManager() {
+        try {
+            client = Config.defaultClient();
+            Configuration.setDefaultApiClient(client);
+            coreV1Api = new CoreV1Api(client);
+        } catch (Exception e) {
+            String errorMessage = "Failed to initialize Kubernetes client: " + e.getMessage();
+            log.error(errorMessage, e);
+            throw new RuntimeException(errorMessage, e);
+        }
+    }
+
+    public KubernetesManager(CoreV1Api coreV1Api) {
+        this.coreV1Api = coreV1Api;
+    }
+
+    public V1ConfigMap buildConfigMap(String name, String namespace, Map<String, String> data) {
+        V1ObjectMeta metadata = new V1ObjectMeta()
+                .name(name)
+                .namespace(namespace);
+
+        return new V1ConfigMap()
+                .apiVersion("v1")
+                .kind("ConfigMap")
+                .metadata(metadata)
+                .data(data);
+    }
+
+    /**
+     * Creates a Kubernetes ConfigMap.
+     *
+     * @param configMapNamespace the namespace of the ConfigMap
+     * @param name               the name of the ConfigMap
+     * @param data               the data to be stored in the ConfigMap
+     * @return the name of the created ConfigMap
+     * @throws RuntimeException if an error occurs while creating the ConfigMap
+     */
+    public String createConfigMap(String configMapNamespace, String name, Map<String, String> data) {
+        if (configMapNamespace == null || configMapNamespace.isEmpty() || name == null || name.isEmpty()) {
+            log.error("create configmap failed due to null or empty parameter: configMapNamespace={}, name={}", configMapNamespace, name);
+        }
+        V1ConfigMap configMap = buildConfigMap(name, configMapNamespace, data);
+        try {
+            coreV1Api.createNamespacedConfigMap(configMapNamespace, configMap, null, null, null, null);
+            log.info("ConfigMap created successfully: name: {}, namespace: {}", name, configMapNamespace);
+            return name;
+        } catch (Exception e) {
+            throw new RuntimeException("Failed to create ConfigMap: " + e.getMessage(), e);
+        }
+    }
+
+    /**
+     * get value from config map
+     *
+     * @param configMapNamespace configMapNamespace
+     * @param name               config map name (appId)
+     * @param key                config map key (cluster+namespace)
+     * @return value(json string)
+     */
+    public String getValueFromConfigMap(String configMapNamespace, String name, String key) {
+        if (configMapNamespace == null || configMapNamespace.isEmpty() || name == null || name.isEmpty() || key == null || key.isEmpty()) {
+            log.error("Parameters can not be null or empty: configMapNamespace={}, name={}", configMapNamespace, name);
+            return null;
+        }
+        try {
+            V1ConfigMap configMap = coreV1Api.readNamespacedConfigMap(name, configMapNamespace, null);
+            if (!Objects.requireNonNull(configMap.getData()).containsKey(key)) {
+                throw new RuntimeException(String.format("Specified key not found in ConfigMap: %s, configMapNamespace: %s, name: %s", name, configMapNamespace, name));
+            }
+            return configMap.getData().get(key);
+        } catch (Exception e) {
+            return null;
+        }
+    }
+
+    /**
+     * update config map
+     *
+     * @param configMapNamespace configmap namespace
+     * @param name               config map name (appId)
+     * @param data               new data
+     * @return config map name
+     */
+    // TODO 使用client自带的retry机制，设置重试次数,CAS
+    public boolean updateConfigMap(String configMapNamespace, String name, Map<String, String> data) {
+        if (configMapNamespace == null || configMapNamespace.isEmpty() || name == null || name.isEmpty() || data == null || data.isEmpty()) {
+            log.error("Parameters can not be null or empty: configMapNamespace={}, name={}", configMapNamespace, name);
+            return false;
+        }
+
+        // retry
+        int maxRetries = 5;
+        int retryCount = 0;
+        long waitTime = 100;
+
+        while (retryCount < maxRetries) {
+            try {
+                V1ConfigMap configmap = coreV1Api.readNamespacedConfigMap(name, configMapNamespace, null);
+                configmap.setData(data);
+                coreV1Api.replaceNamespacedConfigMap(name, configMapNamespace, configmap, null, null, null, null);
+                return true;
+            } catch (ApiException e) {
+                if (e.getCode() == 409) {
+                    retryCount++;
+                    log.warn("Conflict occurred, retrying... (" + retryCount + ")");
+                    try {
+                        TimeUnit.MILLISECONDS.sleep(waitTime);
+                    } catch (InterruptedException ie) {
+                        Thread.currentThread().interrupt();
+                    }
+                    waitTime = Math.min(waitTime * 2, 1000);
+                } else {
+                    System.err.println("Error updating ConfigMap: " + e.getMessage());
+                }
+            }
+        }
+        return retryCount < maxRetries;
+    }
+
+    /**
+     * check config map exist
+     *
+     * @param configMapNamespace config map namespace
+     * @param configMapName      config map name
+     * @return true if config map exist, false otherwise
+     */
+    public boolean checkConfigMapExist(String configMapNamespace, String configMapName) {
+        if (configMapNamespace == null || configMapNamespace.isEmpty() || configMapName == null || configMapName.isEmpty()) {
+            log.error("Parameters can not be null or empty: configMapNamespace={}, configMapName={}", configMapNamespace, configMapName);
+            return false;
+        }
+        try {
+            log.info("Check whether ConfigMap exists, configMapName: {}", configMapName);
+            coreV1Api.readNamespacedConfigMap(configMapName, configMapNamespace, null);
+            return true;
+        } catch (Exception e) {
+            // configmap not exist
+            return false;
+        }
+    }
+}

apollo-client/src/main/java/com/ctrip/framework/apollo/enums/ConfigSourceType.java

@@ -22,7 +22,10 @@
  * @since 1.1.0
  */
 public enum ConfigSourceType {
-  REMOTE("Loaded from remote config service"), LOCAL("Loaded from local cache"), NONE("Load failed");
+  REMOTE("Loaded from remote config service"),
+  LOCAL("Loaded from local cache"),
+  CONFIGMAP("Loaded from k8s config map"),
+  NONE("Load failed");
 
   private final String description;