一、环境要求

k8s必须安装metric-server组件

本文使用两种开源包监控方案：1.kubernetes client-java 2.fabric kubernetes-client 使用任意一种即可

二、kubernetes client-java

1.pom配置

 <dependency>
    <groupId>io.kubernetes</groupId>
    <artifactId>client-java</artifactId>
    <version>12.0.0</version>
 </dependency>

官方网址：GitHub - kubernetes-client/java: Official Java client library for kubernetes

2.java代码

ApiClient client = ClientBuilder.kubeconfig(KubeConfig.loadKubeConfig(new FileReader("D:\\test\\kubernetes\\admin.conf"))).build();
                Configuration.setDefaultApiClient(client);  //admin.conf是k8s生成可以拉到本地，或者此处可以使用token连接方式，参见官方demo


                GenericKubernetesApi<NodeMetrics, NodeMetricsList> nodeMetricsListGenericKubernetesApi =  new GenericKubernetesApi<>(
                        NodeMetrics.class,
                        NodeMetricsList.class,
                        "metrics.k8s.io",
                        "v1beta1",
                        "nodes",
                        client);

                NodeMetricsList nodeMetricsList = nodeMetricsListGenericKubernetesApi.list().getObject();
                HashMap<String, Map<String, String>> usages = new HashMap<>();
                for (NodeMetrics item : nodeMetricsList.getItems()) {
                    String name = item.getMetadata().getName();
                    Map<String, Quantity> usage = item.getUsage();
                    Map<String, String> quantity = new HashMap<>();
                    for (String s : usage.keySet()) {
                        Quantity quantity1 = usage.get(s);
                        String s1 = quantity1.toSuffixedString();
                        quantity.put(s,s1);
                    }
                    usages.put(name,quantity);
                }

                CoreV1Api api = new CoreV1Api();

                V1NodeList viNodeList = api.listNode(null, false, null, null, null, 0, null, null, 0, false);
                List<Cllocata> cList = new ArrayList<>();
                for (V1Node v1Node :viNodeList.getItems()){
                    Cllocata cllocata = new Cllocata();
                    V1NodeStatus v1NodeStatus = v1Node.getStatus();
                    List<V1NodeAddress> v1NodeAddresss = v1NodeStatus.getAddresses();
                    for (V1NodeAddress v1NodeAddress:v1NodeAddresss){
                        String type = v1NodeAddress.getType();
                        String address = v1NodeAddress.getAddress();
                        if("InternalIP".equals(type)){
                            cllocata.setIp(address);
                        }else if("Hostname".equals(type)){
                            cllocata.setName(address);
                        }
                    }
                    Map<String, Quantity> map = v1NodeStatus.getAllocatable();
                    cllocata.setCpu(map.get("cpu").toSuffixedString());
                    cllocata.setMemory(map.get("memory").toSuffixedString());
                    cList.add(cllocata);
                }
                Map<String,Object> cMap = new HashMap<>();
                cMap.put("component", ComponentEnum.K8S);
                List<SystemAlarmParams> sapList = systemAlarmParamsMapper.selectByMap(cMap);


                for (Cllocata cllocata :cList){
                    Map<String,String> map = usages.get(cllocata.getName());
                    if(map != null){
                        String cpu = map.get("cpu");
                        cpu = cpu.replace("n","");
                        String memory = map.get("memory");
                        memory = memory.replace("Ki","");

                        String aCpu = cllocata.getCpu();
                        String aMemory = cllocata.getMemory();
                        aMemory = aMemory.replace("Ki","");

                        int pCpu = Math.round(100*Long.parseLong(cpu)/1000/1000/1000/Long.parseLong(aCpu));
                        int pMemory = Math.round(100*Long.parseLong(memory)/Long.parseLong(aMemory));
                        String ip = cllocata.getIp();
                     }
                 }

三、fabric kubernetes-client

1.pom配置

<fabric8.version>5.12.2</fabric8.version>




<dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-client</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-core</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-common</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-rbac</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-admissionregistration</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-apps</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-autoscaling</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-apiextensions</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-batch</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-certificates</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-coordination</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-discovery</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-events</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-extensions</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-flowcontrol</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-networking</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-metrics</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-policy</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-scheduling</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-storageclass</artifactId>
            <version>${fabric8.version}</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-model-node</artifactId>
            <version>${fabric8.version}</version>
        </dependency>

这里使用最新的包，应该从5.0以上官方包内部依赖有问题，所以如上许多子包需要指定版本单独引入，否则默认会引入4.13版本，版本不对应会报许多方法找不到问题 

官方地址：GitHub - fabric8io/kubernetes-client: Java client for Kubernetes & OpenShift

 2.java代码

String adminConfData = IOUtils.toString(new FileInputStream(configPath));
            Config config = Config.fromKubeconfig(adminConfData);
            KubernetesClient client = new DefaultKubernetesClient(config);
NodeMetricsList nodeMetricsList =  client.top().nodes().metrics();
                HashMap<String, Map<String, String>> usages = new HashMap<>();
                for (NodeMetrics item : nodeMetricsList.getItems()) {
                    String name = item.getMetadata().getName();
                    Map<String, Quantity> usage = item.getUsage();
                    Map<String, String> quantity = new HashMap<>();
                    for (String s : usage.keySet()) {
                        Quantity quantity1 = usage.get(s);
                        String s1 = quantity1.toString();
                        quantity.put(s,s1);
                    }
                    usages.put(name,quantity);
                }

                NodeList nodeList = k8sUtil.getNodeList();

                List<Cllocata> cList = new ArrayList<>();
                for (Node node :nodeList.getItems()){
                    Cllocata cllocata = new Cllocata();
                    NodeStatus nodeStatus = node.getStatus();
                    List<NodeAddress> nodeAddresss = nodeStatus.getAddresses();
                    for (NodeAddress nodeAddress:nodeAddresss){
                        String type = nodeAddress.getType();
                        String address = nodeAddress.getAddress();
                        if("InternalIP".equals(type)){
                            cllocata.setIp(address);
                        }else if("Hostname".equals(type)){
                            cllocata.setName(address);
                        }
                    }
                    Map<String, Quantity> map = nodeStatus.getAllocatable();
                    cllocata.setCpu(map.get("cpu").toString());
                    cllocata.setMemory(map.get("memory").toString());
                    cList.add(cllocata);
                }
                Map<String,Object> cMap = new HashMap<>();
                cMap.put("component", ComponentEnum.K8S);
                List<SystemAlarmParams> sapList = systemAlarmParamsMapper.selectByMap(cMap);


                for (Cllocata cllocata :cList){
                    Map<String,String> map = usages.get(cllocata.getName());
                    if(map != null){
                        String cpu = map.get("cpu");
                        Long lCpu = 0L;
                        if(cpu.endsWith("n")){
                            cpu = cpu.replaceAll("n","");
                            lCpu = Long.parseLong(cpu);
                        }else if(cpu.endsWith("m")){
                            cpu = cpu.replaceAll("m","");
                            lCpu = Long.parseLong(cpu)*1000000;
                        }

                        String memory = map.get("memory");
                        Long lMemory = 0L;
                        if(memory.endsWith("Ki")){
                            memory = memory.replaceAll("Ki","");
                            lMemory = Long.parseLong(memory);
                        }else if(memory.endsWith("Mi")){
                            memory = memory.replaceAll("Mi","");
                            lMemory = Long.parseLong(memory)*1024;
                        }

                        String aCpu = cllocata.getCpu();
                        Long laCpu = 0L;
                        if(aCpu.endsWith("n")){
                            aCpu = aCpu.replaceAll("n","");
                            laCpu = Long.parseLong(aCpu);
                        }else if(aCpu.endsWith("m")){
                            aCpu = aCpu.replaceAll("m","");
                            laCpu = Long.parseLong(aCpu)*1000000;
                        }
                        String aMemory = cllocata.getMemory();
                        Long laMemory = 0L;
                        if(aMemory.endsWith("Ki")){
                            aMemory = aMemory.replaceAll("Ki","");
                            laMemory = Long.parseLong(aMemory);
                        }else if(aMemory.endsWith("Mi")){
                            aMemory = aMemory.replaceAll("Mi","");
                            laMemory = Long.parseLong(aMemory)*1024;
                        }

                        int pCpu = Math.round(100*lCpu/laCpu);
                        int pMemory = Math.round(100*lMemory/laMemory);
                        String ip = cllocata.getIp();
          }