一.什么是kubesphere

kubesphere是青云推出的kubernetes治理组件,它运行在kubernete集群之上,提供了监控、devops、服务网格等一系列的下层性能。

青云同时还推出了kubekey工具,用以部署kubenetes和kubesphere,反对:

  • 应用kubekey部署kubernetes;
  • 应用kubekey部署kubernetes和kubesphere;

二.部署多master的kubesphere

应用kubekey(即kk)工具部署时,它会先部署kubernetes,而后在此基础上,部署kubesphere。

1.筹备节点

筹备3个Centos7.*节点:

node1  192.168.1.101node2  192.168.1.102node3  192.168.1.103

在每个节点上,装置依赖包:

yum install -y socat conntrack ebtables ipset

2.筹备kubekey

首节点上下载kk:

export KKZONE=cncurl -sfL https://get-kk.kubesphere.io | VERSION=v1.1.1 sh -

3.创立集群配置

应用kk工具,生成集群配置:

./kk create config --with-kubernetes v1.20.6 --with-kubesphere v3.1.1

其中:

  • --with-kubernetes v1.20.6:示意要装置的kubernetes=v1.20.6版本;
  • --with-kubesphere v3.1.1:示意装置的kubesphere=v3.1.1版本,若不愿装置kubespher组件,可不提供该参数;

命名执行结束后,将生成config-sample.yaml文件,批改文件内容:

  • 批改hosts中的节点配置;
  • 多master环境,须要提供controlPlaneEndpoint中的LB地址,这里仅填写其中一个master的ip;
apiVersion: kubekey.kubesphere.io/v1alpha1kind: Clustermetadata:  name: samplespec:  hosts:  - {name: node1, address: 192.168.1.101, internalAddress: 192.168.1.101, user: root, password: ******}  - {name: node2, address: 192.168.1.102, internalAddress: 192.168.1.102, user: root, password: ******}  - {name: node3, address: 192.168.1.103, internalAddress: 192.168.1.103, user: root, password: ******}  roleGroups:    etcd:    - node1    - node2    - node3    master:    - node1    - node2    - node3    worker:    - node1    - node2    - node3  controlPlaneEndpoint:    domain: lb.kubesphere.local    address: "192.168.1.101"    port: 6443  kubernetes:    version: v1.20.6    imageRepo: kubesphere    clusterName: cluster.local  ...

4.创立集群

应用上一步的集群配置,创立集群:

./kk create cluster -f config-sample.yaml

该命令执行过程中,会先创立kubernetes集群,而后再装置kubesphere组件;

装置过程中会打印装置日志,除此之外,还能够通用如下命令查看日志:

kubectl logs -n kubesphere-system $(kubectl get pod -n kubesphere-system -l app=ks-install -o jsonpath='{.items[0].metadata.name}') -f

装置结束后,会输入kubesphere UI的登录信息:

########################################################              Welcome to KubeSphere!           ########################################################Console: http://192.168.1.101:30880Account: ****Password: ****

5.删除集群

若集群装置过程中,呈现谬误,能够删除集群,批改配置后,重新安装:

## 删除集群./kk delete cluster -f config-sample.yaml

三.kubesphere监控组件

装置kubesphere时,会默认装置prometheus的监控组件:

# kubectl get pod -n kubesphere-monitoring-systemNAME                                              READY   STATUS    RESTARTS   AGEalertmanager-main-0                               2/2     Running   0          7d6halertmanager-main-1                               2/2     Running   0          7d6halertmanager-main-2                               2/2     Running   0          7d6hkube-state-metrics-577b8b4cf-7wp5w                3/3     Running   0          7d6hnode-exporter-2p7jz                               2/2     Running   0          7d6hnode-exporter-5njs6                               2/2     Running   0          7d6hnode-exporter-6ndb9                               2/2     Running   0          7d6hnotification-manager-deployment-97dfccc89-625b8   1/1     Running   0          7d6hnotification-manager-deployment-97dfccc89-k8767   1/1     Running   0          7d6hnotification-manager-operator-59cbfc566b-4wp9m    2/2     Running   4          7d6hprometheus-k8s-0                                  3/3     Running   1          4d4hprometheus-k8s-1                                  3/3     Running   1          4d4hprometheus-operator-8f97cb8c6-dq4d2               2/2     Running   0          7d6h

kubesphere的监控组件,应用prometheus-operator来治理prometheus的各种prometheusrule、serviceMonitor等各种CRD对象及其状态变动。

具体部署的prometheus、alertmanager的正本数,在ks-installer中指定:

prometheus的正本数:

  • 若节点数<3,则默认prometheus正本数=1;
  • 若节点数>=3,则默认prometheus正本数=2;
// ks-installer/roles/ks-monitor/template/prometheus-prometheus.yaml.j2{% if nodeNum is defined and nodeNum < 3 %}  replicas: {{ monitoring.prometheus.replicas | default(monitoring.prometheusReplicas) | default(1) }}{% else %}  replicas: {{ monitoring.prometheus.replicas | default(monitoring.prometheusReplicas) | default(2) }}{% endif %}

alertmanager的正本数:

  • 若节点数<3,则默认alertmanager正本数=1;
  • 若节点数>=3,则默认alertmanager正本数=3;
// ks-installer/roles/ks-monitor/template/alertmanager-alertmanager.yaml.j2{% if nodeNum is defined and nodeNum < 3 %}  replicas: {{ monitoring.alertmanager.replicas | default(monitoring.alertmanagerReplicas) | default(1) }}{% else %}  replicas: {{ monitoring.alertmanager.replicas | default(monitoring.alertmanagerReplicas) | default(3) }}{% endif %}

四.kubesphere监控API源码

以kubesphere上监控集群CPU应用状况为例,剖析其前后端监控的API接口,及其源码实现:

1.前端调用:

GET http://192.168.1.101:30880/kapis/monitoring.kubesphere.io/v1alpha3/cluster?start=1653737380&end=1653743380&step=120s&times=50&metrics_filter=cluster_cpu_utilisation

能够看到,指标名称为cluster_cpu_utilisation。

2.后端代码:

API 注册的代码:

// kubesphere/pkg/kapis/monitoring/v1alpha3/register.gofunc AddToContainer(c *restful.Container, ...) error {...        ws.Route(ws.GET("/cluster").            To(h.handleClusterMetricsQuery).            Doc("Get cluster-level metric data.").            Param(ws.QueryParameter("metrics_filter", "The metric name filter consists of a regexp pattern. It specifies which metric data to return. For example, the following filter matches both cluster CPU usage and disk usage: `cluster_cpu_usage|cluster_disk_size_usage`. View available metrics at [kubesphere.io](https://docs.kubesphere.io/advanced-v2.0/zh-CN/api-reference/monitoring-metrics/).").DataType("string").Required(false)).            Param(ws.QueryParameter("start", "Start time of query. Use **start** and **end** to retrieve metric data over a time span. It is a string with Unix time format, eg. 1559347200. ").DataType("string").Required(false)).            Param(ws.QueryParameter("end", "End time of query. Use **start** and **end** to retrieve metric data over a time span. It is a string with Unix time format, eg. 1561939200. ").DataType("string").Required(false)).            Param(ws.QueryParameter("step", "Time interval. Retrieve metric data at a fixed interval within the time range of start and end. It requires both **start** and **end** are provided. The format is [0-9]+[smhdwy]. Defaults to 10m (i.e. 10 min).").DataType("string").DefaultValue("10m").Required(false)).            Param(ws.QueryParameter("time", "A timestamp in Unix time format. Retrieve metric data at a single point in time. Defaults to now. Time and the combination of start, end, step are mutually exclusive.").DataType("string").Required(false)).            Metadata(restfulspec.KeyOpenAPITags, []string{constants.ClusterMetricsTag}).            Writes(model.Metrics{}).            Returns(http.StatusOK, respOK, model.Metrics{})).            Produces(restful.MIME_JSON)...}

API handler的代码:

// kubesphere/pkg/kapis/monitoring/v1alpha3/handler.gofunc (h handler) handleClusterMetricsQuery(req *restful.Request, resp *restful.Response) {    params := parseRequestParams(req)    opt, err := h.makeQueryOptions(params, monitoring.LevelCluster)    if err != nil {        api.HandleBadRequest(resp, nil, err)        return    }    h.handleNamedMetricsQuery(resp, opt)}

具体查问时,它会向prometheus发送metric的查问:

  • 查问表达式:makeExpr(metric, *ops),这里metric=cluster_cpu_utilisation;
  • 执行查问:p.client.QueryRange(...),向prometheus发动查问;
// kubesphere/pkg/simple/client/monitoring/prometheus/prometheus.gofunc (p prometheus) GetNamedMetricsOverTime(metrics []string, start, end time.Time, step time.Duration, o monitoring.QueryOption) []monitoring.Metric {  var res []monitoring.Metric  ...    timeRange := apiv1.Range{        Start: start,        End:   end,        Step:  step,    }    for _, metric := range metrics {        wg.Add(1)        go func(metric string) {            parsedResp := monitoring.Metric{MetricName: metric}            //查问prometheus            value, _, err := p.client.QueryRange(context.Background(), makeExpr(metric, *opts), timeRange)             parsedResp.MetricData = parseQueryRangeResp(value, genMetricFilter(o))            ...            res = append(res, parsedResp)            wg.Done()        }(metric)    }    wg.Wait()    return res}

重点看一下如何结构查问表达式:

// kubesphere/pkg/simple/client/monitoring/prometheus/promql.govar promQLTemplates = map[string]string{    //cluster    "cluster_cpu_utilisation":            ":node_cpu_utilisation:avg1m",    ...}func makeExpr(metric string, opts monitoring.QueryOptions) string {    tmpl := promQLTemplates[metric]    switch opts.Level {    case monitoring.LevelCluster:        return tmpl    ...}

对于前端查问的cluster_cpu_utilisation,发给prometheus的是":node_cpu_utilisation:avg1m",prometheus上这样一条表达式规定:

- expr: |    avg(irate(node_cpu_used_seconds_total{job="node-exporter"}[5m]))  record: :node_cpu_utilisation:avg1m

所以,cluster_cpu_utilisation指标最终是执行如下promql的查问后果:

avg(irate(node_cpu_used_seconds_total{job="node-exporter"}[5m]))

参考:

1.https://v3-1.docs.kubesphere....
2.https://kubesphere.com.cn/for...