**简述：**Elasticsearch是个开源分布式搜索引擎，提供搜集、分析、存储数据三大功能；ELK是三个开源软件的缩写，分别为：Elasticsearch 、 Logstash以及Kibana , 它们都是开源软件。不过现在还新增了一个Beats，它是一个轻量级的日志收集处理工具（Agent），Beats占用资源少，适合于在各个服务器上搜集日志后传输给Logstash，官方也推荐此工具，目前由于原本的ELK Stack成员中加入了 Beats 工具所以已改名为Elastic Stack。而ELK则提供了一整套解决方案，并且都是开源软件，之间互相配合使用，完美衔接，高效的满足了很多场合的应用

ELK官网：https://www.elastic.co/cn/
中文指南：https://www.gitbook.com/book/chenryn/elk-stack-guide-cn/details
安装地址: https://www.elastic.co/cn/start

案例环境：
Centos 7.6 64bit
ip: 192.168.110.66
apps: es,logstash,kibana
k8s集群
master-ip:192.168.110.85
node
…

一. 安装

上官网找到yum源: https://www.elastic.co/guide/en/elasticsearch/reference/7.6/rpm.html#rpm-repo

   yum install elasticsearch -y
   

下载完成之后,修改配置文件:

  vim /etc/elasticsearch/elasticsearch.yml

因为我只在单台节点搭建,就写了一个discovery-host,如果有多个node,添加即可.
调整参数:

vim /etc/security/limits.conf

 vim /etc/sysctl.conf       
 sysctl -p

启服务:

systemctl start elasticsearch

curl '192.168.110.66:9200/_cluster/health?pretty' //测试集群是否健康

安装kibana ,logstash:

  yum -y install kibana logstash

安装完成打开kibana配置文件:


浏览器测试kibana

 cat /etc/logstash/conf.d/logstash.conf

启动logstash

  /usr/share/logstash/bin/logstash --path.settings /etc/logstash/ -f /etc/logstash/conf.d/logstash.conf

 

## **k8smaster**
 cat filebeat.yaml 

```yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: filebeat
  namespace: default
spec:
  selector:
    matchLabels:
        k8s-app: filebeat
  template:
    metadata: 
      labels:
         k8s-app: filebeat
    spec:
      containers:
      - image: elastic/filebeat:7.6.1
        name: filebeat
        args: [
          "-c","/usr/share/filebeat.yml",
          "-e",
        ]
        volumeMounts:
        - name: data
          mountPath: /usr/share/filebeat/data
        - name: filebeat-config
          mountPath: /usr/share/filebeat.yml
        - name: timezone
          mountPath: /etc/localtime
        - name: applogs
          mountPath: /applogs/nginx/
      volumes:
      - name: data
        emptyDir: {}
      - name: filebeat-config
        configMap:
          name: filebeat-config
      - name: timezone
        hostPath:
          path: /etc/localtime
      - name: applogs
        hostPath:
          path: /applogs/nginx/
 ---
apiVersion: v1
kind: ConfigMap
metadata:
  name: filebeat-config
data:
  filebeat.yml: |
    filebeat.inputs:
    - type: log
      paths:
        - /applogs/nginx/*.log
    output.logstash:
      hosts: '192.168.110.66:5044'

以DaemonSet的方式启动filebeat

kubectl apply -f filebeat.yaml

案例:

采集nginx应用日志

 cat nginx.yaml

apiVersion: v1
kind: Service
metadata: 
  name: nginx-svc
spec:
  ports:
    - port: 80
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-pod
spec:
  replicas: 1
  selector: 
    matchLabels:
      app: nginx
  template:
    metadata: 
      labels:
        app: nginx
    spec: 
      containers: 
      - name: nginx-c
        image: yanxiaobing/micro-nginx:v1
        ports: 
        - containerPort: 80
        volumeMounts:
        - name: nginx-log
          mountPath: /var/log/nginx/
        - name: timezone
          mountPath: /etc/localtime
      volumes: 
      - name: nginx-log
        hostPath:
          path: /applogs/nginx/
      - name: timezone
        hostPath: 
          path: /etc/localtime