elfk收集k8s日志（三）

本文介绍通过elk + filebeat方式收集k8s日志，其中filebeat以sidecar方式部署。elfk最新版本：7.6.2

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k8s日志收集方案

• 3种日志收集方案：

1. node上部署一个日志收集程序

    Daemonset方式部署日志收集程序，对本节点 /var/log 和 /var/lib/docker/containers 两个目录下的日志进行采集
    
2. sidecar方式部署日志收集程序

    每个运行应用程序的pod中附加一个日志收集的容器，使用 emptyDir 共享日志目录让日志容器收集日志
    
3. 应用程序直接推送日志

    常见的如 graylog 工具，直接修改代码推送日志到es，然后在graylog上展示出来

• 3种收集方案的优缺点：

方案	优点	缺点
1. node上部署一个日志收集程序	每个node仅需部署一个日志收集程序，消耗资源少，对应用无侵入	应用程序日志需要写到标准输出和标准错误输出，不支持多行日志
2. pod中附加一个日志收集容器	低耦合	每个pod启动一个日志收集容器，增加资源消耗
3. 应用程序直接推送日志	无需额外收集工具	侵入应用，增加应用复杂度

下面测试第1种方案：每个node上部署一个日志收集程序，注意elfk版本保持一致。

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SideCar方式收集k8s日志

• 主机说明：

系统	ip	角色	cpu	内存	hostname
CentOS 7.8	192.168.30.128	master、deploy	>=2	>=2G	master1
CentOS 7.8	192.168.30.129	master	>=2	>=2G	master2
CentOS 7.8	192.168.30.130	node	>=2	>=2G	node1
CentOS 7.8	192.168.30.131	node	>=2	>=2G	node2
CentOS 7.8	192.168.30.132	node	>=2	>=2G	node3
CentOS 7.8	192.168.30.133	test	>=2	>=2G	test

• 搭建k8s集群：

搭建过程省略，具体参考：Kubeadm方式搭建k8s集群 或 二进制方式搭建k8s集群

搭建完成后，查看集群：

kubectl get nodes

NAME      STATUS   ROLES    AGE     VERSION
master1   Ready    master   4d16h   v1.14.0
master2   Ready    master   4d16h   v1.14.0
node1     Ready    <none>   4d16h   v1.14.0
node2     Ready    <none>   4d16h   v1.14.0
node3     Ready    <none>   4d16h   v1.14.0

这里为了方便，直接使用之前的k8s集群，注意删除之前实验的k8s资源对象。

• docker-compose部署elk：

部署过程参考：docker-compose部署elfk

mkdir /software & cd /software

git clone https://github.com/Tobewont/elfk-docker.git

cd elfk-docker/

echo 'ELK_VERSION=7.6.2' > .env             #替换版本

vim elasticsearch/Dockerfile

ARG ELK_VERSION=7.6.2

# https://github.com/elastic/elasticsearch-docker
FROM docker.elastic.co/elasticsearch/elasticsearch-oss:${ELK_VERSION}
# FROM elasticsearch:${ELK_VERSION}
# Add your elasticsearch plugins setup here
# Example: RUN elasticsearch-plugin install analysis-icu

vim elasticsearch/config/elasticsearch.yml 

---
## Default Elasticsearch configuration from Elasticsearch base image.
## https://github.com/elastic/elasticsearch/blob/master/distribution/docker/src/docker/config/elasticsearch.yml
#
cluster.name: "docker-cluster"
network.host: "0.0.0.0"

## X-Pack settings
## see https://www.elastic.co/guide/en/elasticsearch/reference/current/setup-xpack.html
#
#xpack.license.self_generated.type: trial        #trial为试用版，一个月期限，可更改为basic版本
#xpack.security.enabled: true
#xpack.monitoring.collection.enabled: true

#http.cors.enabled: true
#http.cors.allow-origin: "*"
#http.cors.allow-headers: Authorization,X-Requested-With,Content-Length,Content-Type

vim kibana/Dockerfile 

ARG ELK_VERSION=7.6.2

# https://github.com/elastic/kibana-docker
FROM docker.elastic.co/kibana/kibana-oss:${ELK_VERSION}
# FROM kibana:${ELK_VERSION}

# Add your kibana plugins setup here
# Example: RUN kibana-plugin install 

vim kibana/config/kibana.yml 

---
## Default Kibana configuration from Kibana base image.
## https://github.com/elastic/kibana/blob/master/src/dev/build/tasks/os_packages/docker_generator/templates/kibana_yml.template.js
#
server.name: "kibana"
server.host: "0.0.0.0"
elasticsearch.hosts: [ "http://elasticsearch:9200" ]
# xpack.monitoring.ui.container.elasticsearch.enabled: true

## X-Pack security credentials
#
# elasticsearch.username: elastic
# elasticsearch.password: changeme

vim logstash/Dockerfile

ARG ELK_VERSION=7.6.2

# https://github.com/elastic/logstash-docker
FROM docker.elastic.co/logstash/logstash-oss:${ELK_VERSION}
# FROM logstash:${ELK_VERSION}

# Add your logstash plugins setup here
# Example: RUN logstash-plugin install logstash-filter-json

RUN logstash-plugin install logstash-filter-multiline

vim logstash/config/logstash.yml 

---
## Default Logstash configuration from Logstash base image.
## https://github.com/elastic/logstash/blob/master/docker/data/logstash/config/logstash-full.yml
#
http.host: "0.0.0.0"
#xpack.monitoring.elasticsearch.hosts: [ "http://elasticsearch:9200" ]

## X-Pack security credentials
#
#xpack.monitoring.enabled: true
#xpack.monitoring.elasticsearch.username: elastic
#xpack.monitoring.elasticsearch.password: changeme
#xpack.monitoring.collection.interval: 10s

vim logstash/pipeline/logstash.conf             #如果filebeat配置文件中没有配置多行合并，可以在logstash中进行多行合并

input {
    beats {
        port => 5040
    }
}

filter {
    if [type] == "nginx_access" {
        #multiline {
            #pattern => "^\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}"
            #negate => true
            #what => "previous"
        #}

        grok {
            match => [ "message", "%{IPV4:remote_addr} - (%{USERNAME:user}|-) \[%{HTTPDATE:log_timestamp}\] \"%{WORD:method} %{DATA:request} HTTP/%{NUMBER:httpversion}\" %{NUMBER:status} %{NUMBER:bytes} %{QS:referer} %{QS:agent} %{QS:xforward}" ]
        }
    }
    
    if [type] == "nginx_error" {
        #multiline {
            #pattern => "^\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}"
            #negate => true
            #what => "previous"
        #}

        grok {
            match => [ "message", "%{IPV4:remote_addr} - (%{USERNAME:user}|-) \[%{HTTPDATE:log_timestamp}\] \"%{WORD:method} %{DATA:request} HTTP/%{NUMBER:httpversion}\" %{NUMBER:status} %{NUMBER:bytes} %{QS:referer} %{QS:agent} %{QS:xforward}" ]
        }
    }
    
    if [type] == "tomcat_catalina" {
        #multiline {
            #pattern => "^\d{1,2}-\S{3}-\d{4}\s\d{1,2}:\d{1,2}:\d{1,2}"
            #negate => true
            #what => "previous"
        #}

        grok {
            match => [ "message", "(?%{MONTHDAY}-%{MONTH}-%{YEAR} %{TIME}) %{LOGLEVEL:severity} \[%{DATA:exception_info}\] %{GREEDYDATA:message}" ]
        }
    }
}

output {
    if [type] == "nginx_access" {
        elasticsearch {
            hosts => ["elasticsearch:9200"]
            #user => "elastic"
            #password => "changeme"
            index => "nginx-access"
        }
    }
    
    if [type] == "nginx_error" {
        elasticsearch {
            hosts => ["elasticsearch:9200"]
            #user => "elastic"
            #password => "changeme"
            index => "nginx-error"
        }
    }
    
    if [type] == "tomcat_catalina" {
        elasticsearch {
            hosts => ["elasticsearch:9200"]
            #user => "elastic"
            #password => "changeme"
            index => "tomcat-catalina"
        }
    }
}

vim docker-compose.yml

version: '3.7'

services:
  elasticsearch:
    build:
      context: elasticsearch/
      args:
        ELK_VERSION: $ELK_VERSION
    volumes:
      - type: bind
        source: ./elasticsearch/config/elasticsearch.yml
        target: /usr/share/elasticsearch/config/elasticsearch.yml
        read_only: true
      - type: volume
        source: elasticsearch
        target: /usr/share/elasticsearch/data
    ports:
      - "9200:9200"
      - "9300:9300"
    environment:
      ES_JAVA_OPTS: "-Xmx256m -Xms256m"
      ELASTIC_PASSWORD: changeme
      discovery.type: single-node
    networks:
      - elk

  logstash:
    depends_on:
      - elasticsearch
    build:
      context: logstash/
      args:
        ELK_VERSION: $ELK_VERSION
    volumes:
      - type: bind
        source: ./logstash/config/logstash.yml
        target: /usr/share/logstash/config/logstash.yml
        read_only: true
      - type: bind
        source: ./logstash/pipeline
        target: /usr/share/logstash/pipeline
        read_only: true
    ports:
      - "5040:5040"
      - "9600:9600"
    environment:
      LS_JAVA_OPTS: "-Xmx256m -Xms256m"
    networks:
      - elk

  kibana:
    depends_on:
      - elasticsearch
    build:
      context: kibana/
      args:
        ELK_VERSION: $ELK_VERSION
    volumes:
      - type: bind
        source: ./kibana/config/kibana.yml
        target: /usr/share/kibana/config/kibana.yml
        read_only: true
    ports:
      - "5601:5601"
    networks:
      - elk

volumes:
  elasticsearch:
#    driver: local
#    driver_opts:
#      type: none
#      o: bind
#      device: /home/elfk/elasticsearch/data

networks:
  elk:
    driver: bridge

为了方便，建议提前在test节点上拉取需要的镜像：

docker pull docker.elastic.co/elasticsearch/elasticsearch-oss:7.6.2

docker pull docker.elastic.co/kibana/kibana-oss:7.6.2

docker pull docker.elastic.co/logstash/logstash-oss:7.6.2

docker-compose up --build -d

docker-compose ps

           Name                          Command               State                            Ports                          
-------------------------------------------------------------------------------------------------------------------------------
elfk-docker_elasticsearch_1   /usr/local/bin/docker-entr ...   Up      0.0.0.0:9200->9200/tcp, 0.0.0.0:9300->9300/tcp          
elfk-docker_kibana_1          /usr/local/bin/dumb-init - ...   Up      0.0.0.0:5601->5601/tcp                                  
elfk-docker_logstash_1        /usr/local/bin/docker-entr ...   Up      0.0.0.0:5040->5040/tcp, 5044/tcp, 0.0.0.0:9600->9600/tcp

访问kibana页面：ip:5601，

elk容器启动正常，kibana访问正常。接下来sidecar方式部署filebeat收集应用日志。

• 以sidecar方式部署filebeat收集nginx日志：

vim filebeat-nginx.yaml

apiVersion: v1
kind: Service
metadata:
  name: nginx
  namespace: default
  labels:
    app: nginx
spec:
  selector:
    app: nginx
  ports:
  - port: 80
    nodePort: 30090
  type: NodePort

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: filebeat-config
  namespace: default
  labels:
    app: filebeat
data:
  filebeat.yml: |-
    filebeat.config:
      inputs:
        path: ${path.config}/inputs.d/*.yml
        reload.enabled: false

      modules:
        path: ${path.config}/modules.d/*.yml
        reload.enabled: false
    filebeat.inputs:
    - type: log
      paths:
        - /logdata/access.log
      tail_files: true
      fields:
        pod_name: '${pod_name}'
        POD_IP: '${POD_IP}'
        type: nginx_access
      fields_under_root: true
      multiline.pattern: '^\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}'
      multiline.negate: true
      multiline.match: after
    - type: log
      paths:
        - /logdata/error.log
      tail_files: true
      fields:
        pod_name: '${pod_name}'
        POD_IP: '${POD_IP}'
        type: nginx_error
      fields_under_root: true
      multiline.pattern: '^\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}'
      multiline.negate: true
      multiline.match: after

    output.logstash:
      hosts: ["192.168.30.133:5040"]
      enabled: true
      worker: 1
      compression_level: 3

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  namespace: default
spec:
  replicas: 1
  minReadySeconds: 15
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      terminationGracePeriodSeconds: 30
      containers:
      - name: filebeat
        image: docker.elastic.co/beats/filebeat-oss:7.6.2
        args: [
          "-c", "/etc/filebeat/filebeat.yml",
          "-e",
        ]
        env:
        - name: POD_IP
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: status.podIP
        - name: pod_name
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: metadata.name
        securityContext:
          runAsUser: 0
        resources:
          limits:
            memory: 200Mi
          requests:
            cpu: 200m
            memory: 200Mi
        volumeMounts:
        - name: config
          mountPath: /etc/filebeat/
        - name: data
          mountPath: /usr/share/filebeat/data
        - name: logdata
          mountPath: /logdata
      - name: nginx
        image: nginx:1.17.0
        ports:
        - containerPort: 80
        volumeMounts:
        - name: logdata
          mountPath: /var/log/nginx
      volumes:
      - name: data
        emptyDir: {}
      - name: logdata
        emptyDir: {}
      - name: config
        configMap:
          name: filebeat-config
          items:
          - key: filebeat.yml
            path: filebeat.yml

kubectl apply -f filebeat-nginx.yaml

kubectl get pod |grep nginx

nginx-865f745bdd-mkdl6   2/2     Running   0          15s

kubectl describe pod nginx-865f745bdd-mkdl6

  Normal  Scheduled  36s   default-scheduler  Successfully assigned default/nginx-865f745bdd-mkdl6 to node2
  Normal  Pulled     34s   kubelet, node2     Container image "docker.elastic.co/beats/filebeat-oss:7.6.2" already present on machine
  Normal  Created    34s   kubelet, node2     Created container filebeat
  Normal  Started    34s   kubelet, node2     Started container filebeat
  Normal  Pulled     34s   kubelet, node2     Container image "nginx:1.17.0" already present on machine
  Normal  Created    34s   kubelet, node2     Created container nginx
  Normal  Started    34s   kubelet, node2     Started container nginx

访问nginx页面以产生日志：ip:30090，

• kibana创建索引，查看nginx日志：

可以看到，已经有指定的index——nginx-access产生，创建同名索引查看日志，

nginx的访问日志通过logstash处理之后已产生对应的字段。访问不存在的url（如ip:30090/index.php）以产生错误的nginx日志，

到kibana页面查看是否有index产生，

可以看到，已经有指定的index——nginx-error产生，创建同名索引查看日志，

查看对应的nginx访问日志，

nginx日志收集完成。

• 以sidecar方式部署filebeat收集tomcat日志：

vim filebeat-tomcat.yaml

apiVersion: v1
kind: Service
metadata:
  name: tomcat
  namespace: default
  labels:
    app: tomcat
spec:
  selector:
    app: tomcat
  ports:
  - port: 8080
    nodePort: 30100
  type: NodePort

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: filebeat-config-tomcat
  namespace: default
  labels:
    app: filebeat
data:
  filebeat.yml: |-
    filebeat.config:
      inputs:
        path: ${path.config}/inputs.d/*.yml
        reload.enabled: false

      modules:
        path: ${path.config}/modules.d/*.yml
        reload.enabled: false
    filebeat.inputs:
    - type: log
      paths:
        - /logdata/catalina*.log
      tail_files: true
      fields:
        pod_name: '${pod_name}'
        POD_IP: '${POD_IP}'
        type: tomcat_catalina
      fields_under_root: true
      multiline.pattern: '^\d{1,2}-\S{3}-\d{4}\s\d{1,2}:\d{1,2}:\d{1,2}'
      multiline.negate: true
      multiline.match: after

    output.logstash:
      hosts: ["192.168.30.133:5040"]
      enabled: true
      worker: 1
      compression_level: 3

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: tomcat
  namespace: default
spec:
  replicas: 1
  minReadySeconds: 15
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
  selector:
    matchLabels:
      app: tomcat
  template:
    metadata:
      labels:
        app: tomcat
    spec:
      terminationGracePeriodSeconds: 30
      containers:
      - name: filebeat
        image: docker.elastic.co/beats/filebeat-oss:7.6.2
        args: [
          "-c", "/etc/filebeat/filebeat.yml",
          "-e",
        ]
        env:
        - name: POD_IP
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: status.podIP
        - name: pod_name
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: metadata.name
        securityContext:
          runAsUser: 0
        resources:
          limits:
            memory: 200Mi
          requests:
            cpu: 200m
            memory: 200Mi
        volumeMounts:
        - name: config
          mountPath: /etc/filebeat/
        - name: data
          mountPath: /usr/share/filebeat/data
        - name: logdata
          mountPath: /logdata
      - name: tomcat
        image: tomcat:8.0.51-alpine
        ports:
        - containerPort: 8080
        volumeMounts:
        - name: logdata
          mountPath: /usr/local/tomcat/logs
      volumes:
      - name: data
        emptyDir: {}
      - name: logdata
        emptyDir: {}
      - name: config
        configMap:
          name: filebeat-config-tomcat
          items:
          - key: filebeat.yml
            path: filebeat.yml

kubectl apply -f filebeat-tomcat.yaml

kubectl get pod |grep tomcat

tomcat-5c7b6644f4-jwmxc   2/2     Running   0          10s

kubectl describe pod tomcat-5c7b6644f4-jwmxc

  Normal  Scheduled  35s   default-scheduler  Successfully assigned default/tomcat-5c7b6644f4-jwmxc to node1
  Normal  Pulled     34s   kubelet, node1     Container image "docker.elastic.co/beats/filebeat-oss:7.6.2" already present on machine
  Normal  Created    34s   kubelet, node1     Created container filebeat
  Normal  Started    34s   kubelet, node1     Started container filebeat
  Normal  Pulled     34s   kubelet, node1     Container image "tomcat:8.0.51-alpine" already present on machine
  Normal  Created    34s   kubelet, node1     Created container tomcat
  Normal  Started    34s   kubelet, node1     Started container tomcat

访问tomcat页面以产生日志：ip:30100，

• kibana创建索引，查看tomcat日志：

可以看到，已经有指定的index——tomcat-catalina产生，创建同名索引查看日志，

tomcat的catalina日志通过logstash处理之后已产生对应的字段。tomcat日志收集完成。

• 总结：

通过sidecar方式部署filebeat收集k8s日志，比使用logagent方式部署filebeat收集k8s日志更加直接，可以指定具体路径并自定义index，在查看日志时也更加方便，缺点就是会增加资源消耗，不过资源消耗在可接受的范围内。

需要注意的是，filebeat对不同应用程序日志收集的ConfigMap名称尽量不要相同，避免冲突和误删除。

在前面，filebeat收集日志是直接输出到es中的，而且elk是部署在k8s集群中的。本文中filebeat收集日志是传输到logstash之后进行日志处理再输出到es中的，而且elk单独部署（这里为了方便，采用docker-compose部署，也可以传统方式部署）。

至此，elk + filebeat收集k8s日志完毕。个人感觉sidecar方式比logagent方式更为合适，在日志的过滤处理和查看方面更为简单有效。另外对于错误日志的告警，参考 ELK集群部署（三），此处不再赘述。

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