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
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。
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 |
- 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。
- 部署es集群：
mkdir /elfk & cd /elfk vim elasticsearch.yaml
apiVersion: v1kind: Servicemetadata: name: elasticsearch namespace: default labels: app: elasticsearchspec: selector: app: elasticsearch clusterIP: None ports: - name: api port: 9200 - name: discovery port: 9300---apiVersion: apps/v1kind: StatefulSetmetadata: name: elasticsearch namespace: defaultspec: serviceName: elasticsearch replicas: 3 selector: matchLabels: app: elasticsearch template: metadata: labels: app: elasticsearch spec: containers: - name: elasticsearch image: docker.elastic.co/elasticsearch/elasticsearch-oss:7.6.2 resources: limits: cpu: 1000m requests: cpu: 100m ports: - containerPort: 9200 name: api protocol: TCP - containerPort: 9300 name: discovery protocol: TCP env: - name: "http.host" value: "0.0.0.0" - name: "network.host" value: "_eth0_" - name: "cluster.name" value: "es-cluster" - name: node.name valueFrom: fieldRef: fieldPath: metadata.name - name: "bootstrap.memory_lock" value: "false" - name: "discovery.seed_hosts" value: "elasticsearch" - name: "cluster.initial_master_nodes" value: "elasticsearch-0,elasticsearch-1,elasticsearch-2" - name: "discovery.seed_resolver.timeout" value: "10s" - name: "discovery.zen.minimum_master_nodes" value: "2" - name: "ES_JAVA_OPTS" value: "-Xms512m -Xmx512m" volumeMounts: - name: data mountPath: /usr/share/elasticsearch/data terminationGracePeriodSeconds: 30 volumes: - name: data hostPath: path: /home/elasticsearch/data #该路径为es数据存储目录，自动创建 initContainers: - name: fix-permissions image: busybox command: ["sh", "-c", "chown -R 1000:1000 /usr/share/elasticsearch/data"] securityContext: privileged: true volumeMounts: - name: data mountPath: /usr/share/elasticsearch/data - name: increase-vm-max-map image: busybox command: ["sysctl", "-w", "vm.max_map_count=262144"] securityContext: privileged: true - name: increase-fd-ulimit image: busybox command: ["sh", "-c", "ulimit -n 65536"] securityContext: privileged: true
为了方便，建议提前在所有node节点上拉取elasticsearch镜像：docker pull docker.elastic.co/elasticsearch/elasticsearch-oss:7.6.2。
kubectl apply -f elasticsearch.yaml kubectl get pod NAME READY STATUS RESTARTS AGE elasticsearch-0 1/1 Running 0 110s elasticsearch-1 1/1 Running 0 97s elasticsearch-2 1/1 Running 0 83s kubectl get sts NAME READY AGE elasticsearch 3/3 2m13s
- 部署kibana：
这里为了方便，直接使用NodePort暴露kibana端口。
vim kibana.yaml
apiVersion: v1kind: Servicemetadata: name: kibana namespace: default labels: app: kibanaspec: selector: app: kibana ports: - port: 5601 nodePort: 30080 type: NodePort ---apiVersion: apps/v1kind: Deploymentmetadata: name: kibana namespace: default labels: app: kibanaspec: selector: matchLabels: app: kibana template: metadata: labels: app: kibana spec: containers: - name: kibana image: docker.elastic.co/kibana/kibana-oss:7.6.2 resources: limits: cpu: 1000m requests: cpu: 100m env: - name: ELASTICSEARCH_HOSTS value: "http://elasticsearch:9200" ports: - containerPort: 5601
kubectl apply -f kibana.yaml kubectl get pod |grep kibana kibana-84d7449d95-jg5nt 1/1 Running 0 29s kubectl get deploy |grep kibana kibana 1/1 1 1 53s
部署没问题的话，是可以正常访问kibana页面的，浏览器访问ip:30080，
接下来部署应用程序，收集日志。
- 以sidecar方式部署filebeat收集nginx日志：
vim filebeat-nginx.yaml
apiVersion: v1kind: Servicemetadata:
name: nginx namespace: default labels:
app: nginxspec:
selector:
app: nginx ports:
- port: 80
nodePort: 30090
type: NodePort---apiVersion: v1kind: ConfigMapmetadata:
name: filebeat-config namespace: default labels:
app: filebeatdata:
filebeat.yml: |-
filebeat.config:
inputs:
path: ${path.config}/inputs.d/*.yml reload.enabled: false
modules:
path: ${path.config}/modules.d/*.yml reload.enabled: false
filebeat.inputs:
- type: log paths:
- /logdata/*.log tail_files: true
fields:
pod_name: '${pod_name}'
POD_IP: '${POD_IP}'
setup.template.name: "nginx-logs"
setup.template.pattern: "nginx-logs-*"
output.elasticsearch:
hosts: ["elasticsearch:9200"]
index: "nginx-logs"---apiVersion: apps/v1kind: Deploymentmetadata:
name: nginx namespace: defaultspec:
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-q6xwm 2/2 Running 0 16s kubectl describe pod nginx-865f745bdd-q6xwm Normal Scheduled 51s default-scheduler Successfully assigned default/nginx-865f745bdd-q6xwm to node2 Normal Pulled 50s kubelet, node2 Container image "docker.elastic.co/beats/filebeat-oss:7.6.2" already present on machine Normal Created 50s kubelet, node2 Created container filebeat Normal Started 50s kubelet, node2 Started container filebeat Normal Pulled 50s kubelet, node2 Container image "nginx:1.17.0" already present on machine Normal Created 50s kubelet, node2 Created container nginx Normal Started 50s 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index就是在filebeat配置文件中指定的index——nginx-logs，添加可用的fields：log.file.path后，显示日志来源，
因为上面filebeat配置文件中收集的日志路径是/var/log/nginx/*.log，也可以只指定单个日志（具体的日志路径）并指定index。
- 以sidecar方式部署filebeat收集tomcat日志：
vim filebeat-tomcat.yaml
apiVersion: v1kind: Servicemetadata:
name: tomcat namespace: default labels:
app: tomcatspec:
selector:
app: tomcat ports:
- port: 8080
nodePort: 30100
type: NodePort---apiVersion: v1kind: ConfigMapmetadata:
name: filebeat-config-tomcat namespace: default labels:
app: filebeatdata:
filebeat.yml: |-
filebeat.config:
inputs:
path: ${path.config}/inputs.d/*.yml reload.enabled: false
modules:
path: ${path.config}/modules.d/*.yml reload.enabled: false
filebeat.inputs:
- type: log paths:
- /logdata/*.log tail_files: true
fields:
pod_name: '${pod_name}'
POD_IP: '${POD_IP}'
setup.template.name: "tomcat-logs"
setup.template.pattern: "tomcat-logs-*"
output.elasticsearch:
hosts: ["elasticsearch:9200"]
index: "tomcat-logs"---apiVersion: apps/v1kind: Deploymentmetadata:
name: tomcat namespace: defaultspec:
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-5c7b6644f4-9hslh 2/2 Running 0 16s kubectl describe pod tomcat-5c7b6644f4-9hslh Normal Scheduled 34s default-scheduler Successfully assigned default/tomcat-5c7b6644f4-9hslh to node1 Normal Pulled 33s kubelet, node1 Container image "docker.elastic.co/beats/filebeat-oss:7.6.2" already present on machine Normal Created 33s kubelet, node1 Created container filebeat Normal Started 33s kubelet, node1 Started container filebeat Normal Pulled 33s kubelet, node1 Container image "tomcat:8.0.51-alpine" already present on machine Normal Created 33s kubelet, node1 Created container tomcat Normal Started 33s kubelet, node1 Started container tomcat
访问tomcat页面以产生日志：ip:30100，
- kibana查看tomcat日志：
可以看到index就是在filebeat配置文件中指定的index——tomcat-logs，添加可用的fields：log.file.path后，显示日志来源，
因为上面filebeat配置文件中收集的日志路径是/usr/local/tomcat/logs/*.log，也可以只指定单个日志（具体的日志路径）并指定index。
- 总结：
上面通过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。
上面为了方便，filebeat收集日志是直接输出到es中的，也可以在集群中再部署一个logstash，由filebeat传输到logstash之后进行日志处理再输出到es中，这里就不演示了。
logstash.yaml（参考）：
apiVersion: v1kind: ConfigMapmetadata:
name: logstash-config namespace: defaultdata:
logstash.yml: |
http.host: "0.0.0.0"
path.config: /usr/share/logstash/pipeline
logstash.conf: |
input {
beats {
port => 5044
}
}
filter {
#multiline {
#pattern => "^\d{4}-\d{1,2}-\d{1,2}\s\d{1,2}:\d{1,2}:\d{1,2}"
#negate => true
#what => "previous"
#}
grok {
match => [ "message", "%{TIMESTAMP_ISO8601:logtime} %{LOGLEVEL:level}" ]
}
}
output {
elasticsearch {
hosts => ["elasticsearch:9200"]
index => "your-index-%{+YYYY.MM.dd}" }
}
---kind: ServiceapiVersion: v1metadata:
name: logstash namespace: defaultspec:
selector:
app: logstash ports:
- protocol: TCP port: 5044
targetPort: 5044
type: ClusterIP
---apiVersion: apps/v1kind: Deploymentmetadata:
name: logstash namespace: defaultspec:
selector:
matchLabels:
app: logstash replicas: 1
template:
metadata:
labels:
app: logstash spec:
containers:
- name: logstash image: docker.elastic.co/logstash/logstash-oss:7.6.2 ports:
- containerPort: 5044
volumeMounts:
- name: config mountPath: /usr/share/logstash/config - name: pipeline mountPath: /usr/share/logstash/pipeline volumes:
- name: config configMap:
name: logstash-config items:
- key: logstash.yml path: logstash.yml - name: pipeline configMap:
name: logstash-config items:
- key: logstash.conf path: logstash.conf
kubectl get pod |grep logstash
logstash-6b475db5f6-mxxsj 1/1 Running 0 26s
kubectl logs -f logstash-6b475db5f6-mxxsj[INFO ] 2020-05-17 04:46:22.488 [[main]-pipeline-manager] beats - Beats inputs: Starting input listener {:address=>"0.0.0.0:5044"}[INFO ] 2020-05-17 04:46:22.501 [[main]-pipeline-manager] javapipeline - Pipeline started {"pipeline.id"=>"main"}[INFO ] 2020-05-17 04:46:22.532 [Agent thread] agent - Pipelines running {:count=>1, :running_pipelines=>[:main], :non_running_pipelines=>[]}[INFO ] 2020-05-17 04:46:22.615 [Api Webserver] agent - Successfully started Logstash API endpoint {:port=>9600}[INFO ] 2020-05-17 04:46:22.639 [[main]<beats] Server - Starting server on port: 5044
kubectl get svc |grep logstash
logstash ClusterIP 10.96.103.207 <none> 5044/TCP 1m34s
kubectl get pod |grep nginx nginx-865f745bdd-q6xwm 2/2 Running 0 62m kubectl exec -it nginx-865f745bdd-q6xwm bash[root@nginx-865f745bdd-q6xwm filebeat]# yum install -y telnet[root@nginx-865f745bdd-q6xwm filebeat]# telnet logstash 5044Trying 10.96.103.207... Connected to logstash. Escape character is '^]'.
简单测试部署没问题，filebeat容器测试端口连接也没问题，此处省略进一步配置logstash过滤处理日志的过程。
前面提过，sidecar方式部署filebeat的话，elk组件是否部署在k8s集群内无关紧要，只需要连接没问题即可。上面部署的elk组件是在k8s集群内，接下来将elk部署于k8s集群外测试日志收集。