参考文档

https://yq.aliyun.com/articles/679721
https://www.cnblogs.com/keithtt/p/6410249.html
https://github.com/kiwigrid/helm-charts/tree/master/charts/fluentd-elasticsearch
https://github.com/kubernetes/kubernetes/tree/5d9d5bca796774a2c12d4e4443e684b619cda7ee/cluster/addons/fluentd-elasticsearch

Kubernetes日志收集汇总

关于kubernetes的日志分好几种，针对kubernetes本身而言有三种：
1、资源运行时的event事件。比如在k8s集群中创建pod之后，可以通过 kubectl describe pod 命令查看pod的详细信息。
2、容器中运行的应用程序自身产生的日志，比如tomcat、nginx、php的运行日志。比如kubectl logs redis-master-bobr0。这也是官方以及网上多数文章介绍的部分。
3、k8s各组件的服务日志，比如 systemctl status kubelet。

容器日志收集的方式通常有以下几种：
1、容器外收集。将宿主机的目录挂载为容器的日志目录，然后在宿主机上收集。
2、容器内收集。在容器内运行一个后台日志收集服务。
3、单独运行日志容器。单独运行一个容器提供共享日志卷，在日志容器中收集日志。
4、网络收集。容器内应用将日志直接发送到日志中心，比如java程序可以使用log4j 2转换日志格式并发送到远端。
5、通过修改docker的--log-driver。可以利用不同的driver把日志输出到不同地方，将log-driver设置为syslog、fluentd、splunk等日志收集服务，然后发送到远端。

Fluentd-Elasticsearch功能简介

Fluentd is deployed as a DaemonSet which spawns a pod on each node that reads logs, generated by kubelet, container runtime and containers and sends them to Elasticsearch.
Fluentd被部署为一个守护进程集，在每个节点上生成一个pod，该pod读取由kubelet、容器运行时和容器生成的日志，并将它们发送到ElasticSearch。

安装部署

1.下载

[root@elasticsearch01 yaml]# git clone https://github.com/kiwigrid/helm-charts
Cloning into 'helm-charts'...
remote: Enumerating objects: 33, done.
remote: Counting objects: 100% (33/33), done.
remote: Compressing objects: 100% (23/23), done.
remote: Total 1062 (delta 13), reused 25 (delta 10), pack-reused 1029
Receiving objects: 100% (1062/1062), 248.83 KiB | 139.00 KiB/s, done.
Resolving deltas: 100% (667/667), done.


[root@elasticsearch01 yaml]# cd helm-charts/fluentd-elasticsearch
[root@elasticsearch01 fluentd-elasticsearch]# ls
Chart.yaml  OWNERS  README.md  templates  values.yaml

2.修改values.yaml配置
主要修改fluentd镜像地址、elasticsearch地址、index前缀等信息

[root@elasticsearch01 fluentd-elasticsearch]# cat values.yaml |grep -Ev "^#|^$"
image:
  repository: registry.cn-beijing.aliyuncs.com/minminmsn/fluentd-elasticsearch
  tag: v2.5.2
  pullPolicy: IfNotPresent
  ## Optionally specify an array of imagePullSecrets.
  ## Secrets must be manually created in the namespace.
  ## ref: https://kubernetes.io/docs/tasks/configure-pod-container/pull-image-private-registry/
  ##
  # pullSecrets:
  #   - myRegistrKeySecretName
awsSigningSidecar:
  enabled: false
  image:
    repository: abutaha/aws-es-proxy
    tag: 0.9
priorityClassName: ""
hostLogDir:
  varLog: /var/log
  dockerContainers: /var/lib/docker/containers
  libSystemdDir: /usr/lib64
resources: {}
  # limits:
  #   cpu: 100m
  #   memory: 500Mi
  # requests:
  #   cpu: 100m
  #   memory: 200Mi
elasticsearch:
  auth:
    enabled: false
    user: "yourUser"
    password: "yourPass"
  buffer_chunk_limit: 2M
  buffer_queue_limit: 8
  host: '10.2.8.44'
  logstash_prefix: 'logstash'
  port: 9200
  scheme: 'http'
  ssl_version: TLSv1_2
fluentdArgs: "--no-supervisor -q"
env:
  # OUTPUT_USER: my_user
  # LIVENESS_THRESHOLD_SECONDS: 300
  # STUCK_THRESHOLD_SECONDS: 900
secret:
rbac:
  create: true
serviceAccount:
  # Specifies whether a ServiceAccount should be created
  create: true
  # The name of the ServiceAccount to use.
  # If not set and create is true, a name is generated using the fullname template
  name: ""
podSecurityPolicy:
  enabled: false
  annotations: {}
    ## Specify pod annotations
    ## Ref: https://kubernetes.io/docs/concepts/policy/pod-security-policy/#apparmor
    ## Ref: https://kubernetes.io/docs/concepts/policy/pod-security-policy/#seccomp
    ## Ref: https://kubernetes.io/docs/concepts/policy/pod-security-policy/#sysctl
    ##
    # seccomp.security.alpha.kubernetes.io/allowedProfileNames: '*'
    # seccomp.security.alpha.kubernetes.io/defaultProfileName: 'docker/default'
    # apparmor.security.beta.kubernetes.io/defaultProfileName: 'runtime/default'
livenessProbe:
  enabled: true
annotations: {}
podAnnotations: {}
  # prometheus.io/scrape: "true"
  # prometheus.io/port: "24231"
updateStrategy:
  type: RollingUpdate
tolerations: {}
  # - key: node-role.kubernetes.io/master
  #   operator: Exists
  #   effect: NoSchedule
affinity: {}
  # nodeAffinity:
  #   requiredDuringSchedulingIgnoredDuringExecution:
  #     nodeSelectorTerms:
  #     - matchExpressions:
  #       - key: node-role.kubernetes.io/master
  #         operator: DoesNotExist
nodeSelector: {}
service: {}
  # type: ClusterIP
  # ports:
  #   - name: "monitor-agent"
  #     port: 24231
serviceMonitor:
  ## If true, a ServiceMonitor CRD is created for a prometheus operator
  ## https://github.com/coreos/prometheus-operator
  ##
  enabled: false
  interval: 10s
  path: /metrics
  labels: {}
prometheusRule:
  ## If true, a PrometheusRule CRD is created for a prometheus operator
  ## https://github.com/coreos/prometheus-operator
  ##
  enabled: false
  prometheusNamespace: monitoring
  labels: {}
  #  role: alert-rules
configMaps:
  useDefaults:
    systemConf: true
    containersInputConf: true
    systemInputConf: true
    forwardInputConf: true
    monitoringConf: true
    outputConf: true
extraConfigMaps:
  # system.conf: |-
  #   <system>
  #     root_dir /tmp/fluentd-buffers/
  #   </system>

3.helm安装fluentd

[root@elasticsearch01 fluentd-elasticsearch]# helm  install .
NAME:   sanguine-dragonfly
LAST DEPLOYED: Thu Jun  6 16:07:55 2019
NAMESPACE: default
STATUS: DEPLOYED

RESOURCES:
==> v1/ServiceAccount
NAME                                      SECRETS  AGE
sanguine-dragonfly-fluentd-elasticsearch  0        0s

==> v1/ClusterRole
NAME                                      AGE
sanguine-dragonfly-fluentd-elasticsearch  0s

==> v1/ClusterRoleBinding
NAME                                      AGE
sanguine-dragonfly-fluentd-elasticsearch  0s

==> v1/DaemonSet
NAME                                      DESIRED  CURRENT  READY  UP-TO-DATE  AVAILABLE  NODE SELECTOR  AGE
sanguine-dragonfly-fluentd-elasticsearch  0        0        0      0           0          <none>         0s

==> v1/ConfigMap
NAME                                      DATA  AGE
sanguine-dragonfly-fluentd-elasticsearch  6     0s


NOTES:
1. To verify that Fluentd has started, run:

  kubectl --namespace=default get pods -l "app.kubernetes.io/name=fluentd-elasticsearch,app.kubernetes.io/instance=sanguine-dragonfly"

THIS APPLICATION CAPTURES ALL CONSOLE OUTPUT AND FORWARDS IT TO elasticsearch . Anything that might be identifying,
including things like IP addresses, container images, and object names will NOT be anonymized.

4.检查安装效果

[root@elasticsearch01 fluentd-elasticsearch]# kubectl get pods |grep flu
sanguine-dragonfly-fluentd-elasticsearch-hrxbp   1/1     Running   0          26m
sanguine-dragonfly-fluentd-elasticsearch-jcznt   1/1     Running   0          26m

Elasticstack操作

1.Elasticsearch
elasticsearch上会生成logstash-2019.06.06样式的index，默认按天生产，前缀logstash是values.yaml配置文件里设置的

2.Kibana
Management--Create Index Pattern--logstash-2019*--Discover