logging - FluentD 日志不可读。它被排除在外，下次会检查

Question

面对:流利的日志不可读。它被排除在外，下次会检查

我有一个在 kubernetes 设置中运行的 fluentD 守护程序集的简单配置。

流利版: fluentd-0.12.43

下面是我的配置。

  <source>
    @type tail
    path /var/log/containers/sample*.log
    time_format %Y-%m-%dT%H:%M:%S.%NZ
    tag sample.*
    format json
    read_from_head true
  </source>
  <match sample.**>
    @type forward
    heartbeat_type tcp
    send_timeout 60s
    recover_wait 10s
    hard_timeout 60s
    <server>
      name worker-node2
      host 10.32.0.15
      port 24224
      weight 60
    </server>
  </match>

低于警告且不转发任何日志

2018-08-03 06:36:53 +0000 [warn]: /var/log/containers/samplelog-79bd66868b-t7xn9_logging1_fluentd-70e85c5d6328e7d.log unreadable. It is excluded and would be examined next time.

2018-08-03 06:37:53 +0000 [warn]: /var/log/containers/samplelog-79bd66868b-t7xn9_logging1_fluentd-70e85c5bc89ab24.log unreadable. It is excluded and would be examined next time.

日志文件权限:

[root@k8s-master fluentd-daemonset]# ls -lrt **/var/log/containers/**

**lrwxrwxrwx** Jun 25 06:25 sample-77g68_kube-system_kube-proxy-9f3c3951c32ee.log 
-> /var/log/pods/aa1f8d5b-746f-11e8-95c0-005056b9ff3a/sample/7.log

守护程序集的 YAML 文件具有安装说明:

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: fluentd
  namespace: logging1
  labels:
    k8s-app: fluentd-logging
    version: v1
    kubernetes.io/cluster-service: "true"
spec:
  template:
    -----
    -----
    -----

        volumeMounts:
        - name: fluentd-config
          mountPath: /fluentd/etc/ 
        - name: varlog
          mountPath: /var/log
          readOnly: true
        - name: varlogpods
          mountPath: /var/log/pods
          readOnly: true
        - name: varlogcontainers
          mountPath: /var/log/containers
          readOnly: true
        - name: varlibdocker
          mountPath: /var/lib/docker
          readOnly: true
        - name: varlibdockercontainers
          mountPath: /var/lib/docker/containers
          readOnly: true
      terminationGracePeriodSeconds: 30
      volumes:
      - name: fluentd-config
        configMap:
          name: fluentd-config
      - name: varlog
        hostPath:
          path: /var/log
      - name: varlogpods
        hostPath:
          path: /var/log/pods
      - name: varlogcontainers
        hostPath:
          path: /var/log/containers
      - name: varlibdocker
        hostPath:
          path: /var/lib/docker
      - name: varlibdockercontainers
        hostPath:
          path: /var/lib/docker/containers 

即使 权限正确 , fluentD版本正确 , 挂载指令是他们在 kubernetes 守护进程中的 ，为什么我会收到此警告。

Answer 1

我遇到了类似的问题。
所以，实际发生的是——
1. Fluentd 在/var/log/containers/中创建符号链接(symbolic link)，这进一步是/var/log/pods/中文件的符号链接(symbolic link)，例如 -

root@fluentd-forwarders-5bfzm:/home/fluent# ls -ltr /var/log/containers/consul-0_default_consul-c4dbf47bf46b4cacfb0db67885fdba73835e05b45b14ec7dc746cc2d5ed92ea3.log 
lrwxrwxrwx. 1 root root 83 Oct 30 07:42 /var/log/containers/consul-0_default_consul-c4dbf47bf46b4cacfb0db67885fdba73835e05b45b14ec7dc746cc2d5ed92ea3.log -> /var/log/pods/default_consul-0_2a206546-73b3-4d05-bd7a-0b307c8b24d1/consul/1628.log

2./var/log/pods 是挂载在主机上的日志文件的符号链接(symbolic link)。在我的设置中，我使用主机/节点的/data/目录来存储 docker 数据。

root@fluentd-forwarders-5bfzm:/home/fluent# ls -ltr /var/log/pods/default_consul-0_2a206546-73b3-4d05-bd7a-0b307c8b24d1/consul/1629.log 
lrwxrwxrwx. 1 root root 162 Oct 30 07:47 /var/log/pods/default_consul-0_2a206546-73b3-4d05-bd7a-0b307c8b24d1/consul/1629.log -> /data/docker/containers/478642a56a6e15e7398391a2526ec52ad1aa24341e95aa32063163da11f4cc8b/478642a56a6e15e7398391a2526ec52ad1aa24341e95aa32063163da11f4cc8b-json.log

因此，在我的 deployment.yaml 中，我必须挂载/data/docker/containers 而不是/var/lib/containers/来解决问题，即

        volumeMounts:
        - mountPath: /var/log
          name: varlog
        - mountPath: /data/docker/containers
          name: datadockercontainers
          readOnly: true
        - mountPath: /fluentd/etc
          name: config-path