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date: 2020-06-23 19:10

# 在 k8s 中部署 ES 时权限不足导致 pod CrashLoopBackOff

在 k8s 中通过 helm 来部署 ES 时，master 相关 Pod 与 data 相关 Pod 的状态为 CrashLoopBackOff。

部署 ES 选择了 bitnami 的 Chart

$ helm install es bitnami/elasticsearch --values values.yaml

部署了一个 master 节点一个 data 节点 并通过 HostPath 作为挂载

global:
  storageClass: local-storage
master:
  replicas: 1
data:
  replicas: 1

关于 HostPath 的 PV 配置文件如下，挂载到目录 /mnt/k8s-data/es/master

apiVersion: v1
kind: PersistentVolume
metadata:
  name: local-es-pv-master
  labels:
    type: local
spec:
  storageClassName: local-storage
  capacity:
    storage: 8Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/mnt/k8s-data/es/master"

# 捉虫

通过 kubectl describe 查看节点并无异常

$ kubectl describe pod es-elasticsearch-master-0

继续通过 kubectl logs，查看 POD 日志

$ kubectl logs es-elasticsearch-master-0
 07:41:46.42
 07:41:46.42 Welcome to the Bitnami elasticsearch container
 07:41:46.42 Subscribe to project updates by watching https://github.com/bitnami/bitnami-docker-elasticsearch
 07:41:46.42 Submit issues and feature requests at https://github.com/bitnami/bitnami-docker-elasticsearch/issues
 07:41:46.43
 07:41:46.43 INFO  ==> ** Starting Elasticsearch setup **
 07:41:46.46 INFO  ==> Configuring/Initializing Elasticsearch...
 07:41:46.49 INFO  ==> Setting default configuration
 07:41:46.51 INFO  ==> Configuring Elasticsearch cluster settings...
OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release.

 07:41:49.32 INFO  ==> ** Elasticsearch setup finished! **
 07:41:49.34 INFO  ==> ** Starting Elasticsearch **
OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release.
[2020-06-23T03:24:09,855][ERROR][o.e.b.ElasticsearchUncaughtExceptionHandler] [es-elasticsearch-master-0] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: ElasticsearchException[failed to bind service]; nested: AccessDeniedException[/bitnami/elasticsearch/data/nodes];

# 原因

通过 HostPath 挂载的目录没有访问权限

# 解决

$ cd /mnt/k8s-data/es/master

$ chmod -R 777 .

# 总结

当碰到 k8s pod 出现问题时，日志最为关键，找问题关键两步

kubectl describe pod
kubectl logs

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