Kubernetes 学习9 Pod控制器

[root@k8smaster manifests]# kubectl explain deploy（也可以写作deployment）
KIND:     Deployment
VERSION:  extensions/v1beta1 #属于该群组，但是1.10包括1.11版本中其已经被摞到另外一个群组 apps/v1 版中，因此这个文档的版本是落后于我们k8s自身的。

DESCRIPTION:
     DEPRECATED - This group version of Deployment is deprecated by
     apps/v1beta2/Deployment. #此版本也是老版的，当前1.11版本为apps/v1  See the release notes for more information.
     Deployment enables declarative updates for Pods and ReplicaSets.

FIELDS:
   apiVersion    <string>
     APIVersion defines the versioned schema of this representation of an
     object. Servers should convert recognized schemas to the latest internal
     value, and may reject unrecognized values. More info:
     https://git.k8s.io/community/contributors/devel/api-conventions.md#resources

   kind    <string>
     Kind is a string value representing the REST resource this object
     represents. Servers may infer this from the endpoint the client submits
     requests to. Cannot be updated. In CamelCase. More info:
     https://git.k8s.io/community/contributors/devel/api-conventions.md#types-kinds

   metadata    <Object>
     Standard object metadata.

   spec    <Object>
     Specification of the desired behavior of the Deployment.

   status    <Object>
     Most recently observed status of the Deployment.

[root@k8smaster manifests]# kubectl explain deployment.spec
KIND:     Deployment
VERSION:  extensions/v1beta1

RESOURCE: spec <Object>

DESCRIPTION:
     Specification of the desired behavior of the Deployment.

     DeploymentSpec is the specification of the desired behavior of the
     Deployment.

FIELDS:
   minReadySeconds    <integer>
     Minimum number of seconds for which a newly created pod should be ready
     without any of its container crashing, for it to be considered available.
     Defaults to 0 (pod will be considered available as soon as it is ready)

   paused    <boolean> #暂停，默认都是不暂停的上来就更新
     Indicates that the deployment is paused and will not be processed by the
     deployment controller.

   progressDeadlineSeconds    <integer>
     The maximum time in seconds for a deployment to make progress before it is
     considered to be failed. The deployment controller will continue to process
     failed deployments and a condition with a ProgressDeadlineExceeded reason
     will be surfaced in the deployment status. Note that progress will not be
     estimated during the time a deployment is paused. This is not set by
     default.

   replicas    <integer>
     Number of desired pods. This is a pointer to distinguish between explicit
     zero and not specified. Defaults to 1.

   revisionHistoryLimit    <integer> #我们在滚动更新中最多在历史中保存过去多少个历史版本，默认为10个
     The number of old ReplicaSets to retain to allow rollback. This is a
     pointer to distinguish between explicit zero and not specified.

   rollbackTo    <Object>
     DEPRECATED. The config this deployment is rolling back to. Will be cleared
     after rollback is done.

   selector    <Object>
     Label selector for pods. Existing ReplicaSets whose pods are selected by
     this will be the ones affected by this deployment.

   strategy    <Object> #更新策略
     The deployment strategy to use to replace existing pods with new ones.

   template    <Object> -required-
     Template describes the pods that will be created.

[root@k8smaster manifests]# kubectl explain deployment.spec.strategy
KIND:     Deployment
VERSION:  extensions/v1beta1

RESOURCE: strategy <Object>

DESCRIPTION:
     The deployment strategy to use to replace existing pods with new ones.

     DeploymentStrategy describes how to replace existing pods with new ones.

FIELDS:
   rollingUpdate    <Object> #滚动更新
     Rolling update config params. Present only if DeploymentStrategyType =
     RollingUpdate.

   type    <string>
     Type of deployment. Can be "Recreate" or "RollingUpdate". Default is
     RollingUpdate. #重建式更新Recreate，还有滚动更新RollingUpdate，若使用RollingUpdate，还可以控制更新粒度

[root@k8smaster manifests]# kubectl explain deployment.spec.strategy.rollingUpdate
KIND:     Deployment
VERSION:  extensions/v1beta1

RESOURCE: rollingUpdate <Object>

DESCRIPTION:
     Rolling update config params. Present only if DeploymentStrategyType =
     RollingUpdate.

     Spec to control the desired behavior of rolling update.

FIELDS:
   maxSurge    <string> #对应的更新过程中最多能超出所指定的目标副本数有几个，有两种取值方式，第一直接指定数量，第二百分比。     
The maximum number of pods that can be scheduled above the desired number
     of pods. Value can be an absolute number (ex: 5) or a percentage of desired
     pods (ex: 10%). This can not be 0 if MaxUnavailable is 0. Absolute number
     is calculated from percentage by rounding up. By default, a value of 1 is
     used. Example: when this is set to 30%, the new RC can be scaled up
     immediately when the rolling update starts, such that the total number of
     old and new pods do not exceed 130% of desired pods. Once old pods have
     been killed, new RC can be scaled up further, ensuring that total number of
     pods running at any time during the update is atmost 130% of desired pods.

   maxUnavailable    <string>#表示最多有几个不可用和上述一样也是两种取值方式
     The maximum number of pods that can be unavailable during the update. Value
     can be an absolute number (ex: 5) or a percentage of desired pods (ex:
     10%). Absolute number is calculated from percentage by rounding down. This
     can not be 0 if MaxSurge is 0. By default, a fixed value of 1 is used.
     Example: when this is set to 30%, the old RC can be scaled down to 70% of
     desired pods immediately when the rolling update starts. Once new pods are
     ready, old RC can be scaled down further, followed by scaling up the new
     RC, ensuring that the total number of pods available at all times during
     the update is at least 70% of desired pods.