容器组（Pod） 容器组（Pod）是Kubernetes创建或部署的最小单位。一个Pod封装一个或多个容器（container）、存储资源（volume）、一个独立的网络IP以及管理控制容器运行方式的策略选项。 Pod使用主要分为两种方式： Pod中运行一个容器。这是Kubernetes最常见的用法，您可以将Pod视为单个封装的容器，但是Kubernetes是直接管理Pod而不是容器。 Pod中运行多个需要耦合在一起工作、需要共享资源的容器。通常这种场景下应用包含一个主容器和几个辅助容器（SideCar Container），如图1所示，例如主容器为一个web服务器，从一个固定目录下对外提供文件服务，而辅助容器周期性的从外部下载文件存到这个固定目录下。 图1 Pod 实际使用中很少直接创建Pod，而是使用Kubernetes中称为Controller的抽象层来管理Pod实例，例如Deployment和Job。Controller可以创建和管理多个Pod，提供副本管理、滚动升级和自愈能力。通常，Controller会使用Pod Template来创建相应的Pod。

使用环境变量 环境变量是容器运行环境中设定的一个变量。 环境变量为应用提供极大的灵活性，您可以在应用程序中使用环境变量，在创建容器时为环境变量赋值，容器运行时读取环境变量的值，从而做到灵活的配置，而不是每次都重新编写应用程序制作镜像。 环境变量的使用方法如下所示，配置spec.containers.env字段即可。 apiVersion: v1 kind: Pod metadata: name: nginx spec: containers: - image: nginx:alpine name: container-0 resources: limits: cpu: 100m memory: 200Mi requests: cpu: 100m memory: 200Mi env: # 环境变量 - name: env_key value: env_value imagePullSecrets: - name: default-secret 执行如下命令查看容器中的环境变量，可以看到env_key这个环境变量，其值为env_value。 $ kubectl exec -it nginx -- env PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin HOSTNAME=nginx TERM=xterm env_key=env_value 环境变量还可以引用ConfigMap和Secret，具体使用方法请参见在环境变量中引用ConfigMap和在环境变量中引用Secret。

容器启动命令 启动容器就是启动主进程，但有些时候，启动主进程前，需要一些准备工作。比如MySQL类的数据库，可能需要一些数据库配置、初始化的工作，这些工作要在最终的MySQL服务器运行之前做完。这些操作，可以在制作镜像时通过在Dockerfile文件中设置ENTRYPOINT或CMD来完成，如下所示的Dockerfile中设置了ENTRYPOINT ["top", "-b"]命令，其将会在容器启动时执行。 FROM ubuntu ENTRYPOINT ["top", "-b"] 实际使用时，只需配置Pod的containers.command参数，该参数是list类型，第一个参数为执行命令，后面均为命令的参数。 apiVersion: v1 kind: Pod metadata: name: nginx spec: containers: - image: nginx:alpine name: container-0 resources: limits: cpu: 100m memory: 200Mi requests: cpu: 100m memory: 200Mi command: # 启动命令 - top - "-b" imagePullSecrets: - name: default-secret

容器的生命周期 Kubernetes提供了容器生命周期钩子，在容器的生命周期的特定阶段执行调用，比如容器在停止前希望执行某项操作，就可以注册相应的钩子函数。目前提供的生命周期钩子函数如下所示。 启动后处理（PostStart）：容器启动后触发。 停止前处理（PreStop）：容器停止前触发。 实际使用时，只需配置Pod的lifecycle.postStart或lifecycle.preStop参数，如下所示。 apiVersion: v1 kind: Pod metadata: name: nginx spec: containers: - image: nginx:alpine name: container-0 resources: limits: cpu: 100m memory: 200Mi requests: cpu: 100m memory: 200Mi lifecycle: postStart: # 启动后处理 exec: command: - "/postStart.sh" preStop: # 停止前处理 exec: command: - "/preStop.sh" imagePullSecrets: - name: default-secret

创建Pod kubernetes中资源可以使用YAML描述（如果您对YAML格式不了解，可以参考YAML语法），也可以使用JSON，如下示例描述了一个名为nginx的Pod，这个Pod中包含一个名为container-0的容器，使用nginx:alpine镜像，使用的资源为100m CPU、200Mi内存。 apiVersion: v1 # Kubernetes的API Version kind: Pod # Kubernetes的资源类型 metadata: name: nginx # Pod的名称 spec: # Pod的具体规格（specification） containers: - image: nginx:alpine # 使用的镜像为 nginx:alpine name: container-0 # 容器的名称 resources: # 申请容器所需的资源 limits: cpu: 100m memory: 200Mi requests: cpu: 100m memory: 200Mi imagePullSecrets: # 拉取镜像使用的证书，在CCE上必须为default-secret - name: default-secret 如上面YAML的注释，YAML描述文件主要为如下部分： metadata：一些名称/标签/namespace等信息。 spec：Pod实际的配置信息，包括使用什么镜像，volume等。 如果去查询Kubernetes的资源，您会看到还有一个status字段，status描述kubernetes资源的实际状态，创建时不需要配置。这个示例是一个最小集，其他参数定义后面会逐步介绍。 Pod定义好后就可以使用kubectl创建，如果上面YAML文件名称为nginx.yaml，则创建命令如下所示，-f表示使用文件方式创建。 $ kubectl create -f nginx.yaml pod/nginx created

状态码 状态码 描述 200 OK 202 Accepted 400 BadRequest 401 Unauthorized 403 Forbidden 404 NotFound 405 MethodNotAllowed 406 NotAcceptable 409 Conflict 415 UnsupportedMediaType 422 Invalid 429 TooManyRequests 500 InternalError 503 ServiceUnavailable 504 ServerTimeout

请求参数 表3 请求Header参数 参数 是否必选 参数类型 描述 X-Auth-Token 是 String 用户Token。 通过调用 IAM 服务获取用户Token接口获取（响应消息头中X-Subject-Token的值）。 Content-Type 是 String 消息体的类型（格式），默认取值为“application/json” 缺省值：application/json 表4 请求Body参数 参数 是否必选 参数类型 描述 apiVersion 否 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/sig-architecture/api-conventions.md#resources dryRun 否 Array of strings When present, indicates that modifications should not be persisted. An invalid or unrecognized dryRun directive will result in an error response and no further processing of the request. Valid values are: - All: all dry run stages will be processed gracePeriodSeconds 否 Long The duration in seconds before the object should be deleted. Value must be non-negative integer. The value zero indicates delete immediately. If this value is nil, the default grace period for the specified type will be used. Defaults to a per object value if not specified. zero means delete immediately. kind 否 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/sig-architecture/api-conventions.md#types-kinds orphanDependents 否 Boolean Deprecated: please use the PropagationPolicy, this field will be deprecated in 1.7. Should the dependent objects be orphaned. If true/false, the "orphan" finalizer will be added to/removed from the object's finalizers list. Either this field or PropagationPolicy may be set, but not both. preconditions 否 io.k8s.apimachinery.pkg.apis.meta.v1.Preconditions object Must be fulfilled before a deletion is carried out. If not possible, a 409 Conflict status will be returned. propagationPolicy 否 String Whether and how garbage collection will be performed. Either this field or OrphanDependents may be set, but not both. The default policy is decided by the existing finalizer set in the metadata.finalizers and the resource-specific default policy. Acceptable values are: 'Orphan' - orphan the dependents; 'Background' - allow the garbage collector to delete the dependents in the background; 'Foreground' - a cascading policy that deletes all dependents in the foreground. 表5 io.k8s.apimachinery.pkg.apis.meta.v1.Preconditions 参数 是否必选 参数类型 描述 resourceVersion 否 String Specifies the target ResourceVersion uid 否 String Specifies the target UID.

响应参数 状态码： 200 表6 响应Body参数 参数 参数类型 描述 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/sig-architecture/api-conventions.md#resources code Integer Suggested HTTP return code for this status, 0 if not set. details io.k8s.apimachinery.pkg.apis.meta.v1.StatusDetails object Extended data associated with the reason. Each reason may define its own extended details. This field is optional and the data returned is not guaranteed to conform to any schema except that defined by the reason type. 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/sig-architecture/api-conventions.md#types-kinds message String A human-readable description of the status of this operation. metadata io.k8s.apimachinery.pkg.apis.meta.v1.ListMeta object Standard list metadata. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds reason String A machine-readable description of why this operation is in the "Failure" status. If this value is empty there is no information available. A Reason clarifies an HTTP status code but does not override it. status String Status of the operation. One of: "Success" or "Failure". More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status 表7 io.k8s.apimachinery.pkg.apis.meta.v1.StatusDetails 参数 参数类型 描述 causes Array of io.k8s.apimachinery.pkg.apis.meta.v1.StatusCause objects The Causes array includes more details associated with the StatusReason failure. Not all StatusReasons may provide detailed causes. group String The group attribute of the resource associated with the status StatusReason. kind String The kind attribute of the resource associated with the status StatusReason. On some operations may differ from the requested resource Kind. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds name String The name attribute of the resource associated with the status StatusReason (when there is a single name which can be described). retryAfterSeconds Integer If specified, the time in seconds before the operation should be retried. Some errors may indicate the client must take an alternate action for those errors this field may indicate how long to wait before taking the alternate action. uid String UID of the resource. (when there is a single resource which can be described). More info: http://kubernetes.io/docs/user-guide/identifiers#uids 表8 io.k8s.apimachinery.pkg.apis.meta.v1.StatusCause 参数 参数类型 描述 field String The field of the resource that has caused this error, as named by its JSON serialization. May include dot and postfix notation for nested attributes. Arrays are zero-indexed. Fields may appear more than once in an array of causes due to fields having multiple errors. Optional. Examples: "name" - the field "name" on the current resource "items[0].name" - the field "name" on the first array entry in "items" message String A human-readable description of the cause of the error. This field may be presented as-is to a reader. reason String A machine-readable description of the cause of the error. If this value is empty there is no information available. 表9 io.k8s.apimachinery.pkg.apis.meta.v1.ListMeta 参数 参数类型 描述 continue String continue may be set if the user set a limit on the number of items returned, and indicates that the server has more data available. The value is opaque and may be used to issue another request to the endpoint that served this list to retrieve the next set of available objects. Continuing a consistent list may not be possible if the server configuration has changed or more than a few minutes have passed. The resourceVersion field returned when using this continue value will be identical to the value in the first response, unless you have received this token from an error message. remainingItemCount Long remainingItemCount is the number of subsequent items in the list which are not included in this list response. If the list request contained label or field selectors, then the number of remaining items is unknown and the field will be left unset and omitted during serialization. If the list is complete (either because it is not chunking or because this is the last chunk), then there are no more remaining items and this field will be left unset and omitted during serialization. Servers older than v1.15 do not set this field. The intended use of the remainingItemCount is estimating the size of a collection. Clients should not rely on the remainingItemCount to be set or to be exact. resourceVersion String String that identifies the server's internal version of this object that can be used by clients to determine when objects have changed. Value must be treated as opaque by clients and passed unmodified back to the server. Populated by the system. Read-only. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#concurrency-control-and-consistency selfLink String selfLink is a URL representing this object. Populated by the system. Read-only. DEPRECATED Kubernetes will stop propagating this field in 1.20 release and the field is planned to be removed in 1.21 release. 状态码： 202 表10 响应Body参数 参数 参数类型 描述 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/sig-architecture/api-conventions.md#resources code Integer Suggested HTTP return code for this status, 0 if not set. details io.k8s.apimachinery.pkg.apis.meta.v1.StatusDetails object Extended data associated with the reason. Each reason may define its own extended details. This field is optional and the data returned is not guaranteed to conform to any schema except that defined by the reason type. 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/sig-architecture/api-conventions.md#types-kinds message String A human-readable description of the status of this operation. metadata io.k8s.apimachinery.pkg.apis.meta.v1.ListMeta object Standard list metadata. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds reason String A machine-readable description of why this operation is in the "Failure" status. If this value is empty there is no information available. A Reason clarifies an HTTP status code but does not override it. status String Status of the operation. One of: "Success" or "Failure". More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status 表11 io.k8s.apimachinery.pkg.apis.meta.v1.StatusDetails 参数 参数类型 描述 causes Array of io.k8s.apimachinery.pkg.apis.meta.v1.StatusCause objects The Causes array includes more details associated with the StatusReason failure. Not all StatusReasons may provide detailed causes. group String The group attribute of the resource associated with the status StatusReason. kind String The kind attribute of the resource associated with the status StatusReason. On some operations may differ from the requested resource Kind. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds name String The name attribute of the resource associated with the status StatusReason (when there is a single name which can be described). retryAfterSeconds Integer If specified, the time in seconds before the operation should be retried. Some errors may indicate the client must take an alternate action for those errors this field may indicate how long to wait before taking the alternate action. uid String UID of the resource. (when there is a single resource which can be described). More info: http://kubernetes.io/docs/user-guide/identifiers#uids 表12 io.k8s.apimachinery.pkg.apis.meta.v1.StatusCause 参数 参数类型 描述 field String The field of the resource that has caused this error, as named by its JSON serialization. May include dot and postfix notation for nested attributes. Arrays are zero-indexed. Fields may appear more than once in an array of causes due to fields having multiple errors. Optional. Examples: "name" - the field "name" on the current resource "items[0].name" - the field "name" on the first array entry in "items" message String A human-readable description of the cause of the error. This field may be presented as-is to a reader. reason String A machine-readable description of the cause of the error. If this value is empty there is no information available. 表13 io.k8s.apimachinery.pkg.apis.meta.v1.ListMeta 参数 参数类型 描述 continue String continue may be set if the user set a limit on the number of items returned, and indicates that the server has more data available. The value is opaque and may be used to issue another request to the endpoint that served this list to retrieve the next set of available objects. Continuing a consistent list may not be possible if the server configuration has changed or more than a few minutes have passed. The resourceVersion field returned when using this continue value will be identical to the value in the first response, unless you have received this token from an error message. remainingItemCount Long remainingItemCount is the number of subsequent items in the list which are not included in this list response. If the list request contained label or field selectors, then the number of remaining items is unknown and the field will be left unset and omitted during serialization. If the list is complete (either because it is not chunking or because this is the last chunk), then there are no more remaining items and this field will be left unset and omitted during serialization. Servers older than v1.15 do not set this field. The intended use of the remainingItemCount is estimating the size of a collection. Clients should not rely on the remainingItemCount to be set or to be exact. resourceVersion String String that identifies the server's internal version of this object that can be used by clients to determine when objects have changed. Value must be treated as opaque by clients and passed unmodified back to the server. Populated by the system. Read-only. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#concurrency-control-and-consistency selfLink String selfLink is a URL representing this object. Populated by the system. Read-only. DEPRECATED Kubernetes will stop propagating this field in 1.20 release and the field is planned to be removed in 1.21 release.

URI DELETE /api/v1/namespaces/{name} 表1 路径参数 参数 是否必选 参数类型 描述 name 是 String name of the Namespace 表2 Query参数 参数 是否必选 参数类型 描述 dryRun 否 String When present, indicates that modifications should not be persisted. An invalid or unrecognized dryRun directive will result in an error response and no further processing of the request. Valid values are: - All: all dry run stages will be processed gracePeriodSeconds 否 Integer The duration in seconds before the object should be deleted. Value must be non-negative integer. The value zero indicates delete immediately. If this value is nil, the default grace period for the specified type will be used. Defaults to a per object value if not specified. zero means delete immediately. orphanDependents 否 Boolean Deprecated: please use the PropagationPolicy, this field will be deprecated in 1.7. Should the dependent objects be orphaned. If true/false, the "orphan" finalizer will be added to/removed from the object's finalizers list. Either this field or PropagationPolicy may be set, but not both. propagationPolicy 否 String Whether and how garbage collection will be performed. Either this field or OrphanDependents may be set, but not both. The default policy is decided by the existing finalizer set in the metadata.finalizers and the resource-specific default policy. Acceptable values are: 'Orphan' - orphan the dependents; 'Background' - allow the garbage collector to delete the dependents in the background; 'Foreground' - a cascading policy that deletes all dependents in the foreground. pretty 否 String If 'true', then the output is pretty printed.