pod的状态及操作
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查看pod的标签
[root@master pod]# kubectl get pods --show-labels NAME READY STATUS RESTARTS AGE LABELS cv-podh 1/2 CrashLoopBackOff 15 55m app=myapp,tier=frontend mysql-gh9ds 1/1 Running 4 28h app=mysql,cx=z pod 1/2 CrashLoopBackOff 70 27h app=myapp,tier=frontend
给pod添加标签
[root@master pod]# kubectl label pods mysql-gh9ds sql=3306 pod/mysql-gh9ds labeled [root@master pod]# kubectl get pods -l sql=3306 --show-labels NAME READY STATUS RESTARTS AGE LABELS mysql-gh9ds 1/1 Running 4 28h app=mysql,cx=z,sql=3306
修改pod标签
[root@master pod]# kubectl label pods mysql-gh9ds --overwrite sql=321 pod/mysql-gh9ds labeled [root@master pod]# kubectl get pods --show-labels -l sql=321 NAME READY STATUS RESTARTS AGE LABELS mysql-gh9ds 1/1 Running 4 28h app=mysql,cx=z,sql=321
给节点打标签
[root@master ~]# kubectl label nodes node01 hg=192.167.10.20 node/node01 labeled [root@master ~]# kubectl get nodes --show-labels -l hg NAME STATUS ROLES AGE VERSION LABELS node01 Ready <none> 23d v1.17.0 01=192.168.10.21,beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,hg=192.167.10.20,kubernetes.io /arch=amd64,kubernetes.io/hostname=node01,kubernetes.io/os=linux
给节点修改标签
[root@master ~]# kubectl label nodes node01 --overwrite hg=192.167.10.2 node/node01 labeled
pod 节点标签选择器
nodeName <string> 节点名称 nodeSelector <map[string]string> 通过标签选择 key v集合
示例
apiVersion: v1
kind: ReplicationController
metadata:
name: mysql
spec:
replicas: 1
selector:
app: mysql
template:
metadata:
labels:
app: mysql
spec:
containers:
- name: mysql
image: mysql
ports:
- containerPort: 3306
env:
- name: MYSQL_ROOT_PASSWORD
value: "123456"
nodeSelector:
cx: ssd
kubectl label nodes node01 cx=ssd
[root@master pod]# kubectl create -f s.yaml
replicationcontroller/mysql created
[root@master pod]# kubectl get pods
NAME READY STATUS RESTARTS AGE
cv-podh 1/2 CrashLoopBackOff 51 26h
mysql-dswc4 1/1 Running 0 17s
pod 1/2 CrashLoopBackOff 106 2d4h
[root@master pod]# kubectl describe mysql-dswc4
error: the server doesn‘t have a resource type "mysql-dswc4"
[root@master pod]# kubectl describe pods mysql-dswc4
Name: mysql-dswc4
Namespace: default
Priority: 0
Node: node01/192.168.10.21
Start Time: Mon, 20 Jan 2020 16:19:10 +0800
Labels: app=mysql
Annotations: <none>
Status: Running
IP: 10.244.1.14
IPs:
IP: 10.244.1.14
Controlled By: ReplicationController/mysql
Containers:
mysql:
Container ID: docker://b9bdd898c1bbc3bd5afe10f44cf3c2846242e308973040958f57a2c87da6bde2
Image: mysql
Image ID: docker-pullable://mysql@sha256:f1df505c4c6e8eae599a0482e3bde3e761cd700c00cbc371a8161648a26817c0
Port: 3306/TCP
Host Port: 0/TCP
State: Running
Started: Mon, 20 Jan 2020 16:19:15 +0800
Ready: True
Restart Count: 0
Environment:
MYSQL_ROOT_PASSWORD: 123456
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-5wzsb (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
default-token-5wzsb:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-5wzsb
Optional: false
QoS Class: BestEffort
Node-Selectors: cx=ssd
Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s
node.kubernetes.io/unreachable:NoExecute for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 62s default-scheduler Successfully assigned default/mysql-dswc4 to node01
Normal Pulling 61s kubelet, node01 Pulling image "mysql"
Normal Pulled 57s kubelet, node01 Successfully pulled image "mysql"
Normal Created 57s kubelet, node01 Created container mysql
Normal Started 57s kubelet, node01 Started container mysql
资源注解annotations;仅用于为对象提供元数据
[root@master ~]# kubectl explain pods.metadata
KIND: Pod
VERSION: v1
RESOURCE: metadata <Object>
DESCRIPTION:
Standard object‘s metadata. More info:
https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
ObjectMeta is metadata that all persisted resources must have, which
includes all objects users must create.
FIELDS:
annotations <map[string]string> 资源注解
Annotations is an unstructured key value map stored with a resource that
may be set by external tools to store and retrieve arbitrary metadata. They
are not queryable and should be preserved when modifying objects. More
info: http://kubernetes.io/docs/user-guide/annotations
clusterName <string>
The name of the cluster which the object belongs to. This is used to
distinguish resources with same name and namespace in different clusters.
This field is not set anywhere right now and apiserver is going to ignore
it if set in create or update request.
creationTimestamp <string>
CreationTimestamp is a timestamp representing the server time when this
object was created. It is not guaranteed to be set in happens-before order
across separate operations. Clients may not set this value. It is
represented in RFC3339 form and is in UTC. Populated by the system.
Read-only. Null for lists. More info:
https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
deletionGracePeriodSeconds <integer>
Number of seconds allowed for this object to gracefully terminate before it
will be removed from the system. Only set when deletionTimestamp is also
set. May only be shortened. Read-only.
deletionTimestamp <string>
DeletionTimestamp is RFC 3339 date and time at which this resource will be
deleted. This field is set by the server when a graceful deletion is
requested by the user, and is not directly settable by a client. The
resource is expected to be deleted (no longer visible from resource lists,
and not reachable by name) after the time in this field, once the
finalizers list is empty. As long as the finalizers list contains items,
deletion is blocked. Once the deletionTimestamp is set, this value may not
be unset or be set further into the future, although it may be shortened or
the resource may be deleted prior to this time. For example, a user may
request that a pod is deleted in 30 seconds. The Kubelet will react by
sending a graceful termination signal to the containers in the pod. After
that 30 seconds, the Kubelet will send a hard termination signal (SIGKILL)
to the container and after cleanup, remove the pod from the API. In the
presence of network partitions, this object may still exist after this
timestamp, until an administrator or automated process can determine the
resource is fully terminated. If not set, graceful deletion of the object
has not been requested. Populated by the system when a graceful deletion is
requested. Read-only. More info:
https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
finalizers <[]string>
Must be empty before the object is deleted from the registry. Each entry is
an identifier for the responsible component that will remove the entry from
the list. If the deletionTimestamp of the object is non-nil, entries in
this list can only be removed. Finalizers may be processed and removed in
any order. Order is NOT enforced because it introduces significant risk of
stuck finalizers. finalizers is a shared field, any actor with permission
can reorder it. If the finalizer list is processed in order, then this can
lead to a situation in which the component responsible for the first
finalizer in the list is waiting for a signal (field value, external
system, or other) produced by a component responsible for a finalizer later
in the list, resulting in a deadlock. Without enforced ordering finalizers
are free to order amongst themselves and are not vulnerable to ordering
changes in the list.
generateName <string>
GenerateName is an optional prefix, used by the server, to generate a
unique name ONLY IF the Name field has not been provided. If this field is
used, the name returned to the client will be different than the name
passed. This value will also be combined with a unique suffix. The provided
value has the same validation rules as the Name field, and may be truncated
by the length of the suffix required to make the value unique on the
server. If this field is specified and the generated name exists, the
server will NOT return a 409 - instead, it will either return 201 Created
or 500 with Reason ServerTimeout indicating a unique name could not be
found in the time allotted, and the client should retry (optionally after
the time indicated in the Retry-After header). Applied only if Name is not
specified. More info:
https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#idempotency
generation <integer>
A sequence number representing a specific generation of the desired state.
Populated by the system. Read-only.
labels <map[string]string>
Map of string keys and values that can be used to organize and categorize
(scope and select) objects. May match selectors of replication controllers
and services. More info: http://kubernetes.io/docs/user-guide/labels
managedFields <[]Object>
ManagedFields maps workflow-id and version to the set of fields that are
managed by that workflow. This is mostly for internal housekeeping, and
users typically shouldn‘t need to set or understand this field. A workflow
can be the user‘s name, a controller‘s name, or the name of a specific
apply path like "ci-cd". The set of fields is always in the version that
the workflow used when modifying the object.
name <string>
Name must be unique within a namespace. Is required when creating
resources, although some resources may allow a client to request the
generation of an appropriate name automatically. Name is primarily intended
for creation idempotence and configuration definition. Cannot be updated.
More info: http://kubernetes.io/docs/user-guide/identifiers#names
namespace <string>
Namespace defines the space within each name must be unique. An empty
namespace is equivalent to the "default" namespace, but "default" is the
canonical representation. Not all objects are required to be scoped to a
namespace - the value of this field for those objects will be empty. Must
be a DNS_LABEL. Cannot be updated. More info:
http://kubernetes.io/docs/user-guide/namespaces
ownerReferences <[]Object>
List of objects depended by this object. If ALL objects in the list have
been deleted, this object will be garbage collected. If this object is
managed by a controller, then an entry in this list will point to this
controller, with the controller field set to true. There cannot be more
than one managing controller.
resourceVersion <string>
An opaque value that represents the internal version of this object that
can be used by clients to determine when objects have changed. May be used
for optimistic concurrency, change detection, and the watch operation on a
resource or set of resources. Clients must treat these values as opaque and
passed unmodified back to the server. They may only be valid for a
particular resource or set of resources. Populated by the system.
Read-only. Value must be treated as opaque by clients and . 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 1.2
release and the field is planned to be removed in 1.21 release.
uid <string>
UID is the unique in time and space value for this object. It is typically
generated by the server on successful creation of a resource and is not
allowed to change on PUT operations. Populated by the system. Read-only.
More info: http://kubernetes.io/docs/user-guide/identifiers#uids
pod 的生命周期状态
Pending:调度不成功；一般调度条件不满足，pod挂起 Running:处于运行状态 Failed：失败 Succeeded:成功 Unknown：未知状态
pod 创建流程经历那些阶段
请求提交给apisaerver -->apiserver先把它保存在etcd当中--->aipserver会请求Schedule负责调度如果调度成功并把调度结果存放etcd当中---->目标节点的kubelet，通过maseter上的apiserver就会知道有一个新任务给自己---kubelet就会拿到用户期望创建pod的清单，并跟根据清单运行起pod，无论创建成功或失败都会把状态发送给apiserver
pod里容器探测
liveness：容器是否存活，因为pod可以有多个容器，一个容器挂了，另一个容器没挂，pod正常
readiness：容器里的服务是否可以正常提供服务
pod里容器重启策略
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