kubectl&&YAML,深入理解pod对象(下)
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查看api的版本
[root@k8s-master src]# kubectl api-versions
admissionregistration.k8s.io/v1
admissionregistration.k8s.io/v1beta1
apiextensions.k8s.io/v1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1
apiregistration.k8s.io/v1beta1
apps/v1
authentication.k8s.io/v1
authentication.k8s.io/v1beta1
authorization.k8s.io/v1
authorization.k8s.io/v1beta1
autoscaling/v1
autoscaling/v2beta1
autoscaling/v2beta2
batch/v1
batch/v1beta1
certificates.k8s.io/v1beta1
coordination.k8s.io/v1
coordination.k8s.io/v1beta1
events.k8s.io/v1beta1
extensions/v1beta1
networking.k8s.io/v1
networking.k8s.io/v1beta1
node.k8s.io/v1beta1
policy/v1beta1
rbac.authorization.k8s.io/v1
rbac.authorization.k8s.io/v1beta1
scheduling.k8s.io/v1
scheduling.k8s.io/v1beta1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1
[root@k8s-master src]# kubectl --help
kubectl controls the Kubernetes cluster manager.
Find more information at:
https://kubernetes.io/docs/reference/kubectl/overview/
Basic Commands (Beginner):
create Create a resource from a file or from stdin.
expose Take a replication controller, service, deployment or pod and
expose it as a new Kubernetes Service
run Run a particular image on the cluster
set Set specific features on objects
Basic Commands (Intermediate):
explain Documentation of resources
get Display one or many resources
edit Edit a resource on the server
delete Delete resources by filenames, stdin, resources and names, or
by resources and label selector
Deploy Commands:
rollout Manage the rollout of a resource
scale Set a new size for a Deployment, ReplicaSet, Replication
Controller, or Job
autoscale Auto-scale a Deployment, ReplicaSet, or ReplicationController
Cluster Management Commands:
certificate Modify certificate resources.
cluster-info Display cluster info
top Display Resource (CPU/Memory/Storage) usage.
cordon Mark node as unschedulable
uncordon Mark node as schedulable
drain Drain node in preparation for maintenance
taint Update the taints on one or more nodes
Troubleshooting and Debugging Commands:
describe Show details of a specific resource or group of resources
logs Print the logs for a container in a pod
attach Attach to a running container
exec Execute a command in a container
port-forward Forward one or more local ports to a pod
proxy Run a proxy to the Kubernetes API server
cp Copy files and directories to and from containers.
auth Inspect authorization
Advanced Commands:
diff Diff live version against would-be applied version
apply Apply a configuration to a resource by filename or stdin
patch Update field(s) of a resource using strategic merge patch
replace Replace a resource by filename or stdin
wait Experimental: Wait for a specific condition on one or many
resources.
convert Convert config files between different API versions
kustomize Build a kustomization target from a directory or a remote url.
Settings Commands:
label Update the labels on a resource
annotate Update the annotations on a resource
completion Output shell completion code for the specified shell (bash or
zsh)
Other Commands:
api-resources Print the supported API resources on the server
api-versions Print the supported API versions on the server, in the form of
"group/version"
config Modify kubeconfig files
plugin Provides utilities for interacting with plugins.
version Print the client and server version information
Usage:
kubectl [flags] [options]
Use "kubectl
Use "kubectl options" for a list of global command-line options (applies to all
commands).
用run命令生成yaml文件：
[root@k8s-master src]# kubectl create deployment web --image=nginx -o yaml --dry-run > deployment.yaml
[root@k8s-master src]# vim deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: web
name: web
spec:
replicas: 1
selector:
matchLabels:
app: web
strategy: {}
template:
metadata:
labels:
app: web
spec:
containers:
- image: nginx
name: nginx
resources: {}
用get命令导出yaml文件
[root@k8s-master src]# kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
nginx 1/1 1 1 10h
web 0/1 1 0 5m41s
web2 1/1 1 1 7h25m
[root@k8s-master src]# kubectl get deploy web
NAME READY UP-TO-DATE AVAILABLE AGE
web 0/1 1 0 5m51s
[root@k8s-master src]# kubectl get deploy web -o yaml
apiVersion: apps/v1
kind: Deployment
metadata:
annotations:
deployment.kubernetes.io/revision: "1"
creationTimestamp: "2020-02-12T12:55:39Z"
generation: 1
labels:
app: web
name: web
namespace: default
resourceVersion: "56329"
selfLink: /apis/apps/v1/namespaces/default/deployments/web
uid: 74f83717-d28b-404e-a8a2-ed6a6bb601b6
spec:
progressDeadlineSeconds: 600
replicas: 1
revisionHistoryLimit: 10
selector:
matchLabels:
app: web
strategy:
rollingUpdate:
maxSurge: 25%
maxUnavailable: 25%
type: RollingUpdate
template:
metadata:
creationTimestamp: null
labels:
app: web
spec:
containers:
- image: nginx
imagePullPolicy: Always
name: nginx
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
DNSPolicy: ClusterFirst
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
terminationGracePeriodSeconds: 30
status:
conditions:
- lastTransitionTime: "2020-02-12T12:55:39Z"
lastUpdateTime: "2020-02-12T12:55:39Z"
message: Deployment does not have minimum availability.
reason: MinimumReplicasUnavailable
status: "False"
type: Available
- lastTransitionTime: "2020-02-12T12:55:39Z"
lastUpdateTime: "2020-02-12T12:55:39Z"
message: ReplicaSet "web-d86c95cc9" is progressing.
reason: ReplicaSetUpdated
status: "True"
type: Progressing
observedGeneration: 1
replicas: 1
unavailableReplicas: 1
updatedReplicas: 1
[root@k8s-master src]# kubectl get deploy web -o yaml --export > deployment2.yaml
Flag --export has been deprecated, This flag is deprecated and will be removed in future.
注释掉的可以去掉
[root@k8s-master src]# cat deployment2.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
# annotations:
# deployment.kubernetes.io/revision: "1"
# creationTimestamp: null
# generation: 1
labels:
app: web
name: web
# selfLink: /apis/apps/v1/namespaces/default/deployments/web
spec:
# progressDeadlineSeconds: 600
replicas: 1
# revisionHistoryLimit: 10
selector:
matchLabels:
app: web
strategy:
rollingUpdate:
maxSurge: 25%
maxUnavailable: 25%
type: RollingUpdate
template:
metadata:
# creationTimestamp: null
labels:
app: web
spec:
containers:
- image: nginx
imagePullPolicy: Always
name: nginx
resources: {}
# terminationMessagePath: /dev/termination-log
# terminationMessagePolicy: File
# dnsPolicy: ClusterFirst
restartPolicy: Always
# schedulerName: default-scheduler
# securityContext: {}
# terminationGracePeriodSeconds: 30
#status: {}
过滤后得出以下文本：
[root@k8s-master src]# grep -Ev "^#" deployment2.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: web
name: web
spec:
replicas: 1
selector:
matchLabels:
app: web
strategy:
rollingUpdate:
maxSurge: 25%
maxUnavailable: 25%
type: RollingUpdate
template:
metadata:
labels:
app: web
spec:
containers:
- image: nginx
imagePullPolicy: Always
name: nginx
resources: {}
restartPolicy: Always
[root@k8s-master src]# kubectl explain pods
KIND: Pod
VERSION: v1
DESCRIPTION:
Pod is a collection of containers that can run on a host. This resource is
created by clients and scheduled onto hosts.
FIELDS:
apiVersion
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
kind
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
metadata
Standard object's metadata. More info:
https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
spec
Specification of the desired behavior of the pod. More info:
https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
status
Most recently observed status of the pod. This data may not be up to date.
Populated by the system. Read-only. More info:
https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
[root@k8s-master src]# kubectl explain pods.spec.containers
KIND: Pod
VERSION: v1
RESOURCE: containers <[]Object>
DESCRIPTION:
List of containers belonging to the pod. Containers cannot currently be
added or removed. There must be at least one container in a Pod. Cannot be
updated.
A single application container that you want to run within a pod.
FIELDS:
args <[]string>
Arguments to the entrypoint. The docker image's CMD is used if this is not
provided. Variable references $(VAR_NAME) are expanded using the
container's environment. If a variable cannot be resolved, the reference in
the input string will be unchanged. The $(VAR_NAME) syntax can be escaped
with a double $$, ie: $$(VAR_NAME). Escaped references will never be
expanded, regardless of whether the variable exists or not. Cannot be
updated. More info:
https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/#running-a-command-in-a-shell
command <[]string>
Entrypoint array. Not executed within a shell. The docker image's
ENTRYPOINT is used if this is not provided. Variable references $(VAR_NAME)
are expanded using the container's environment. If a variable cannot be
resolved, the reference in the input string will be unchanged. The
$(VAR_NAME) syntax can be escaped with a double $$, ie: $$(VAR_NAME).
Escaped references will never be expanded, regardless of whether the
variable exists or not. Cannot be updated. More info:
https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/#running-a-command-in-a-shell
env <[]Object>
List of environment variables to set in the container. Cannot be updated.
envFrom <[]Object>
List of sources to populate environment variables in the container. The
keys defined within a source must be a C_IDENTIFIER. All invalid keys will
be reported as an event when the container is starting. When a key exists
in multiple sources, the value associated with the last source will take
precedence. Values defined by an Env with a duplicate key will take
precedence. Cannot be updated.
image
Docker image name. More info:
https://kubernetes.io/docs/concepts/containers/images This field is
optional to allow higher level config management to default or override
container images in workload controllers like Deployments and StatefulSets.
imagePullPolicy
Image pull policy. One of Always, Never, IfNotPresent. Defaults to Always
if :latest tag is specified, or IfNotPresent otherwise. Cannot be updated.
More info:
https://kubernetes.io/docs/concepts/containers/images#updating-images
lifecycle
Actions that the management system should take in response to container
lifecycle events. Cannot be updated.
livenessProbe
Periodic probe of container liveness. Container will be restarted if the
probe fails. Cannot be updated. More info:
https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle#container-probes
name
Name of the container specified as a DNS_LABEL. Each container in a pod
must have a unique name (DNS_LABEL). Cannot be updated.
ports <[]Object>
List of ports to expose from the container. Exposing a port here gives the
system additional information about the network connections a container
uses, but is primarily informational. Not specifying a port here DOES NOT
prevent that port from being exposed. Any port which is listening on the
default "0.0.0.0" address inside a container will be accessible from the
network. Cannot be updated.
readinessProbe
Periodic probe of container service readiness. Container will be removed
from service endpoints if the probe fails. Cannot be updated. More info:
https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle#container-probes
resources
Compute Resources required by this container. Cannot be updated. More info:
https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/
securityContext
Security options the pod should run with. More info:
https://kubernetes.io/docs/concepts/policy/security-context/ More info:
https://kubernetes.io/docs/tasks/configure-pod-container/security-context/
startupProbe
StartupProbe indicates that the Pod has successfully initialized. If
specified, no other probes are executed until this completes successfully.
If this probe fails, the Pod will be restarted, just as if the
livenessProbe failed. This can be used to provide different probe
parameters at the beginning of a Pod's lifecycle, when it might take a long
time to load data or warm a cache, than during steady-state operation. This
cannot be updated. This is an alpha feature enabled by the StartupProbe
feature flag. More info:
https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle#container-probes
stdin
Whether this container should allocate a buffer for stdin in the container
runtime. If this is not set, reads from stdin in the container will always
result in EOF. Default is false.
stdinOnce
Whether the container runtime should close the stdin channel after it has
been opened by a single attach. When stdin is true the stdin stream will
remain open across multiple attach sessions. If stdinOnce is set to true,
stdin is opened on container start, is empty until the first client
attaches to stdin, and then remains open and accepts data until the client
disconnects, at which time stdin is closed and remains closed until the
container is restarted. If this flag is false, a container processes that
reads from stdin will never receive an EOF. Default is false
terminationMessagePath
Optional: Path at which the file to which the container's termination
message will be written is mounted into the container's filesystem. Message
written is intended to be brief final status, such as an assertion failure
message. Will be truncated by the node if greater than 4096 bytes. The
total message length across all containers will be limited to 12kb.
Defaults to /dev/termination-log. Cannot be updated.
terminationMessagePolicy
Indicate how the termination message should be populated. File will use the
contents of terminationMessagePath to populate the container status message
on both success and failure. FallbackToLogsOnError will use the last chunk
of container log output if the termination message file is empty and the
container exited with an error. The log output is limited to 2048 bytes or
80 lines, whichever is smaller. Defaults to File. Cannot be updated.
tty
Whether this container should allocate a TTY for itself, also requires
'stdin' to be true. Default is false.
volumeDevices <[]Object>
volumeDevices is the list of block devices to be used by the container.
This is a beta feature.
volumeMounts <[]Object>
Pod volumes to mount into the container's filesystem. Cannot be updated.
workingDir
Container's working directory. If not specified, the container runtime's
default will be used, which might be configured in the container image.
Cannot be updated.
1:15:00
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