K8s之YAML文件
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Kubernetes支持YAML和JSON格式创建资源对象1，JSON格式用于接口之间消息的传递
2，YAML格式用于配置和管理
3，YAML是一种简洁的非标记性语言
语法格式：
缩进标识层级关系
不支持制表符（tab）缩进，使用空格缩进
通常开头缩进两个空格
字符后缩进一个空格，如冒号，逗号等
“---”表示YAML格式，一个文件的开始
“#”表示注释
`查看应用名称`
[root@master1 ~]# kubectl api-versions
admissionregistration.k8s.io/v1beta1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1
apiregistration.k8s.io/v1beta1
apps/v1
apps/v1beta1
apps/v1beta2
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/v1beta1
events.k8s.io/v1beta1
extensions/v1beta1
networking.k8s.io/v1
policy/v1beta1
rbac.authorization.k8s.io/v1
rbac.authorization.k8s.io/v1beta1
scheduling.k8s.io/v1beta1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1
[root@master1 ~]# mkdir demo
[root@master1 ~]# cd demo/
[root@master1 demo]# vim nginx-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: my-nginx
labels:
app: nginx
spec:
replicas: 2
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.15.4
ports:
- containerPort: 80
#插入内容后按Esc退出插入模式，输入:wq保存退出
[root@master1 demo]# kubectl create -f my-nginx.yaml
deployment.apps/my-nginx created
[root@master1 demo]# kubectl get pods
NAME READY STATUS RESTARTS AGE
`my-nginx-d55b94fd-kc2gl 1/1 Running 0 47s`
`my-nginx-d55b94fd-tkr42 1/1 Running 0 47s`
nginx-6c94d899fd-8pf48 1/1 Running 0 23h
nginx-deployment-5477945587-f5dsm 1/1 Running 0 22h
nginx-deployment-5477945587-hmgd2 1/1 Running 0 22h
nginx-deployment-5477945587-pl2hn 1/1 Running 0 22h
[root@master1 demo]# vim my-nginx-service.yaml
apiVersion: v1
kind: Service
metadata:
name: my-nginx-service
labels:
app: nginx
spec:
type: NodePort
ports:
- port: 80
targetPort: 80
selector:
app: nginx
#插入内容后按Esc退出插入模式，输入:wq保存退出
[root@master1 demo]# kubectl create -f my-nginx-service.yaml
service/my-nginx-service created
`查看服务`
[root@master1 demo]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.0.0.1 <none> 443/TCP 8d
`my-nginx-service NodePort 10.0.0.210 <none> 80:40377/TCP 20s`
nginx-service NodePort 10.0.0.242 <none> 80:40422/TCP 33h1.自动测试命令的正确性，并不执行创建：
[root@master1 demo]# kubectl run my-nginx --image=nginx --port=80 --replicas=2 --dry-run
kubectl run --generator=deployment/apps.v1beta1 is DEPRECATED and will be removed in a future version. Use kubectl create instead.
deployment.apps/my-nginx created (dry run)2.查看生成yaml格式：
[root@master1 demo]# kubectl run my-nginx --image=nginx --port=80 --replicas=2 --dry-run -o yaml
kubectl run --generator=deployment/apps.v1beta1 is DEPRECATED and will be removed in a future version. Use kubectl create instead.
apiVersion: apps/v1beta1
kind: Deployment
metadata:
creationTimestamp: null
labels:
run: my-nginx
name: my-nginx
spec:
replicas: 2
selector:
matchLabels:
run: my-nginx
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
run: my-nginx
spec:
containers:
- image: nginx
name: my-nginx
ports:
- containerPort: 80
resources: {}
status: {}3.生成yaml模板文件：
[root@master1 demo]# kubectl run my-nginx --image=nginx --port=80 --replicas=2 --dry-run -o yaml > nginx-deploy.yaml
kubectl run --generator=deployment/apps.v1beta1 is DEPRECATED and will be removed in a future version. Use kubectl create instead.4.导出json格式文件：
[root@master1 demo]# kubectl run my-nginx --image=nginx --port=80 --replicas=2 --dry-run -o json
kubectl run --generator=deployment/apps.v1beta1 is DEPRECATED and will be removed in a future version. Use kubectl create instead.
{
"kind": "Deployment",
"apiVersion": "apps/v1beta1",
"metadata": {
"name": "my-nginx",
"creationTimestamp": null,
"labels": {
"run": "my-nginx"
}
},
"spec": {
"replicas": 2,
"selector": {
"matchLabels": {
"run": "my-nginx"
}
},
"template": {
"metadata": {
"creationTimestamp": null,
"labels": {
"run": "my-nginx"
}
},
"spec": {
"containers": [
{
"name": "my-nginx",
"image": "nginx",
"ports": [
{
"containerPort": 80
}
],
"resources": {}
}
]
}
},
"strategy": {}
},
"status": {}
}5.将现有的资源生成模板导出：
[root@master1 demo]# kubectl get deploy/nginx --export -o yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
annotations:
deployment.kubernetes.io/revision: "2"
creationTimestamp: null
generation: 1
labels:
run: nginx
name: nginx
selfLink: /apis/extensions/v1beta1/namespaces/default/deployments/nginx
spec:
progressDeadlineSeconds: 600
replicas: 1
revisionHistoryLimit: 2
selector:
matchLabels:
run: nginx
strategy:
rollingUpdate:
maxSurge: 25%
maxUnavailable: 25%
type: RollingUpdate
template:
metadata:
creationTimestamp: null
labels:
run: nginx
spec:
containers:
- image: nginx:1.14
imagePullPolicy: Always
name: nginx
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
dnsPolicy: ClusterFirst
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
terminationGracePeriodSeconds: 30
status: {}6.保存到文件中：
[root@master1 demo]# kubectl get deploy/nginx --export -o yaml > my-deploy.yaml7.查看字段帮助信息：
[root@master1 demo]# 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 <string>
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 <string>
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 <Object>
Actions that the management system should take in response to container
lifecycle events. Cannot be updated.
livenessProbe <Object>
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 <string> -required-
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 <Object>
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 <Object>
Compute Resources required by this container. Cannot be updated. More info:
https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/
securityContext <Object>
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/
stdin <boolean>
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 <boolean>
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 <string>
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 <string>
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 <boolean>
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 an alpha feature and may change in the future.
volumeMounts <[]Object>
Pod volumes to mount into the container‘s filesystem. Cannot be updated.
workingDir <string>
Container‘s working directory. If not specified, the container runtime‘s
default will be used, which might be configured in the container image.
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