[cloud native learning notes] learn about kubernetes configuration list yaml file

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Preface

Mentioned earlier When the application is deployed , In practical work, we use kubectl apply. This section describes the specific usage of these two commands , And the preparation of the configuration used with it .

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One 、kubectl apply -f

-f yes kubectl apply The most common command options . Enter... By filename or console , Allocate resources . Accept JSON and YAML Format description file .YAML Format is more recommended .

-f, --filename=[]: File name containing configuration information , Directory name or URL.

Example ：

#  take pod.json The configuration in applies to pod
$ kubectl apply -f ./kube-config.yaml

#  Input to the console JSON Configuration is applied to Pod
$ cat kube-config.yaml | kubectl apply -f -

Two 、k8s yaml The configuration file

About yaml I won't give you a specific introduction , The file suffix is usually .yaml perhaps .yml The syntax is as follows ：

Case sensitive
Use indentation to indicate hierarchy
Indenting is not allowed tab, Only spaces are allowed
The number of indented spaces doesn't matter , Just align the elements at the same level to the left
'#' Notation

stay k8s In the configuration manifest file of , Need to master yaml Key value pairs and arrays in syntax . recommend yaml Introduction learning .

k8s Of yaml The configuration is mainly divided into four parts :

• apiVersion
• kind
• metadata
• spec

Such as pod resources yaml Example ：

apiVersion: v1 # API Version number , Must be in `kubectl apiversion` in 
kind: Pod  #  Specify the type of resource to create , The resource type can be Deployment、Service etc. , According to the actual situation . 
metadata:  #  Metadata , Include some meta Information , Such as the name 、namespace、 Labels and other information .
  name: nginx-test #  The name of the resource , In the same namespace Must be unique in space 
spec: #  Resource specifications , Including some container,storage,volume And other things k8s Required parameters .
  containers: #  List of containers 
    - name: front-end #  Container name 
      image: nginx #  Container mirror 
      ports:
        - containerPort: 80 #  The external port of the container 

1. apiVersion

To designate api Version number , It usually says v1, But it's not dead , It can be executed kubectl api-versions Command view , One of the .

$ kubectl api-versions
admissionregistration.k8s.io/v1
apiextensions.k8s.io/v1
apiregistration.k8s.io/v1
apps/v1
authentication.k8s.io/v1
authorization.k8s.io/v1
autoscaling/v1
autoscaling/v2
autoscaling/v2beta1
autoscaling/v2beta2
batch/v1
batch/v1beta1
certificates.k8s.io/v1
coordination.k8s.io/v1
discovery.k8s.io/v1
discovery.k8s.io/v1beta1
events.k8s.io/v1
events.k8s.io/v1beta1
flowcontrol.apiserver.k8s.io/v1beta1
flowcontrol.apiserver.k8s.io/v1beta2
networking.k8s.io/v1
node.k8s.io/v1
node.k8s.io/v1beta1
policy/v1
policy/v1beta1
rbac.authorization.k8s.io/v1
scheduling.k8s.io/v1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1

2. kind

It means that we should yaml Defined resource type ,k8s There are many kinds of resources in , Can execute orders kubectl api-resources -o wide see , But most of them are not often used . Common resources mainly include Deployment,Services,Job etc. .

$ kubectl api-resources -o wide
NAME                              SHORTNAMES   APIVERSION                             NAMESPACED   KIND                             VERBS
bindings                                       v1                                     true         Binding                          [create]
componentstatuses                 cs           v1                                     false        ComponentStatus                  [get list]
configmaps                        cm           v1                                     true         ConfigMap                        [create delete deletecollection get list patch update watch]
endpoints                         ep           v1                                     true         Endpoints                        [create delete deletecollection get list patch update watch]
events                            ev           v1                                     true         Event                            [create delete deletecollection get list patch update watch]
limitranges                       limits       v1                                     true         LimitRange                       [create delete deletecollection get list patch update watch]
namespaces                        ns           v1                                     false        Namespace                        [create delete get list patch update watch]
nodes                             no           v1                                     false        Node                             [create delete deletecollection get list patch update watch]
persistentvolumeclaims            pvc          v1                                     true         PersistentVolumeClaim            [create delete deletecollection get list patch update watch]
persistentvolumes                 pv           v1                                     false        PersistentVolume                 [create delete deletecollection get list patch update watch]
pods                              po           v1                                     true         Pod                              [create delete deletecollection get list patch update watch]
podtemplates                                   v1                                     true         PodTemplate                      [create delete deletecollection get list patch update watch]
replicationcontrollers            rc           v1                                     true         ReplicationController            [create delete deletecollection get list patch update watch]
resourcequotas                    quota        v1                                     true         ResourceQuota                    [create delete deletecollection get list patch update watch]
secrets                                        v1                                     true         Secret                           [create delete deletecollection get list patch update watch]
serviceaccounts                   sa           v1                                     true         ServiceAccount                   [create delete deletecollection get list patch update watch]
services                          svc          v1                                     true         Service                          [create delete deletecollection get list patch update watch]
mutatingwebhookconfigurations                  admissionregistration.k8s.io/v1        false        MutatingWebhookConfiguration     [create delete deletecollection get list patch update watch]
validatingwebhookconfigurations                admissionregistration.k8s.io/v1        false        ValidatingWebhookConfiguration   [create delete deletecollection get list patch update watch]
customresourcedefinitions         crd,crds     apiextensions.k8s.io/v1                false        CustomResourceDefinition         [create delete deletecollection get list patch update watch]
apiservices                                    apiregistration.k8s.io/v1              false        APIService                       [create delete deletecollection get list patch update watch]
controllerrevisions                            apps/v1                                true         ControllerRevision               [create delete deletecollection get list patch update watch]
daemonsets                        ds           apps/v1                                true         DaemonSet                        [create delete deletecollection get list patch update watch]
deployments                       deploy       apps/v1                                true         Deployment                       [create delete deletecollection get list patch update watch]
replicasets                       rs           apps/v1                                true         ReplicaSet                       [create delete deletecollection get list patch update watch]
statefulsets                      sts          apps/v1                                true         StatefulSet                      [create delete deletecollection get list patch update watch]
tokenreviews                                   authentication.k8s.io/v1               false        TokenReview                      [create]
localsubjectaccessreviews                      authorization.k8s.io/v1                true         LocalSubjectAccessReview         [create]
selfsubjectaccessreviews                       authorization.k8s.io/v1                false        SelfSubjectAccessReview          [create]
selfsubjectrulesreviews                        authorization.k8s.io/v1                false        SelfSubjectRulesReview           [create]
subjectaccessreviews                           authorization.k8s.io/v1                false        SubjectAccessReview              [create]
horizontalpodautoscalers          hpa          autoscaling/v2                         true         HorizontalPodAutoscaler          [create delete deletecollection get list patch update watch]
cronjobs                          cj           batch/v1                               true         CronJob                          [create delete deletecollection get list patch update watch]
jobs                                           batch/v1                               true         Job                              [create delete deletecollection get list patch update watch]
certificatesigningrequests        csr          certificates.k8s.io/v1                 false        CertificateSigningRequest        [create delete deletecollection get list patch update watch]
leases                                         coordination.k8s.io/v1                 true         Lease                            [create delete deletecollection get list patch update watch]
endpointslices                                 discovery.k8s.io/v1                    true         EndpointSlice                    [create delete deletecollection get list patch update watch]
events                            ev           events.k8s.io/v1                       true         Event                            [create delete deletecollection get list patch update watch]
flowschemas                                    flowcontrol.apiserver.k8s.io/v1beta2   false        FlowSchema                       [create delete deletecollection get list patch update watch]
prioritylevelconfigurations                    flowcontrol.apiserver.k8s.io/v1beta2   false        PriorityLevelConfiguration       [create delete deletecollection get list patch update watch]
ingressclasses                                 networking.k8s.io/v1                   false        IngressClass                     [create delete deletecollection get list patch update watch]
ingresses                         ing          networking.k8s.io/v1                   true         Ingress                          [create delete deletecollection get list patch update watch]
networkpolicies                   netpol       networking.k8s.io/v1                   true         NetworkPolicy                    [create delete deletecollection get list patch update watch]
runtimeclasses                                 node.k8s.io/v1                         false        RuntimeClass                     [create delete deletecollection get list patch update watch]
poddisruptionbudgets              pdb          policy/v1                              true         PodDisruptionBudget              [create delete deletecollection get list patch update watch]
podsecuritypolicies               psp          policy/v1beta1                         false        PodSecurityPolicy                [create delete deletecollection get list patch update watch]
clusterrolebindings                            rbac.authorization.k8s.io/v1           false        ClusterRoleBinding               [create delete deletecollection get list patch update watch]
clusterroles                                   rbac.authorization.k8s.io/v1           false        ClusterRole                      [create delete deletecollection get list patch update watch]
rolebindings                                   rbac.authorization.k8s.io/v1           true         RoleBinding                      [create delete deletecollection get list patch update watch]
roles                                          rbac.authorization.k8s.io/v1           true         Role                             [create delete deletecollection get list patch update watch]
priorityclasses                   pc           scheduling.k8s.io/v1                   false        PriorityClass                    [create delete deletecollection get list patch update watch]
csidrivers                                     storage.k8s.io/v1                      false        CSIDriver                        [create delete deletecollection get list patch update watch]
csinodes                                       storage.k8s.io/v1                      false        CSINode                          [create delete deletecollection get list patch update watch]
csistoragecapacities                           storage.k8s.io/v1beta1                 true         CSIStorageCapacity               [create delete deletecollection get list patch update watch]
storageclasses                    sc           storage.k8s.io/v1                      false        StorageClass                     [create delete deletecollection get list patch update watch]
volumeattachments                              storage.k8s.io/v1                      false        VolumeAttachment                 [create delete deletecollection get list patch update watch]

3. metadata

This field is for the resource object " identification ", Metadata , It's also from Kubernetes The main basis for finding this object . Include name 、namespace、 Information such as labels and notes .metadata Common subfields in are ：

• name: Resource name , In the same namespace It has to be the only one .
• namespace: Namespace , An abstract collection of resources and objects , Yes k8s Divide logically , Achieve hierarchical management , There is a certain degree of resource and permission isolation . built-in namespace Yes default,kube-system and kube-public. The default value is default.
• label: Tag data , Can be used in spec Pass through selectors Match , Achieve binding effect .
• annotation: annotation , Some customized auxiliary information .

4. spec

spec It refers to the specification of resource content , That is, the state we expect our resources to achieve , The specifications and contents of various resources are not uniform , such as pod The contents of this article include container,volume,nodeSelector etc. .Deployment It includes replicas、selector、template etc. .

For a more comprehensive introduction to specific fields, please refer to spec Common fields and their meanings

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