• kubectl命令导引

[root@xtwj89 ~]# kubectl
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 Servicerun           Run a particular image on the clusterset           Set specific features on objectsBasic Commands (Intermediate):explain       Documentation of resourcesget           Display one or many resourcesedit          Edit a resource on the serverdelete        Delete resources by filenames, stdin, resources and names, or by resources and label selectorDeploy Commands:rollout       Manage the rollout of a resourcescale         Set a new size for a Deployment, ReplicaSet or Replication Controllerautoscale     Auto-scale a Deployment, ReplicaSet, or ReplicationControllerCluster Management Commands:certificate   Modify certificate resources.cluster-info  Display cluster infotop           Display Resource (CPU/Memory/Storage) usage.cordon        Mark node as unschedulableuncordon      Mark node as schedulabledrain         Drain node in preparation for maintenancetaint         Update the taints on one or more nodesTroubleshooting and Debugging Commands:describe      Show details of a specific resource or group of resourceslogs          Print the logs for a container in a podattach        Attach to a running containerexec          Execute a command in a containerport-forward  Forward one or more local ports to a podproxy         Run a proxy to the Kubernetes API servercp            Copy files and directories to and from containers.auth          Inspect authorizationAdvanced Commands:diff          Diff live version against would-be applied versionapply         Apply a configuration to a resource by filename or stdinpatch         Update field(s) of a resource using strategic merge patchreplace       Replace a resource by filename or stdinwait          Experimental: Wait for a specific condition on one or many resources.convert       Convert config files between different API versionskustomize     Build a kustomization target from a directory or a remote url.Settings Commands:label         Update the labels on a resourceannotate      Update the annotations on a resourcecompletion    Output shell completion code for the specified shell (bash or zsh)Other Commands:alpha         Commands for features in alphaapi-resources Print the supported API resources on the serverapi-versions  Print the supported API versions on the server, in the form of "group/version"config        Modify kubeconfig filesplugin        Provides utilities for interacting with plugins.version       Print the client and server version informationUsage:kubectl [flags] [options]Use "kubectl <command> --help" for more information about a given command.
Use "kubectl options" for a list of global command-line options (applies to all commands).
[root@xtwj89 ~]# 

• kubectl 选项

kubectl命令有哪些选项可以供我们在日常管理中使用呢？上面的内容中已经提到了，我们可以通过命令kubectl options来获取。

[root@xtwj89 ~]# kubectl options 
The following options can be passed to any command:--add-dir-header=false: If true, adds the file directory to the header--alsologtostderr=false: log to standard error as well as files--as='': Username to impersonate for the operation--as-group=[]: Group to impersonate for the operation, this flag can be repeated to specify multiple groups.--cache-dir='/root/.kube/http-cache': Default HTTP cache directory--certificate-authority='': Path to a cert file for the certificate authority--client-certificate='': Path to a client certificate file for TLS--client-key='': Path to a client key file for TLS--cluster='': The name of the kubeconfig cluster to use--context='': The name of the kubeconfig context to use--insecure-skip-tls-verify=false: If true, the server's certificate will not be checked for validity. This will
make your HTTPS connections insecure--kubeconfig='': Path to the kubeconfig file to use for CLI requests.--log-backtrace-at=:0: when logging hits line file:N, emit a stack trace--log-dir='': If non-empty, write log files in this directory--log-file='': If non-empty, use this log file--log-file-max-size=1800: Defines the maximum size a log file can grow to. Unit is megabytes. If the value is 0,
the maximum file size is unlimited.--log-flush-frequency=5s: Maximum number of seconds between log flushes--logtostderr=true: log to standard error instead of files--match-server-version=false: Require server version to match client version-n, --namespace='': If present, the namespace scope for this CLI request--password='': Password for basic authentication to the API server--profile='none': Name of profile to capture. One of (none|cpu|heap|goroutine|threadcreate|block|mutex)--profile-output='profile.pprof': Name of the file to write the profile to--request-timeout='0': The length of time to wait before giving up on a single server request. Non-zero values
should contain a corresponding time unit (e.g. 1s, 2m, 3h). A value of zero means don't timeout requests.-s, --server='': The address and port of the Kubernetes API server--skip-headers=false: If true, avoid header prefixes in the log messages--skip-log-headers=false: If true, avoid headers when opening log files--stderrthreshold=2: logs at or above this threshold go to stderr--tls-server-name='': Server name to use for server certificate validation. If it is not provided, the hostname
used to contact the server is used--token='': Bearer token for authentication to the API server--user='': The name of the kubeconfig user to use--username='': Username for basic authentication to the API server-v, --v=0: number for the log level verbosity--vmodule=: comma-separated list of pattern=N settings for file-filtered logging
[root@xtwj89 ~]# 

• kubectl get 用法

[root@xtwj89 ~]# kubectl get --help
Display one or many resourcesPrints a table of the most important information about the specified resources. You can filter the list using a label
selector and the --selector flag. If the desired resource type is namespaced you will only see results in your current
namespace unless you pass --all-namespaces.Uninitialized objects are not shown unless --include-uninitialized is passed.By specifying the output as 'template' and providing a Go template as the value of the --template flag, you can filter
the attributes of the fetched resources.Use "kubectl api-resources" for a complete list of supported resources.Examples:# List all pods in ps output format.kubectl get pods# List all pods in ps output format with more information (such as node name).kubectl get pods -o wide# List a single replication controller with specified NAME in ps output format.kubectl get replicationcontroller web# List deployments in JSON output format, in the "v1" version of the "apps" API group:kubectl get deployments.v1.apps -o json# List a single pod in JSON output format.kubectl get -o json pod web-pod-13je7# List a pod identified by type and name specified in "pod.yaml" in JSON output format.kubectl get -f pod.yaml -o json# List resources from a directory with kustomization.yaml - e.g. dir/kustomization.yaml.kubectl get -k dir/# Return only the phase value of the specified pod.kubectl get -o template pod/web-pod-13je7 --template={{.status.phase}}# List resource information in custom columns.kubectl get pod test-pod -o custom-columns=CONTAINER:.spec.containers[0].name,IMAGE:.spec.containers[0].image# List all replication controllers and services together in ps output format.kubectl get rc,services# List one or more resources by their type and names.kubectl get rc/web service/frontend pods/web-pod-13je7Options:-A, --all-namespaces=false: If present, list the requested object(s) across all namespaces. Namespace in current
context is ignored even if specified with --namespace.--allow-missing-template-keys=true: If true, ignore any errors in templates when a field or map key is missing in
the template. Only applies to golang and jsonpath output formats.--chunk-size=500: Return large lists in chunks rather than all at once. Pass 0 to disable. This flag is beta and
may change in the future.--field-selector='': Selector (field query) to filter on, supports '=', '==', and '!='.(e.g. --field-selector
key1=value1,key2=value2). The server only supports a limited number of field queries per type.-f, --filename=[]: Filename, directory, or URL to files identifying the resource to get from a server.--ignore-not-found=false: If the requested object does not exist the command will return exit code 0.-k, --kustomize='': Process the kustomization directory. This flag can't be used together with -f or -R.-L, --label-columns=[]: Accepts a comma separated list of labels that are going to be presented as columns. Names are
case-sensitive. You can also use multiple flag options like -L label1 -L label2...--no-headers=false: When using the default or custom-column output format, don't print headers (default print
headers).-o, --output='': Output format. One of:
json|yaml|wide|name|custom-columns=...|custom-columns-file=...|go-template=...|go-template-file=...|jsonpath=...|jsonpath-file=...
See custom columns [http://kubernetes.io/docs/user-guide/kubectl-overview/#custom-columns], golang template
[http://golang.org/pkg/text/template/#pkg-overview] and jsonpath template
[http://kubernetes.io/docs/user-guide/jsonpath].--output-watch-events=false: Output watch event objects when --watch or --watch-only is used. Existing objects are
output as initial ADDED events.--raw='': Raw URI to request from the server.  Uses the transport specified by the kubeconfig file.-R, --recursive=false: Process the directory used in -f, --filename recursively. Useful when you want to manage
related manifests organized within the same directory.-l, --selector='': Selector (label query) to filter on, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2)--server-print=true: If true, have the server return the appropriate table output. Supports extension APIs and
CRDs.--show-kind=false: If present, list the resource type for the requested object(s).--show-labels=false: When printing, show all labels as the last column (default hide labels column)--sort-by='': If non-empty, sort list types using this field specification.  The field specification is expressed
as a JSONPath expression (e.g. '{.metadata.name}'). The field in the API resource specified by this JSONPath expression
must be an integer or a string.--template='': Template string or path to template file to use when -o=go-template, -o=go-template-file. The
template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].-w, --watch=false: After listing/getting the requested object, watch for changes. Uninitialized objects are excluded
if no object name is provided.--watch-only=false: Watch for changes to the requested object(s), without listing/getting first.Usage:kubectl get
[(-o|--output=)json|yaml|wide|custom-columns=...|custom-columns-file=...|go-template=...|go-template-file=...|jsonpath=...|jsonpath-file=...]
(TYPE[.VERSION][.GROUP] [NAME | -l label] | TYPE[.VERSION][.GROUP]/NAME ...) [flags] [options]Use "kubectl options" for a list of global command-line options (applies to all commands).
[root@xtwj89 ~]#

那么都有哪些资源可以被查看呢？我们注意到第98行提到可以通过kubectl api-resources命令获取到可以被查看的资源列表，我们不妨试一下。

[root@xtwj89 ~]# kubectl api-resources
NAME                              SHORTNAMES   APIGROUP                       NAMESPACED   KIND
bindings                                                                      true         Binding
componentstatuses                 cs                                          false        ComponentStatus
configmaps                        cm                                          true         ConfigMap
endpoints                         ep                                          true         Endpoints
events                            ev                                          true         Event
limitranges                       limits                                      true         LimitRange
namespaces                        ns                                          false        Namespace
nodes                             no                                          false        Node
persistentvolumeclaims            pvc                                         true         PersistentVolumeClaim
persistentvolumes                 pv                                          false        PersistentVolume
pods                              po                                          true         Pod
podtemplates                                                                  true         PodTemplate
replicationcontrollers            rc                                          true         ReplicationController
resourcequotas                    quota                                       true         ResourceQuota
secrets                                                                       true         Secret
serviceaccounts                   sa                                          true         ServiceAccount
services                          svc                                         true         Service
mutatingwebhookconfigurations                  admissionregistration.k8s.io   false        MutatingWebhookConfiguration
validatingwebhookconfigurations                admissionregistration.k8s.io   false        ValidatingWebhookConfiguration
customresourcedefinitions         crd,crds     apiextensions.k8s.io           false        CustomResourceDefinition
apiservices                                    apiregistration.k8s.io         false        APIService
controllerrevisions                            apps                           true         ControllerRevision
daemonsets                        ds           apps                           true         DaemonSet
deployments                       deploy       apps                           true         Deployment
replicasets                       rs           apps                           true         ReplicaSet
statefulsets                      sts          apps                           true         StatefulSet
tokenreviews                                   authentication.k8s.io          false        TokenReview
localsubjectaccessreviews                      authorization.k8s.io           true         LocalSubjectAccessReview
selfsubjectaccessreviews                       authorization.k8s.io           false        SelfSubjectAccessReview
selfsubjectrulesreviews                        authorization.k8s.io           false        SelfSubjectRulesReview
subjectaccessreviews                           authorization.k8s.io           false        SubjectAccessReview
horizontalpodautoscalers          hpa          autoscaling                    true         HorizontalPodAutoscaler
cronjobs                          cj           batch                          true         CronJob
jobs                                           batch                          true         Job
certificatesigningrequests        csr          certificates.k8s.io            false        CertificateSigningRequest
leases                                         coordination.k8s.io            true         Lease
endpointslices                                 discovery.k8s.io               true         EndpointSlice
events                            ev           events.k8s.io                  true         Event
ingresses                         ing          extensions                     true         Ingress
ingressclasses                                 networking.k8s.io              false        IngressClass
ingresses                         ing          networking.k8s.io              true         Ingress
networkpolicies                   netpol       networking.k8s.io              true         NetworkPolicy
runtimeclasses                                 node.k8s.io                    false        RuntimeClass
poddisruptionbudgets              pdb          policy                         true         PodDisruptionBudget
podsecuritypolicies               psp          policy                         false        PodSecurityPolicy
clusterrolebindings                            rbac.authorization.k8s.io      false        ClusterRoleBinding
clusterroles                                   rbac.authorization.k8s.io      false        ClusterRole
rolebindings                                   rbac.authorization.k8s.io      true         RoleBinding
roles                                          rbac.authorization.k8s.io      true         Role
priorityclasses                   pc           scheduling.k8s.io              false        PriorityClass
csidrivers                                     storage.k8s.io                 false        CSIDriver
csinodes                                       storage.k8s.io                 false        CSINode
storageclasses                    sc           storage.k8s.io                 false        StorageClass
volumeattachments                              storage.k8s.io                 false        VolumeAttachment
[root@xtwj89 ~]#