输出kubectl与apiserver交互的报文内容

写在前面

日常访问kubernetes是离不开kubectl的，我们平时开发的时候基本都是走的apiserver的rest api，常常需要访问官网的api-reference，十分得不如kubectl用着方便啊，但是没办法。。。
然后就总是想着能不能kubectl执行命令的时候，把发到后端的报文打印出来，这样就不用一遍一遍的翻官方文档了，没想到，kubectl早就洞察了一切啊，一查还真有打印选项。

正文

 kubectl get deployment --v=8
I0702 16:33:03.774716   19207 loader.go:359] Config loaded from file /root/.kube/config
I0702 16:33:03.797326   19207 round_trippers.go:416] GET https://172.18.141.129:6443/apis/extensions/v1beta1/namespaces/default/deployments?limit=500
I0702 16:33:03.797382   19207 round_trippers.go:423] Request Headers:
I0702 16:33:03.797407   19207 round_trippers.go:426]     Accept: application/json;as=Table;v=v1beta1;g=meta.k8s.io, application/json
I0702 16:33:03.797428   19207 round_trippers.go:426]     User-Agent: kubectl/v1.14.0 (linux/amd64) kubernetes/641856d
I0702 16:33:03.825980   19207 round_trippers.go:441] Response Status: 200 OK in 28 milliseconds
I0702 16:33:03.826016   19207 round_trippers.go:444] Response Headers:
I0702 16:33:03.826031   19207 round_trippers.go:447]     Content-Type: application/json
I0702 16:33:03.826045   19207 round_trippers.go:447]     Date: Tue, 02 Jul 2019 08:33:03 GMT
I0702 16:33:03.826301   19207 request.go:942] Response Body: {"kind":"Table","apiVersion":"meta.k8s.io/v1beta1","metadata":{"selfLink":"/apis/extensions/v1beta1/namespaces/default/deployments","resourceVersion":"5553091"},"columnDefinitions":[{"name":"Name","type":"string","format":"name","description":"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","priority":0},{"name":"Ready","type":"string","format":"","description":"Number of the pod with ready state","priority":0},{"name":"Up-to-date","type":"string","format":"","description":"Total number of non-terminated pods targeted by this deployment that have the desired template spec.","priority":0},{"name":"Available","type":"string","format":"","description":"Total number of available pods (ready for at least minReadySec [truncated 5739 chars]
I0702 16:33:03.828649   19207 get.go:570] no kind is registered for the type v1beta1.Table in scheme "k8s.io/kubernetes/pkg/api/legacyscheme/scheme.go:29"

如上，只需在原有的kubectl命令后面加一个--v=8，就可以看到所有的交互信息了，request，response一目了然。

使用 -v 或 --v 来指定日志级别：