kubernetes的调试方法
目录
说明
这篇文章会持续更新，主要记录实际使用的一些调试方法。
在代码中找到资源的定义
譬如，在kubernetes的1.6.4版本中调试NetworkPolicy。
定义的NetworkPolicy如下：
$kubectl -n lijiaob-space get networkpolicy -o yaml
apiVersion: v1
items:
- apiVersion: extensions/v1beta1
kind: NetworkPolicy
metadata:
creationTimestamp: 2017-09-11T07:03:02Z
generation: 1
name: isolation-access-rules
namespace: lijiaob-space
resourceVersion: "23537272"
selfLink: /apis/extensions/v1beta1/namespaces/lijiaob-space/networkpolicies/isolation-access-rules
uid: 40c627ff-96bf-11e7-b118-52549da43ad9
spec:
ingress:
- from:
- namespaceSelector:
matchExpressions:
- key: namespace
operator: In
values:
- lijiaob-space
podSelector: {}
kind: List
metadata: {}
现在要在代码中找到NetworkPolicy的定义。
上面显示apiVersion为extensions/v1beta1，所以到pkg/apis/extensions/v1beta1/types.go中寻找NetworkPolicy的定义：
...
type NetworkPolicy struct {
metav1.TypeMeta `json:",inline"`
// Standard object's metadata.
// More info: http://releases.k8s.io/HEAD/docs/devel/api-conventions.md#metadata
// +optional
metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`
// Specification of the desired behavior for this NetworkPolicy.
// +optional
Spec NetworkPolicySpec `json:"spec,omitempty" protobuf:"bytes,2,opt,name=spec"`
}
...
kubernetes 1.6.4中，资源在api和apis目录中定义:
pkg/api:
▾ pkg/
▾ api/
▸ annotations/
▸ endpoints/
▸ errors/
▸ events/
▸ install/
▸ meta/
▸ pod/
▸ resource/
▸ service/
▸ testapi/
▸ testing/
▸ unversioned/
▸ util/
▾ v1/
▸ endpoints/
▸ pod/
▸ service/
▸ validation/
...
pkg/apis:
▾ pkg/
▾ apis/
▸ abac/
▸ apps/
▸ authentication/
▸ authorization/
▸ autoscaling/
▸ batch/
▸ certificates/
▸ componentconfig/
▸ extensions/
▸ imagepolicy/
▸ meta/
▸ policy/
▸ rbac/
▸ settings/
▸ storage/
...
在代码中找到对输入参数的处理
到cmd目录中找到目标子目录，例如kubelet，main函数中调用的AddFlags中完成输入参数的设置。
cmd/kubelet/kubelet.go:
...
s := options.NewKubeletServer()
s.AddFlags(pflag.CommandLine)
flag.InitFlags()
logs.InitLogs()
...
例如:
cmd/kubelet/app/options/options.go:
fs.StringVar(&s.CNIConfDir, "cni-conf-dir", s.CNIConfDir, "<Warning: Alpha feature> The full path of the directory in which to search for CNI config files. Default: /etc/cni/net.d")
包含所有参数的信息的s，被传入app.Run():
cmd/kubelet/kubelet.go:
...
if err := app.Run(s, nil); err != nil {
fmt.Fprintf(os.Stderr, "error: %v\n", err)
os.Exit(1)
}
...
参考
