学习链接operator实战
关于k8s常用lib库项目介绍
- apimachinery
apimachinery项目概览
apimachinery子项目主要是k8s服务端和客户段项目都共同依赖的一些公共方法,struct,工具的定义. 主要是服务于kubernetes,client-go,apiserver这三个项目.
api目录
（1）apitesting
这里主要是帮我们做了一些默认字段的填充，就比如你创建的时候有些字段没设置，这里就会设置默认的
（2）equality
用来做转换的一些东西
（3）errors
k8s中的错误信息，以及判断错误类型
（4）meta
api版本转换以及api注册的时候会用到这里面的代码
（5）resource
类型的转换以及单位的转换
（6）validation
主要用来做校验
其他目录
apis跟api类似会一些label的判断之类的
conversion主要是做了一些api转换用的
fileds主要是做了一些字段判断
type Fields interface {
// Has returns whether the provided field exists.
Has(field string) (exists bool)
// Get returns the value for the provided field.
Get(field string) (value string)
}
// Set is a map of field:value. It implements Fields.
type Set map[string]string
label就是label的转换 以及label的操作
selector 就是判断标签是否存在当中或者是否匹配一个正则表达式
runtime 定义了k8s最核心的东西schema，所有的api注册都需要注册到schema中
// staging/src/k8s.io/apimachinery/pkg/runtime/interfaces.go
//这块定义了转换
type Serializer interface {
Encoder
Decoder
}
//staging/src/k8s.io/apimachinery/pkg/runtime/schema.go
type Scheme struct {
// versionMap allows one to figure out the go type of an object with
// the given version and name.
gvkToType map[schema.GroupVersionKind]reflect.Type
// typeToGroupVersion allows one to find metadata for a given go object.
// The reflect.Type we index by should *not* be a pointer.
typeToGVK map[reflect.Type][]schema.GroupVersionKind
// unversionedTypes are transformed without conversion in ConvertToVersion.
unversionedTypes map[reflect.Type]schema.GroupVersionKind
// unversionedKinds are the names of kinds that can be created in the context of any group
// or version
// TODO: resolve the status of unversioned types.
unversionedKinds map[string]reflect.Type
// Map from version and resource to the corresponding func to convert
// resource field labels in that version to internal version.
fieldLabelConversionFuncs map[schema.GroupVersionKind]FieldLabelConversionFunc
// defaulterFuncs is an array of interfaces to be called with an object to provide defaulting
// the provided object must be a pointer.
defaulterFuncs map[reflect.Type]func(interface{})
// converter stores all registered conversion functions. It also has
// default converting behavior.
converter *conversion.Converter
// versionPriority is a map of groups to ordered lists of versions for those groups indicating the
// default priorities of these versions as registered in the scheme
versionPriority map[string][]string
// observedVersions keeps track of the order we've seen versions during type registration
observedVersions []schema.GroupVersion
// schemeName is the name of this scheme. If you don't specify a name, the stack of the NewScheme caller will be used.
// This is useful for error reporting to indicate the origin of the scheme.
schemeName string
}
k8s本身调用apiserver 然后调用runtime的schema的代码吧api注册（这里会用api的install）在schema中会起一个对应的healder来对外服务，下图可以看到每个api都会有install
//pkg/apis/apps/install/install.go
func Install(scheme *runtime.Scheme) {
utilruntime.Must(apps.AddToScheme(scheme))
utilruntime.Must(v1beta1.AddToScheme(scheme))
utilruntime.Must(v1beta2.AddToScheme(scheme))
utilruntime.Must(v1.AddToScheme(scheme))
utilruntime.Must(scheme.SetVersionPriority(v1.SchemeGroupVersion, v1beta2.SchemeGroupVersion, v1beta1.SchemeGroupVersion))
}
test就是用来做测试的
type定义了一些类型
util定义了一些资源转换
version定义了版本
wathc的核心是event
//staging/src/k8s.io/apimachinery/pkg/watch/watch.go
type Interface interface {
// Stops watching. Will close the channel returned by ResultChan(). Releases
// any resources used by the watch.
Stop()
// Returns a chan which will receive all the events. If an error occurs
// or Stop() is called, this channel will be closed, in which case the
// watch should be completely cleaned up.
//我们可以从这个管道获取一个事件
ResultChan() <-chan Event
}
// EventType defines the possible types of events.
type EventType string
//定义了k8s event的类型
const (
Added EventType = "ADDED"
Modified EventType = "MODIFIED"
Deleted EventType = "DELETED"
Bookmark EventType = "BOOKMARK"
Error EventType = "ERROR"
DefaultChanSize int32 = 100
)
// Event represents a single event to a watched resource.
// +k8s:deepcopy-gen=true
type Event struct {
Type EventType
// Object is:
// * If Type is Added or Modified: the new state of the object.
// * If Type is Deleted: the state of the object immediately before deletion.
// * If Type is Bookmark: the object (instance of a type being watched) where
// only ResourceVersion field is set. On successful restart of watch from a
// bookmark resourceVersion, client is guaranteed to not get repeat event
// nor miss any events.
// * If Type is Error: *api.Status is recommended; other types may make sense
// depending on context.
Object runtime.Object
}
//type可以理解为什么样的事件
//object可以理解为对象
//那么结合起来就是一个什么样的事件发生在谁的身上
// staging/src/k8s.io/apimachinery/pkg/watch/mux.go
//事件广播器
//那么肯定有事件监听器 写入管道，广播器从管道拿出来
type Broadcaster struct {
// TODO: see if this lock is needed now that new watchers go through
// the incoming channel.
lock sync.Mutex
watchers map[int64]*broadcasterWatcher
nextWatcher int64
distributing sync.WaitGroup
//从incoming中拿到事件 然后循环watchers 把事件发送给所有的watcher
incoming chan Event
// How large to make watcher's channel.
watchQueueLength int
// If one of the watch channels is full, don't wait for it to become empty.
// Instead just deliver it to the watchers that do have space in their
// channels and move on to the next event.
// It's more fair to do this on a per-watcher basis than to do it on the
// "incoming" channel, which would allow one slow watcher to prevent all
// other watchers from getting new events.
//这里定义了一个行为，等incoming满了之后是等待还是删除
fullChannelBehavior FullChannelBehavior
}
type FullChannelBehavior int
const (
WaitIfChannelFull FullChannelBehavior = iota
DropIfChannelFull
)
//staging/src/k8s.io/apimachinery/pkg/watch/filter.go
//事件进来做一些填充在输出
func Filter(w Interface, f FilterFunc) Interface {
fw := &filteredWatch{
incoming: w,
result: make(chan Event),
f: f,
}
go fw.loop()
return fw
}