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本文次要钻研一下dubbo-go-proxy的apiFilter

apiFilter

dubbo-go-proxy/pkg/filter/api/api.go

func Init() {    extension.SetFilterFunc(constant.HTTPApiFilter, apiFilterFunc())}
Init办法往extension设置了名为dgp.filters.http.api的apiFilterFunc

apiFilterFunc

dubbo-go-proxy/pkg/filter/api/api.go

// apiFilterFunc url match apifunc apiFilterFunc() context.FilterFunc {    return func(c context.Context) {        url := c.GetUrl()        method := c.GetMethod()        // [williamfeng323]TO-DO: get the API details from router which saved in constant.LocalMemoryApiDiscoveryService        if api, ok := api.EmptyApi.FindApi(url); ok {            if !api.MatchMethod(method) {                c.WriteWithStatus(http.StatusMethodNotAllowed, constant.Default405Body)                c.AddHeader(constant.HeaderKeyContextType, constant.HeaderValueTextPlain)                c.Abort()                return            }            if !api.IsOk(api.Name) {                c.WriteWithStatus(http.StatusNotAcceptable, constant.Default406Body)                c.AddHeader(constant.HeaderKeyContextType, constant.HeaderValueTextPlain)                c.Abort()                return            }            // [williamfeng323]TO-DO: the c.Api method need to be updated to use the newest API definition            c.Api(api)            c.Next()        } else {            c.WriteWithStatus(http.StatusNotFound, constant.Default404Body)            c.AddHeader(constant.HeaderKeyContextType, constant.HeaderValueTextPlain)            c.Abort()        }    }}
apiFilterFunc首先通过api.EmptyApi.FindApi(url)来查找对应的api，找不到则返回404；找到的话则先通过api.MatchMethod判断method是否匹配，不匹配的话返回405；之后通过api.IsOk判断该api的status是否up，不是的话返回406；最初执行c.Api(api)及c.Next()。

dubbo-go-proxy-filter

dubbo-go-proxy-filter@v0.1.0-rc1.0.20210120132524-c63f4eb13725/pkg/api/api.go

func (a *Api) FindApi(name string) (*Api, bool) {    if v, ok := CacheApi.Load(name); ok {        return v.(*Api), true    }    return nil, false}// MatchMethodfunc (a *Api) MatchMethod(method string) bool {    i := RequestMethodValue[method]    if a.RequestMethod == RequestMethod(i) {        return true    }    return false}// IsOk api status equals Upfunc (a *Api) IsOk(name string) bool {    if v, ok := CacheApi.Load(name); ok {        return v.(*Api).Status == Up    }    return false}
api.go提供了FindApi、MatchMethod、IsOk办法

小结

apiFilterFunc首先通过api.EmptyApi.FindApi(url)来查找对应的api，找不到则返回404；找到的话则先通过api.MatchMethod判断method是否匹配，不匹配的话返回405；之后通过api.IsOk判断该api的status是否up，不是的话返回406；最初执行c.Api(api)及c.Next()。

doc

  • dubbo-go-proxy