发布于 2015-11-10 13:34:53 | 439 次阅读 | 评论: 0 | 来源: PHPERZ
Docker 开源应用容器引擎
Docker 是一个开源的应用容器引擎，让开发者可以打包他们的应用以及依赖包到一个可移植的容器中，然后发布到任何流行的 Linux 机器上，也可以实现虚拟化。
写过应用框架的都应该知道有个路由模块，来看看docker的http请求是怎么路由的
docker的server.go文件中，首先入口是New的时候
func New(cfg *Config) *Server {
//需要创建Server的实例，因为命令的具体执行都是Server对象的函数
srv := &Server{
cfg: cfg,
start: make(chan struct{}),
}
//这里就是创建Router的操作
r := createRouter(srv)
srv.router = r
return srv
}
接下来看看createRouter的具体执行吧
func createRouter(s *Server) *mux.Router {
r := mux.NewRouter() //Router依赖第三包，地址：github.com/gorilla/mux
if os.Getenv("DEBUG") != "" {
profilerSetup(r, "/debug/")
}
//map->map[string]HTTPAPIFunc
m := map[string]map[string]HTTPAPIFunc{
"HEAD": { //key,value->server对应的处理函数
"/containers/{name:.*}/archive": s.headContainersArchive,
},
"GET": {
"/_ping": s.ping,
"/events": s.getEvents,
"/info": s.getInfo,
"/version": s.getVersion,
"/images/json": s.getImagesJSON,
"/images/search": s.getImagesSearch,
"/images/get": s.getImagesGet,
"/images/{name:.*}/get": s.getImagesGet,
"/images/{name:.*}/history": s.getImagesHistory,
"/images/{name:.*}/json": s.getImagesByName,
"/containers/ps": s.getContainersJSON,
"/containers/json": s.getContainersJSON,
"/containers/{name:.*}/export": s.getContainersExport,
"/containers/{name:.*}/changes": s.getContainersChanges,
"/containers/{name:.*}/json": s.getContainersByName,
"/containers/{name:.*}/top": s.getContainersTop,
"/containers/{name:.*}/logs": s.getContainersLogs,
"/containers/{name:.*}/stats": s.getContainersStats,
"/containers/{name:.*}/attach/ws": s.wsContainersAttach,
"/exec/{id:.*}/json": s.getExecByID,
"/containers/{name:.*}/archive": s.getContainersArchive,
"/volumes": s.getVolumesList,
"/volumes/{name:.*}": s.getVolumeByName,
},
"POST": {
"/auth": s.postAuth,
"/commit": s.postCommit,
"/build": s.postBuild,
"/images/create": s.postImagesCreate,
"/images/load": s.postImagesLoad,
"/images/{name:.*}/push": s.postImagesPush,
"/images/{name:.*}/tag": s.postImagesTag,
"/containers/create": s.postContainersCreate,
"/containers/{name:.*}/kill": s.postContainersKill,
"/containers/{name:.*}/pause": s.postContainersPause,
"/containers/{name:.*}/unpause": s.postContainersUnpause,
"/containers/{name:.*}/restart": s.postContainersRestart,
"/containers/{name:.*}/start": s.postContainersStart,
"/containers/{name:.*}/stop": s.postContainersStop,
"/containers/{name:.*}/wait": s.postContainersWait,
"/containers/{name:.*}/resize": s.postContainersResize,
"/containers/{name:.*}/attach": s.postContainersAttach,
"/containers/{name:.*}/copy": s.postContainersCopy,
"/containers/{name:.*}/exec": s.postContainerExecCreate,
"/exec/{name:.*}/start": s.postContainerExecStart,
"/exec/{name:.*}/resize": s.postContainerExecResize,
"/containers/{name:.*}/rename": s.postContainerRename,
"/volumes": s.postVolumesCreate,
},
"PUT": {
"/containers/{name:.*}/archive": s.putContainersArchive,
},
"DELETE": {
"/containers/{name:.*}": s.deleteContainers,
"/images/{name:.*}": s.deleteImages,
"/volumes/{name:.*}": s.deleteVolumes,
},
"OPTIONS": {
"": s.optionsHandler,
},
}
// If "api-cors-header" is not given, but "api-enable-cors" is true, we set cors to "*"
// otherwise, all head values will be passed to HTTP handler
corsHeaders := s.cfg.CorsHeaders
if corsHeaders == "" && s.cfg.EnableCors {
corsHeaders = "*"
}
for method, routes := range m {
for route, fct := range routes {
logrus.Debugf("Registering %s, %s", method, route)
localRoute := route //例如_ping
localFct := fct //例如Server.ping函数
localMethod := method //例如"GET"
// build the handler function
//golang的HTTPHandler
f := makeHTTPHandler(s.cfg.Logging, localMethod, localRoute, localFct, corsHeaders, version.Version(s.cfg.Version))
// 这里就是route的创建
if localRoute == "" {
r.Methods(localMethod).HandlerFunc(f)
} else {
r.Path("/v{version:[0-9.]+}" + localRoute).Methods(localMethod).HandlerFunc(f)
r.Path(localRoute).Methods(localMethod).HandlerFunc(f)
}
}
}
再去看看mux的例子说明：
//They are defined using the format {name} or {name:pattern}.
//If a regular expression pattern is not
// defined, the matched variable will be anything until the next slash
r := mux.NewRouter()
r.HandleFunc("/products/{key}", ProductHandler)
r.HandleFunc("/articles/{category}/", ArticlesCategoryHandler)
r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler
最终mux执行的golang http handler的interface ServeHTTP
func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
// Clean path to canonical form and redirect.
if p := cleanPath(req.URL.Path); p != req.URL.Path {
// Added 3 lines (Philip Schlump) - It was droping the query string and #whatever from query.
// This matches with fix in go 1.2 r.c. 4 for same problem. Go Issue:
// http://code.google.com/p/go/issues/detail?id=5252
url := *req.URL
url.Path = p
p = url.String()
w.Header().Set("Location", p)
w.WriteHeader(http.StatusMovedPermanently)
return
}
var match RouteMatch
var handler http.Handler
if r.Match(req, &match) {
handler = match.Handler //这里是关键步骤
setVars(req, match.Vars)
setCurrentRoute(req, match.Route)
}
if handler == nil {
handler = r.NotFoundHandler
if handler == nil {
handler = http.NotFoundHandler()
}
}
if !r.KeepContext {
defer context.Clear(req)
}
handler.ServeHTTP(w, req) //这里最终执行回调的匿名函数
}