mirror of https://github.com/grafana/grafana
pkg/web: closure-style middlewares (#51238)
* pkg/web: closure-style middlewares Switches the middleware execution model from web.Handlers in a slice to web.Middleware. Middlewares are temporarily kept in a slice to preserve ordering, but prior to execution they are applied, forming a giant call-stack, giving granular control over the execution flow. * pkg/middleware: adapt to web.Middleware * pkg/middleware/recovery: use c.Req over req c.Req gets updated by future handlers, while req stays static. The current recovery implementation needs this newer information * pkg/web: correct middleware ordering * pkg/webtest: adapt middleware * pkg/web/hack: set w and r onto web.Context By adopting std middlewares, it may happen they invoke next(w,r) without putting their modified w,r into the web.Context, leading old-style handlers to operate on outdated fields. pkg/web now takes care of this * pkg/middleware: selectively use future context * pkg/web: accept closure-style on Use() * webtest: Middleware testing adds a utility function to web/webtest to obtain a http.ResponseWriter, http.Request and http.Handler the same as a middleware that runs would receive * *: cleanup * pkg/web: don't wrap Middleware from Router * pkg/web: require chain to write response * *: remove temp files * webtest: don't require chain write * *: cleanuppull/53461/head
sh0rez
3 years ago
committed by
GitHub
parent
3893c46976
commit
534ece064b
@ -0,0 +1,73 @@ |
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package webtest |
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import ( |
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"net/http" |
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"net/http/httptest" |
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"github.com/grafana/grafana/pkg/web" |
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) |
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type Context struct { |
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Req *http.Request |
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Rw http.ResponseWriter |
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Next http.Handler |
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} |
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// Middleware is a utility for testing middlewares
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type Middleware struct { |
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// Before are run ahead of the returned context
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Before []web.Handler |
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// After are part of the http.Handler chain
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After []web.Handler |
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// The actual handler at the end of the chain
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Handler web.Handler |
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} |
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// MiddlewareContext returns a *http.Request, http.ResponseWriter and http.Handler
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// exactly as if it was passed to a middleware
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func MiddlewareContext(test Middleware, req *http.Request) *Context { |
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m := web.New() |
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// pkg/web requires the chain to write an HTTP response.
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// While this ensures a basic amount of correctness for real handler chains,
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// it is naturally incompatible with this package, as we terminate the chain early to pass its
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// state to the surrounding test.
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// By replacing the http.ResponseWriter and writing to the old one we make pkg/web happy.
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m.Use(func(next http.Handler) http.Handler { |
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
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w.WriteHeader(http.StatusOK) |
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rw := web.Rw(httptest.NewRecorder(), r) |
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next.ServeHTTP(rw, r) |
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}) |
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}) |
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for _, mw := range test.Before { |
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m.Use(mw) |
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} |
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ch := make(chan *Context) |
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m.Use(func(next http.Handler) http.Handler { |
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
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ch <- &Context{ |
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Req: r, |
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Rw: w, |
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Next: next, |
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} |
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}) |
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}) |
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for _, mw := range test.After { |
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m.Use(mw) |
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} |
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// set the provided (or noop) handler to exactly the queried path
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handler := test.Handler |
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if handler == nil { |
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handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}) |
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} |
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m.Handle(req.Method, req.URL.RequestURI(), []web.Handler{handler}) |
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go m.ServeHTTP(httptest.NewRecorder(), req) |
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return <-ch |
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} |
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