74 lines
2.2 KiB
Go
74 lines
2.2 KiB
Go
/*
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Copyright 2016 The Fission Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package router
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import (
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"errors"
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"log"
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"net/http"
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"net/http/httputil"
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"net/url"
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)
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type functionHandler struct {
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fmap *functionServiceMap
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poolManagerUrl string
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Function
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}
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func (*functionHandler) getServiceForFunction() (*url.URL, error) {
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return nil, errors.New("not implemented")
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}
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func (fh *functionHandler) handler(responseWriter http.ResponseWriter, request *http.Request) {
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serviceUrl, err := fh.fmap.lookup(&fh.Function)
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if err != nil {
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// Cache miss: request the Pool Manager to make a new service.
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serviceUrl, poolErr := fh.getServiceForFunction()
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if poolErr != nil {
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// now we're really screwed
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log.Printf("Failed to get service for function (%v,%v): %v",
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fh.Function.Name, fh.Function.Uid, poolErr)
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responseWriter.WriteHeader(500) // TODO: make this smarter based on the actual error
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return
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}
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// add it to the map
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fh.fmap.assign(&fh.Function, serviceUrl)
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}
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// Proxy off our request to the serviceUrl, and send the response back.
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// TODO: As an optimization we may want to cache proxies too -- this would get us
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// connection reuse and possibly better performance
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director := func(req *http.Request) {
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// send this request to serviceurl
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req.URL.Scheme = serviceUrl.Scheme
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req.URL.Host = serviceUrl.Host
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req.URL.Path = serviceUrl.Path
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// leave the query string intact (req.URL.RawQuery)
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if _, ok := req.Header["User-Agent"]; !ok {
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// explicitly disable User-Agent so it's not set to default value
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req.Header.Set("User-Agent", "")
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}
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}
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proxy := &httputil.ReverseProxy{Director: director}
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proxy.ServeHTTP(responseWriter, request)
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// TODO: handle failures and possibly retry here.
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}
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