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719c57a29d
This is a simple solution to having the proxy keep up to date with the state of the cluster. Basically, it uses the cluster configuration provided at start up (i.e. with `-initial-cluster-state`) to determine where to reach peer(s) in the cluster, and then it will periodically hit the `/members` endpoint of those peer(s) (using the same mechanism that `-cluster-state=existing` does to initialise) to update the set of valid client URLs to proxy to. This does not address discovery (#1376), and it would probably be better to update the set of proxyURLs dynamically whenever we fetch the new state of the cluster; but it needs a bit more thinking to have this done in a clean way with the proxy interface. Example in Procfile works again.
51 lines
1.4 KiB
Go
51 lines
1.4 KiB
Go
/*
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Copyright 2014 CoreOS, Inc.
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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 proxy
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import (
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"net/http"
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)
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// GetProxyURLs is a function which should return the current set of URLs to
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// which client requests should be proxied. This function will be queried
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// periodically by the proxy Handler to refresh the set of available
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// backends.
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type GetProxyURLs func() []string
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func NewHandler(t *http.Transport, urlsFunc GetProxyURLs) http.Handler {
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return &reverseProxy{
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director: newDirector(urlsFunc),
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transport: t,
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}
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}
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func readonlyHandlerFunc(next http.Handler) func(http.ResponseWriter, *http.Request) {
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return func(w http.ResponseWriter, req *http.Request) {
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if req.Method != "GET" {
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w.WriteHeader(http.StatusNotImplemented)
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return
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}
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next.ServeHTTP(w, req)
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}
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}
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func NewReadonlyHandler(hdlr http.Handler) http.Handler {
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readonly := readonlyHandlerFunc(hdlr)
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return http.HandlerFunc(readonly)
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}
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