76 lines
1.7 KiB
Go
76 lines
1.7 KiB
Go
package kubernetes
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import (
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"fmt"
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"io"
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"log"
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"net"
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"net/http"
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"github.com/coredns/coredns/middleware/pkg/healthcheck"
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)
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type proxyHandler struct {
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healthcheck.HealthCheck
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}
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type apiProxy struct {
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http.Server
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listener net.Listener
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handler proxyHandler
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}
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func (p *proxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
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upstream := p.Select()
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network := "tcp"
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if upstream.Network != "" {
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network = upstream.Network
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}
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address := upstream.Name
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d, err := net.Dial(network, address)
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if err != nil {
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log.Printf("[ERROR] Unable to establish connection to upstream %s://%s: %s", network, address, err)
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http.Error(w, fmt.Sprintf("Unable to establish connection to upstream %s://%s: %s", network, address, err), 500)
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return
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}
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hj, ok := w.(http.Hijacker)
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if !ok {
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log.Printf("[ERROR] Unable to establish connection: no hijacker")
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http.Error(w, "Unable to establish connection: no hijacker", 500)
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return
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}
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nc, _, err := hj.Hijack()
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if err != nil {
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log.Printf("[ERROR] Unable to hijack connection: %s", err)
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http.Error(w, fmt.Sprintf("Unable to hijack connection: %s", err), 500)
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return
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}
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defer nc.Close()
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defer d.Close()
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err = r.Write(d)
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if err != nil {
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log.Printf("[ERROR] Unable to copy connection to upstream %s://%s: %s", network, address, err)
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http.Error(w, fmt.Sprintf("Unable to copy connection to upstream %s://%s: %s", network, address, err), 500)
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return
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}
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errChan := make(chan error, 2)
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cp := func(dst io.Writer, src io.Reader) {
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_, err := io.Copy(dst, src)
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errChan <- err
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}
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go cp(d, nc)
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go cp(nc, d)
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<-errChan
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}
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func (p *apiProxy) Run() {
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p.handler.Start()
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p.Serve(p.listener)
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}
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func (p *apiProxy) Stop() {
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p.handler.Stop()
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p.listener.Close()
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}
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