Remove the word middleware (#1067)

* Rename middleware to plugin

first pass; mostly used 'sed', few spots where I manually changed
text.

This still builds a coredns binary.

* fmt error

* Rename AddMiddleware to AddPlugin

* Readd AddMiddleware to remain backwards compat

1 files changed, 0 insertions, 76 deletions

diff --git a/middleware/kubernetes/apiproxy.go b/middleware/kubernetes/apiproxy.go
deleted file mode 100644
index f6d2c00fa..000000000
--- a/middleware/kubernetes/apiproxy.go
+++ /dev/null
@@ -1,76 +0,0 @@
-package kubernetes
-
-import (
-	"fmt"
-	"io"
-	"log"
-	"net"
-	"net/http"
-
-	"github.com/coredns/coredns/middleware/pkg/healthcheck"
-)
-
-type proxyHandler struct {
-	healthcheck.HealthCheck
-}
-
-type apiProxy struct {
-	http.Server
-	listener net.Listener
-	handler  proxyHandler
-}
-
-func (p *proxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	upstream := p.Select()
-	network := "tcp"
-	if upstream.Network != "" {
-		network = upstream.Network
-	}
-	address := upstream.Name
-	d, err := net.Dial(network, address)
-	if err != nil {
-		log.Printf("[ERROR] Unable to establish connection to upstream %s://%s: %s", network, address, err)
-		http.Error(w, fmt.Sprintf("Unable to establish connection to upstream %s://%s: %s", network, address, err), 500)
-		return
-	}
-	hj, ok := w.(http.Hijacker)
-	if !ok {
-		log.Printf("[ERROR] Unable to establish connection: no hijacker")
-		http.Error(w, "Unable to establish connection: no hijacker", 500)
-		return
-	}
-	nc, _, err := hj.Hijack()
-	if err != nil {
-		log.Printf("[ERROR] Unable to hijack connection: %s", err)
-		http.Error(w, fmt.Sprintf("Unable to hijack connection: %s", err), 500)
-		return
-	}
-	defer nc.Close()
-	defer d.Close()
-
-	err = r.Write(d)
-	if err != nil {
-		log.Printf("[ERROR] Unable to copy connection to upstream %s://%s: %s", network, address, err)
-		http.Error(w, fmt.Sprintf("Unable to copy connection to upstream %s://%s: %s", network, address, err), 500)
-		return
-	}
-
-	errChan := make(chan error, 2)
-	cp := func(dst io.Writer, src io.Reader) {
-		_, err := io.Copy(dst, src)
-		errChan <- err
-	}
-	go cp(d, nc)
-	go cp(nc, d)
-	<-errChan
-}
-
-func (p *apiProxy) Run() {
-	p.handler.Start()
-	p.Serve(p.listener)
-}
-
-func (p *apiProxy) Stop() {
-	p.handler.Stop()
-	p.listener.Close()
-}