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

plugin/kubernetes/parse_test.go

@@ -0,0 +1,56 @@
+package kubernetes
+
+import (
+	"testing"
+
+	"github.com/coredns/coredns/request"
+
+	"github.com/miekg/dns"
+)
+
+func TestParseRequest(t *testing.T) {
+	tests := []struct {
+		query    string
+		expected string // output from r.String()
+	}{
+		// valid SRV request
+		{"_http._tcp.webs.mynamespace.svc.inter.webs.test.", "http.tcp..webs.mynamespace.svc"},
+		// wildcard acceptance
+		{"*.any.*.any.svc.inter.webs.test.", "*.any..*.any.svc"},
+		// A request of endpoint
+		{"1-2-3-4.webs.mynamespace.svc.inter.webs.test.", "*.*.1-2-3-4.webs.mynamespace.svc"},
+	}
+	for i, tc := range tests {
+		m := new(dns.Msg)
+		m.SetQuestion(tc.query, dns.TypeA)
+		state := request.Request{Zone: zone, Req: m}
+
+		r, e := parseRequest(state)
+		if e != nil {
+			t.Errorf("Test %d, expected no error, got '%v'.", i, e)
+		}
+		rs := r.String()
+		if rs != tc.expected {
+			t.Errorf("Test %d, expected (stringyfied) recordRequest: %s, got %s", i, tc.expected, rs)
+		}
+	}
+}
+
+func TestParseInvalidRequest(t *testing.T) {
+	invalid := []string{
+		"webs.mynamespace.pood.inter.webs.test.",                 // Request must be for pod or svc subdomain.
+		"too.long.for.what.I.am.trying.to.pod.inter.webs.tests.", // Too long.
+	}
+
+	for i, query := range invalid {
+		m := new(dns.Msg)
+		m.SetQuestion(query, dns.TypeA)
+		state := request.Request{Zone: zone, Req: m}
+
+		if _, e := parseRequest(state); e == nil {
+			t.Errorf("Test %d: expected error from %s, got none", i, query)
+		}
+	}
+}
+
+const zone = "intern.webs.tests."