WIP: autopath as middleware (#859)

autopath as middleware

middleware/autopath/autopath_test.go

@@ -0,0 +1,165 @@
+package autopath
+
+import (
+	"testing"
+
+	"github.com/coredns/coredns/middleware"
+	"github.com/coredns/coredns/middleware/pkg/dnsrecorder"
+	"github.com/coredns/coredns/middleware/test"
+
+	"github.com/miekg/dns"
+	"golang.org/x/net/context"
+)
+
+var autopathTestCases = []test.Case{
+	{
+		// search path expansion.
+		Qname: "b.example.org.", Qtype: dns.TypeA,
+		Answer: []dns.RR{
+			test.CNAME("b.example.org. 3600 IN CNAME b.com."),
+			test.A("b.com." + defaultA),
+		},
+	},
+	{
+		// No search path expansion
+		Qname: "a.example.com.", Qtype: dns.TypeA,
+		Answer: []dns.RR{
+			test.A("a.example.com." + defaultA),
+		},
+	},
+}
+
+func newTestAutoPath() *AutoPath {
+	ap := new(AutoPath)
+	ap.Next = nextHandler(map[string]int{
+		"b.example.org.": dns.RcodeNameError,
+		"b.com.":         dns.RcodeSuccess,
+		"a.example.com.": dns.RcodeSuccess,
+	})
+
+	ap.search = []string{"example.org.", "example.com.", "com.", ""}
+	return ap
+}
+
+func TestAutoPath(t *testing.T) {
+	ap := newTestAutoPath()
+	ctx := context.TODO()
+
+	for _, tc := range autopathTestCases {
+		m := tc.Msg()
+
+		rec := dnsrecorder.New(&test.ResponseWriter{})
+		_, err := ap.ServeDNS(ctx, rec, m)
+		if err != nil {
+			t.Errorf("expected no error, got %v\n", err)
+			continue
+		}
+
+		resp := rec.Msg
+
+		if !test.Header(t, tc, resp) {
+			t.Logf("%v\n", resp)
+			continue
+		}
+		if !test.Section(t, tc, test.Answer, resp.Answer) {
+			t.Logf("%v\n", resp)
+		}
+		if !test.Section(t, tc, test.Ns, resp.Ns) {
+			t.Logf("%v\n", resp)
+		}
+		if !test.Section(t, tc, test.Extra, resp.Extra) {
+			t.Logf("%v\n", resp)
+		}
+	}
+}
+
+var autopathNoAnswerTestCases = []test.Case{
+	{
+		// search path expansion, no answer
+		Qname: "c.example.org.", Qtype: dns.TypeA,
+		Answer: []dns.RR{
+			test.CNAME("b.example.org. 3600 IN CNAME b.com."),
+			test.A("b.com." + defaultA),
+		},
+	},
+}
+
+func TestAutoPathNoAnswer(t *testing.T) {
+	ap := newTestAutoPath()
+	ctx := context.TODO()
+
+	for _, tc := range autopathNoAnswerTestCases {
+		m := tc.Msg()
+
+		rec := dnsrecorder.New(&test.ResponseWriter{})
+		rcode, err := ap.ServeDNS(ctx, rec, m)
+		if err != nil {
+			t.Errorf("expected no error, got %v\n", err)
+			continue
+		}
+		if middleware.ClientWrite(rcode) {
+			t.Fatalf("expected no client write, got one for rcode %d", rcode)
+		}
+	}
+}
+
+// nextHandler returns a Handler that returns an answer for the question in the
+// request per the domain->answer map. On success an RR will be returned: "qname 3600 IN A 127.0.0.53"
+func nextHandler(mm map[string]int) test.Handler {
+	return test.HandlerFunc(func(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
+		rcode, ok := mm[r.Question[0].Name]
+		if !ok {
+			return dns.RcodeServerFailure, nil
+		}
+
+		m := new(dns.Msg)
+		m.SetReply(r)
+
+		switch rcode {
+		case dns.RcodeNameError:
+			m.Rcode = rcode
+			m.Ns = []dns.RR{soa}
+			w.WriteMsg(m)
+			return m.Rcode, nil
+
+		case dns.RcodeSuccess:
+			m.Rcode = rcode
+			a, _ := dns.NewRR(r.Question[0].Name + defaultA)
+			m.Answer = []dns.RR{a}
+
+			w.WriteMsg(m)
+			return m.Rcode, nil
+		default:
+			panic("nextHandler: unhandled rcode")
+		}
+
+		return dns.RcodeServerFailure, nil
+	})
+}
+
+const defaultA = " 3600 IN A 127.0.0.53"
+
+var soa = func() dns.RR {
+	s, _ := dns.NewRR("example.org.		1800	IN	SOA	example.org. example.org. 1502165581 14400 3600 604800 14400")
+	return s
+}()
+
+func TestInSearchPath(t *testing.T) {
+	a := AutoPath{search: []string{"default.svc.cluster.local.", "svc.cluster.local.", "cluster.local."}}
+
+	tests := []struct {
+		qname string
+		b     bool
+	}{
+		{"google.com", false},
+		{"default.svc.cluster.local.", true},
+		{"a.default.svc.cluster.local.", true},
+		{"a.b.svc.cluster.local.", false},
+	}
+	for i, tc := range tests {
+		got := a.FirstInSearchPath(tc.qname)
+		if got != tc.b {
+			t.Errorf("Test %d, got %d, expected %d", i, got, tc.b)
+		}
+	}
+}