mw/autopath: integration test with erratic (#930)

Add integration test with erratic. For this erratic now also returns an
autopath searchpath. This tests the whole chain; i.e registring a
searchfunction and calling that from autopath.

This tests does a autopathing domain and a non-autopathing one.

9 files changed, 126 insertions, 22 deletions

diff --git a/middleware/autopath/README.md b/middleware/autopath/README.md
index 37ed789c6..4f0507891 100644
--- a/middleware/autopath/README.md
+++ b/middleware/autopath/README.md
@@ -22,6 +22,7 @@ autopath [ZONE..] RESOLV-CONF
 Currently the following set of middleware has implemented *autopath*:
 
 * *kubernetes*
+* *erratic*
 
 ## Examples
 
diff --git a/middleware/autopath/autopath.go b/middleware/autopath/autopath.go
index 2c581eadd..d3a8c84d2 100644
--- a/middleware/autopath/autopath.go
+++ b/middleware/autopath/autopath.go
@@ -33,7 +33,7 @@ func (m Middleware ) AutoPath(state request.Request) []string {
 */
 
 import (
-	"errors"
+	"log"
 
 	"github.com/coredns/coredns/middleware"
 	"github.com/coredns/coredns/middleware/pkg/dnsutil"
@@ -61,35 +61,33 @@ type AutoPath struct {
 // ServeDNS implements the middleware.Handle interface.
 func (a *AutoPath) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}
-	if state.QClass() != dns.ClassINET {
-		return dns.RcodeServerFailure, middleware.Error(a.Name(), errors.New("can only deal with ClassINET"))
-	}
 
 	zone := middleware.Zones(a.Zones).Matches(state.Name())
 	if zone == "" {
 		return middleware.NextOrFailure(a.Name(), a.Next, ctx, w, r)
 	}
 
-	// Check if autopath should be done, searchFunc takes precedence over the local configured
-	// search path.
+	// Check if autopath should be done, searchFunc takes precedence over the local configured search path.
 	var err error
 	searchpath := a.search
+
 	if a.searchFunc != nil {
 		searchpath = a.searchFunc(state)
-		if len(searchpath) == 0 {
-			return middleware.NextOrFailure(a.Name(), a.Next, ctx, w, r)
-		}
 	}
 
-	match := a.FirstInSearchPath(state.Name())
-	if !match {
+	if len(searchpath) == 0 {
+		log.Printf("[WARNING] No search path available for autopath")
+		return middleware.NextOrFailure(a.Name(), a.Next, ctx, w, r)
+	}
+
+	if !firstInSearchPath(state.Name(), searchpath) {
 		return middleware.NextOrFailure(a.Name(), a.Next, ctx, w, r)
 	}
 
 	origQName := state.QName()
 
 	// Establish base name of the query. I.e what was originally asked.
-	base, err := dnsutil.TrimZone(state.QName(), a.search[0]) // TODO(miek): we loose the original case of the query here.
+	base, err := dnsutil.TrimZone(state.QName(), searchpath[0]) // TODO(miek): we loose the original case of the query here.
 	if err != nil {
 		return dns.RcodeServerFailure, err
 	}
@@ -140,16 +138,16 @@ func (a *AutoPath) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Ms
 	return firstRcode, firstErr
 }
 
-// FirstInSearchPath checks if name is equal to are a sibling of the first element in the search path.
-func (a *AutoPath) FirstInSearchPath(name string) bool {
-	if name == a.search[0] {
+// Name implements the Handler interface.
+func (a *AutoPath) Name() string { return "autopath" }
+
+// firstInSearchPath checks if name is equal to are a sibling of the first element in the search path.
+func firstInSearchPath(name string, searchpath []string) bool {
+	if name == searchpath[0] {
 		return true
 	}
-	if dns.IsSubDomain(a.search[0], name) {
+	if dns.IsSubDomain(searchpath[0], name) {
 		return true
 	}
 	return false
 }
-
-// Name implements the Handler interface.
-func (a *AutoPath) Name() string { return "autopath" }
diff --git a/middleware/autopath/autopath_test.go b/middleware/autopath/autopath_test.go
index ca1290e26..b99744ab8 100644
--- a/middleware/autopath/autopath_test.go
+++ b/middleware/autopath/autopath_test.go
@@ -158,7 +158,7 @@ func TestInSearchPath(t *testing.T) {
 		{"a.b.svc.cluster.local.", false},
 	}
 	for i, tc := range tests {
-		got := a.FirstInSearchPath(tc.qname)
+		got := firstInSearchPath(tc.qname, a.search)
 		if got != tc.b {
 			t.Errorf("Test %d, got %v, expected %v", i, got, tc.b)
 		}
diff --git a/middleware/autopath/setup.go b/middleware/autopath/setup.go
index 1855dd440..f9b12d98e 100644
--- a/middleware/autopath/setup.go
+++ b/middleware/autopath/setup.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/coredns/coredns/core/dnsserver"
 	"github.com/coredns/coredns/middleware"
+	"github.com/coredns/coredns/middleware/erratic"
 	"github.com/coredns/coredns/middleware/kubernetes"
 
 	"github.com/mholt/caddy"
@@ -32,8 +33,11 @@ func setup(c *caddy.Controller) error {
 		if m == nil {
 			return nil
 		}
-		if k, ok := m.(kubernetes.Kubernetes); ok {
-			ap.searchFunc = k.AutoPath
+		if x, ok := m.(kubernetes.Kubernetes); ok {
+			ap.searchFunc = x.AutoPath
+		}
+		if x, ok := m.(*erratic.Erratic); ok {
+			ap.searchFunc = x.AutoPath
 		}
 		return nil
 	})
@@ -50,6 +54,7 @@ func setup(c *caddy.Controller) error {
 // need to register themselves with dnsserver.RegisterHandler.
 var allowedMiddleware = map[string]bool{
 	"@kubernetes": true,
+	"@erratic":    true,
 }
 
 func autoPathParse(c *caddy.Controller) (*AutoPath, string, error) {
diff --git a/middleware/autopath/setup_test.go b/middleware/autopath/setup_test.go
index b31110ddb..0f086c5bb 100644
--- a/middleware/autopath/setup_test.go
+++ b/middleware/autopath/setup_test.go
@@ -33,6 +33,7 @@ func TestSetupAutoPath(t *testing.T) {
 		{`autopath ` + resolv, false, "", "", []string{"bar.com.", "baz.com.", ""}, ""},
 		// negative
 		{`autopath kubernetes`, true, "", "", nil, "open kubernetes: no such file or directory"},
+		{`autopath`, true, "", "", nil, "no resolv-conf"},
 	}
 
 	for i, test := range tests {
diff --git a/middleware/erratic/README.md b/middleware/erratic/README.md
index e2989da96..a84146fbb 100644
--- a/middleware/erratic/README.md
+++ b/middleware/erratic/README.md
@@ -7,6 +7,9 @@ The *erratic* middleware will respond to every A or AAAA query. For any other ty
 a SERVFAIL response. The reply for A will return 192.0.2.53 (see RFC 5737), for AAAA it returns
 2001:DB8::53 (see RFC 3849).
 
+*erratic* can also be used in conjunction with the *autopath* middleware. This is mostly to aid in
+ testing.
+
 ## Syntax
 
 ~~~ txt
diff --git a/middleware/erratic/autopath.go b/middleware/erratic/autopath.go
new file mode 100644
index 000000000..79b0ec847
--- /dev/null
+++ b/middleware/erratic/autopath.go
@@ -0,0 +1,8 @@
+package erratic
+
+import "github.com/coredns/coredns/request"
+
+// AutoPath implements the AutoPathFunc call from the autopath middleware.
+func (e *Erratic) AutoPath(state request.Request) []string {
+	return []string{"a.example.org.", "b.example.org.", ""}
+}
diff --git a/middleware/erratic/setup.go b/middleware/erratic/setup.go
index 98db02247..1f4d0942d 100644
--- a/middleware/erratic/setup.go
+++ b/middleware/erratic/setup.go
@@ -28,6 +28,9 @@ func setupErratic(c *caddy.Controller) error {
 		return e
 	})
 
+	// Also register erratic for use in autopath.
+	dnsserver.GetConfig(c).RegisterHandler(e)
+
 	return nil
 }
 
diff --git a/test/erratic_autopath_test.go b/test/erratic_autopath_test.go
new file mode 100644
index 000000000..cd9a077d1
--- /dev/null
+++ b/test/erratic_autopath_test.go
@@ -0,0 +1,85 @@
+package test
+
+import (
+	"testing"
+
+	"github.com/miekg/dns"
+)
+
+func TestLookupAutoPathErratic(t *testing.T) {
+	corefile := `.:0 {
+	erratic
+	autopath @erratic
+	proxy . 8.8.8.8:53
+	debug
+    }
+`
+	i, err := CoreDNSServer(corefile)
+	if err != nil {
+		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
+	}
+
+	udp, _ := CoreDNSServerPorts(i, 0)
+	if udp == "" {
+		t.Fatalf("Could not get UDP listening port")
+	}
+	defer i.Stop()
+
+	tests := []struct {
+		qname          string
+		expectedAnswer string
+		expectedType   uint16
+	}{
+		{"google.com.a.example.org.", "google.com.a.example.org.", dns.TypeCNAME},
+		{"google.com.", "google.com.", dns.TypeA},
+	}
+
+	for i, tc := range tests {
+		m := new(dns.Msg)
+		// erratic always returns this search path: "a.example.org.", "b.example.org.", "".
+		m.SetQuestion(tc.qname, dns.TypeA)
+
+		r, err := dns.Exchange(m, udp)
+		if err != nil {
+			t.Fatalf("Test %d, failed to sent query: %q", i, err)
+		}
+		if len(r.Answer) == 0 {
+			t.Fatalf("Test %d, answer section should have RRs", i)
+		}
+		if x := r.Answer[0].Header().Name; x != tc.expectedAnswer {
+			t.Fatalf("Test %d, expected answer %s, got %s", i, tc.expectedAnswer, x)
+		}
+		if x := r.Answer[0].Header().Rrtype; x != tc.expectedType {
+			t.Fatalf("Test %d, expected answer type %d, got %d", i, tc.expectedType, x)
+		}
+	}
+}
+
+func TestAutoPathErraticNotLoaded(t *testing.T) {
+	corefile := `.:0 {
+	autopath @erratic
+	proxy . 8.8.8.8:53
+	debug
+    }
+`
+	i, err := CoreDNSServer(corefile)
+	if err != nil {
+		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
+	}
+
+	udp, _ := CoreDNSServerPorts(i, 0)
+	if udp == "" {
+		t.Fatalf("Could not get UDP listening port")
+	}
+	defer i.Stop()
+
+	m := new(dns.Msg)
+	m.SetQuestion("google.com.a.example.org.", dns.TypeA)
+	r, err := dns.Exchange(m, udp)
+	if err != nil {
+		t.Fatalf("Failed to sent query: %q", err)
+	}
+	if r.Rcode != dns.RcodeNameError {
+		t.Fatalf("Expected NXDOMAIN, got %d", r.Rcode)
+	}
+}