Make CoreDNS a server type plugin for Caddy (#220)

* Make CoreDNS a server type plugin for Caddy

Remove code we don't need and port all middleware over. Fix all tests
and rework the documentation.

Also make `go generate` build a caddy binary which we then copy into
our directory. This means `go build`-builds remain working as-is.

And new etc instances in each etcd test for better isolation.
Fix more tests and rework test.Server with the newer support Caddy offers.

Fix Makefile to support new mode of operation.

middleware/dnssec/cache_test.go

@@ -22,7 +22,7 @@ func TestCacheSet(t *testing.T) {
 	m := testMsg()
 	state := middleware.State{Req: m}
 	k := key(m.Answer) // calculate *before* we add the sig
-	d := NewDnssec([]string{"miek.nl."}, []*DNSKEY{dnskey}, nil)
+	d := New([]string{"miek.nl."}, []*DNSKEY{dnskey}, nil)
 	m = d.Sign(state, "miek.nl.", time.Now().UTC())
 
 	_, ok := d.get(k)

middleware/dnssec/dnssec.go

@@ -11,14 +11,15 @@ import (
 )
 
 type Dnssec struct {
-	Next     middleware.Handler
+	Next middleware.Handler
+
 	zones    []string
 	keys     []*DNSKEY
 	inflight *singleflight.Group
 	cache    *gcache.Cache
 }
 
-func NewDnssec(zones []string, keys []*DNSKEY, next middleware.Handler) Dnssec {
+func New(zones []string, keys []*DNSKEY, next middleware.Handler) Dnssec {
 	return Dnssec{Next: next,
 		zones:    zones,
 		keys:     keys,

middleware/dnssec/dnssec_test.go

@@ -69,7 +69,7 @@ func TestSigningDifferentZone(t *testing.T) {
 
 	m := testMsgEx()
 	state := middleware.State{Req: m}
-	d := NewDnssec([]string{"example.org."}, []*DNSKEY{key}, nil)
+	d := New([]string{"example.org."}, []*DNSKEY{key}, nil)
 	m = d.Sign(state, "example.org.", time.Now().UTC())
 	if !section(m.Answer, 1) {
 		t.Errorf("answer section should have 1 sig")
@@ -158,7 +158,7 @@ func testDelegationMsg() *dns.Msg {
 
 func newDnssec(t *testing.T, zones []string) (Dnssec, func(), func()) {
 	k, rm1, rm2 := newKey(t)
-	d := NewDnssec(zones, []*DNSKEY{k}, nil)
+	d := New(zones, []*DNSKEY{k}, nil)
 	return d, rm1, rm2
 }
 

middleware/dnssec/handler_test.go

@@ -77,7 +77,7 @@ func TestLookupZone(t *testing.T) {
 	dnskey, rm1, rm2 := newKey(t)
 	defer rm1()
 	defer rm2()
-	dh := NewDnssec([]string{"miek.nl."}, []*DNSKEY{dnskey}, fm)
+	dh := New([]string{"miek.nl."}, []*DNSKEY{dnskey}, fm)
 	ctx := context.TODO()
 
 	for _, tc := range dnsTestCases {
@@ -115,7 +115,7 @@ func TestLookupDNSKEY(t *testing.T) {
 	dnskey, rm1, rm2 := newKey(t)
 	defer rm1()
 	defer rm2()
-	dh := NewDnssec([]string{"miek.nl."}, []*DNSKEY{dnskey}, test.ErrorHandler())
+	dh := New([]string{"miek.nl."}, []*DNSKEY{dnskey}, test.ErrorHandler())
 	ctx := context.TODO()
 
 	for _, tc := range dnssecTestCases {

middleware/dnssec/setup.go

@@ -0,0 +1,91 @@
+package dnssec
+
+import (
+	"strings"
+
+	"github.com/miekg/coredns/core/dnsserver"
+	"github.com/miekg/coredns/middleware"
+
+	"github.com/mholt/caddy"
+)
+
+func init() {
+	caddy.RegisterPlugin("dnssec", caddy.Plugin{
+		ServerType: "dns",
+		Action:     setup,
+	})
+}
+
+func setup(c *caddy.Controller) error {
+	zones, keys, err := dnssecParse(c)
+	if err != nil {
+		return err
+	}
+
+	dnsserver.GetConfig(c).AddMiddleware(func(next dnsserver.Handler) dnsserver.Handler {
+		return New(zones, keys, next)
+	})
+
+	return nil
+}
+
+func dnssecParse(c *caddy.Controller) ([]string, []*DNSKEY, error) {
+	zones := []string{}
+
+	keys := []*DNSKEY{}
+	for c.Next() {
+		if c.Val() == "dnssec" {
+			// dnssec [zones...]
+			zones = make([]string, len(c.ServerBlockKeys))
+			copy(zones, c.ServerBlockKeys)
+			args := c.RemainingArgs()
+			if len(args) > 0 {
+				zones = args
+			}
+
+			for c.NextBlock() {
+				k, e := keyParse(c)
+				if e != nil {
+					return nil, nil, e
+				}
+				keys = append(keys, k...)
+			}
+		}
+	}
+	for i, _ := range zones {
+		zones[i] = middleware.Host(zones[i]).Normalize()
+	}
+	return zones, keys, nil
+}
+
+func keyParse(c *caddy.Controller) ([]*DNSKEY, error) {
+	keys := []*DNSKEY{}
+
+	what := c.Val()
+	if !c.NextArg() {
+		return nil, c.ArgErr()
+	}
+	value := c.Val()
+	switch what {
+	case "key":
+		if value == "file" {
+			ks := c.RemainingArgs()
+			for _, k := range ks {
+				base := k
+				// Kmiek.nl.+013+26205.key, handle .private or without extension: Kmiek.nl.+013+26205
+				if strings.HasSuffix(k, ".key") {
+					base = k[:len(k)-4]
+				}
+				if strings.HasSuffix(k, ".private") {
+					base = k[:len(k)-8]
+				}
+				k, err := ParseKeyFile(base+".key", base+".private")
+				if err != nil {
+					return nil, err
+				}
+				keys = append(keys, k)
+			}
+		}
+	}
+	return keys, nil
+}

middleware/dnssec/setup_test.go

@@ -0,0 +1,56 @@
+package dnssec
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/mholt/caddy"
+)
+
+func TestSetupDnssec(t *testing.T) {
+	tests := []struct {
+		input              string
+		shouldErr          bool
+		expectedZones      []string
+		expectedKeys       []string
+		expectedErrContent string
+	}{
+		{
+			`dnssec`, false, nil, nil, "",
+		},
+		{
+			`dnssec miek.nl`, false, []string{"miek.nl."}, nil, "",
+		},
+	}
+
+	for i, test := range tests {
+		c := caddy.NewTestController("dns", test.input)
+		zones, keys, err := dnssecParse(c)
+
+		if test.shouldErr && err == nil {
+			t.Errorf("Test %d: Expected error but found %s for input %s", i, err, test.input)
+		}
+
+		if err != nil {
+			if !test.shouldErr {
+				t.Errorf("Test %d: Expected no error but found one for input %s. Error was: %v", i, test.input, err)
+			}
+
+			if !strings.Contains(err.Error(), test.expectedErrContent) {
+				t.Errorf("Test %d: Expected error to contain: %v, found error: %v, input: %s", i, test.expectedErrContent, err, test.input)
+			}
+		}
+		if !test.shouldErr {
+			for i, z := range test.expectedZones {
+				if zones[i] != z {
+					t.Errorf("Dnssec not correctly set for input %s. Expected: %s, actual: %s", test.input, z, zones[i])
+				}
+			}
+			for i, k := range test.expectedKeys {
+				if k != keys[i].K.Header().Name {
+					t.Errorf("Dnssec not correctly set for input %s. Expected: '%s', actual: '%s'", test.input, k, keys[i].K.Header().Name)
+				}
+			}
+		}
+	}
+}