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Commit 760e6670 authored by Miek Gieben's avatar Miek Gieben Committed by GitHub
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middleware/kubernetes: autopath in sub package (#848) 

Put the autopath stuff in a separate sub package. Tests are still
included in the main kubernetes directory.

Next steps (after this is merged), is pulling the autopath handling
into the subpackage and fixing the tests.
parent 050eccd6
Hide whitespace changes
Inline Side-by-side
Showing with 103 additions and 95 deletions
middleware/kubernetes/autopath.go → middleware/kubernetes/autopath/autopath.go
View file @ 760e6670
package kubernetes
package autopath
import "github.com/miekg/dns"
// AutoPathWriter implements a ResponseWriter that also does the following:
// Writer implements a ResponseWriter that also does the following:
// * reverts question section of a packet to its original state.
// This is done to avoid the 'Question section mismatch:' error in client.
// * Defers write to the client if the response code is NXDOMAIN. This is needed
......@@ -10,40 +10,48 @@ import "github.com/miekg/dns"
// * Allow forced write to client regardless of response code. This is needed to
// write the packet to the client if the final search in the path fails to
// produce results.
// * Overwrites response code with AutoPathWriter.Rcode if the response code
// * Overwrites response code with Writer.Rcode if the response code
// is NXDOMAIN (NameError). This is needed to support the AutoPath.OnNXDOMAIN
// function, which returns a NOERROR to client instead of NXDOMAIN if the final
// search in the path fails to produce results.
type AutoPathWriter struct {
type Writer struct {
dns.ResponseWriter
original dns.Question
Rcode int
Sent bool
}
// NewAutoPathWriter returns a pointer to a new AutoPathWriter
func NewAutoPathWriter(w dns.ResponseWriter, r *dns.Msg) *AutoPathWriter {
return &AutoPathWriter{
// AutoPath enables server side search path lookups for pods.
type AutoPath struct {
NDots int
ResolvConfFile string
HostSearchPath []string
OnNXDOMAIN int
}
// NewWriter returns a pointer to a new Writer
func NewWriter(w dns.ResponseWriter, r *dns.Msg) *Writer {
return &Writer{
ResponseWriter: w,
original: r.Question[0],
Rcode: dns.RcodeSuccess,
}
}
// WriteMsg writes to client, unless response will be NXDOMAIN
func (apw *AutoPathWriter) WriteMsg(res *dns.Msg) error {
// WriteMsg writes to client, unless response will be NXDOMAIN.
func (apw *Writer) WriteMsg(res *dns.Msg) error {
return apw.overrideMsg(res, false)
}
// ForceWriteMsg forces the write to client regardless of response code
func (apw *AutoPathWriter) ForceWriteMsg(res *dns.Msg) error {
// ForceWriteMsg forces the write to client regardless of response code.
func (apw *Writer) ForceWriteMsg(res *dns.Msg) error {
return apw.overrideMsg(res, true)
}
// overrideMsg overrides rcode, reverts question, adds CNAME, and calls the
// underlying ResponseWriter's WriteMsg method unless the write is deferred,
// or force = true.
func (apw *AutoPathWriter) overrideMsg(res *dns.Msg, force bool) error {
func (apw *Writer) overrideMsg(res *dns.Msg, force bool) error {
if res.Rcode == dns.RcodeNameError {
res.Rcode = apw.Rcode
}
......@@ -56,7 +64,7 @@ func (apw *AutoPathWriter) overrideMsg(res *dns.Msg, force bool) error {
}
res.Answer = append(res.Answer, nil)
copy(res.Answer[1:], res.Answer)
res.Answer[0] = newCNAME(apw.original.Name, dns.Fqdn(a.Header().Name), a.Header().Ttl)
res.Answer[0] = CNAME(apw.original.Name, a.Header().Name, a.Header().Ttl)
}
res.Question[0] = apw.original
apw.Sent = true
......@@ -64,14 +72,14 @@ func (apw *AutoPathWriter) overrideMsg(res *dns.Msg, force bool) error {
}
// Write is a wrapper that records the size of the message that gets written.
func (apw *AutoPathWriter) Write(buf []byte) (int, error) {
func (apw *Writer) Write(buf []byte) (int, error) {
n, err := apw.ResponseWriter.Write(buf)
return n, err
}
// Hijack implements dns.Hijacker. It simply wraps the underlying
// ResponseWriter's Hijack method if there is one, or returns an error.
func (apw *AutoPathWriter) Hijack() {
func (apw *Writer) Hijack() {
apw.ResponseWriter.Hijack()
return
}
middleware/kubernetes/autopath/cname.go 0 → 100644
View file @ 760e6670
package autopath
import "github.com/miekg/dns"
// CNAME returns a new CNAME formed from name target and ttl.
func CNAME(name string, target string, ttl uint32) *dns.CNAME {
return &dns.CNAME{
Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeCNAME, Class: dns.ClassINET, Ttl: ttl},
Target: dns.Fqdn(target)}
}
middleware/kubernetes/handler.go
View file @ 760e6670
......@@ -5,6 +5,7 @@ import (
"strings"
"github.com/coredns/coredns/middleware"
"github.com/coredns/coredns/middleware/kubernetes/autopath"
"github.com/coredns/coredns/middleware/pkg/dnsutil"
"github.com/coredns/coredns/request"
......@@ -41,14 +42,14 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
records, extra, _, err := k.routeRequest(zone, state)
// Check for Autopath search eligibility
if k.AutoPath.Enabled && k.IsNameError(err) && (state.QType() == dns.TypeA || state.QType() == dns.TypeAAAA) {
if (k.autoPath != nil) && k.IsNameError(err) && (state.QType() == dns.TypeA || state.QType() == dns.TypeAAAA) {
p := k.findPodWithIP(state.IP())
for p != nil {
name, path, ok := splitSearch(zone, state.QName(), p.Namespace)
if !ok {
break
}
if (dns.CountLabel(name) - 1) < k.AutoPath.NDots {
if (dns.CountLabel(name) - 1) < k.autoPath.NDots {
break
}
origQName := state.QName()
......@@ -60,7 +61,7 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
if !k.IsNameError(err) && len(records) > 0 {
records = append(records, nil)
copy(records[1:], records)
records[0] = newCNAME(origQName, records[0].Header().Name, records[0].Header().Ttl)
records[0] = autopath.CNAME(origQName, records[0].Header().Name, records[0].Header().Ttl)
break
}
}
......@@ -68,8 +69,8 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
break
}
// Try host search path (if set) in the next middleware
apw := NewAutoPathWriter(w, r)
for _, hostsearch := range k.AutoPath.HostSearchPath {
apw := autopath.NewWriter(w, r)
for _, hostsearch := range k.autoPath.HostSearchPath {
newstate := state.NewWithQuestion(strings.Join([]string{name, hostsearch}, "."), state.QType())
rcode, nextErr := middleware.NextOrFailure(k.Name(), k.Next, ctx, apw, newstate.Req)
if apw.Sent {
......@@ -82,11 +83,11 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
if !k.IsNameError(err) && len(records) > 0 {
records = append(records, nil)
copy(records[1:], records)
records[0] = newCNAME(origQName, records[0].Header().Name, records[0].Header().Ttl)
records[0] = autopath.CNAME(origQName, records[0].Header().Name, records[0].Header().Ttl)
break
}
// Search . in the next middleware
apw.Rcode = k.AutoPath.OnNXDOMAIN
apw.Rcode = k.autoPath.OnNXDOMAIN
newstate = state.NewWithQuestion(strings.Join([]string{name, "."}, ""), state.QType())
r = newstate.Req
rcode, nextErr := middleware.NextOrFailure(k.Name(), k.Next, ctx, apw, r)
......@@ -125,11 +126,6 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
return dns.RcodeSuccess, nil
}
func newCNAME(name string, target string, ttl uint32) *dns.CNAME {
// TODO factor this out and put in dnsutil
return &dns.CNAME{Hdr: dns.RR_Header{Name: name, Rrtype: dns.TypeCNAME, Class: dns.ClassINET, Ttl: ttl}, Target: dns.Fqdn(target)}
}
func (k *Kubernetes) routeRequest(zone string, state request.Request) (records []dns.RR, extra []dns.RR, debug []dns.RR, err error) {
switch state.Type() {
case "A":
......
middleware/kubernetes/handler_test.go
View file @ 760e6670
......@@ -5,6 +5,7 @@ import (
"sort"
"testing"
"github.com/coredns/coredns/middleware/kubernetes/autopath"
"github.com/coredns/coredns/middleware/pkg/dnsrecorder"
"github.com/coredns/coredns/middleware/test"
......@@ -267,8 +268,8 @@ func TestServeDNS(t *testing.T) {
k.ReverseCidrs = []net.IPNet{*cidr}
k.Federations = []Federation{{name: "fed", zone: "federal.test."}}
k.APIConn = &APIConnServeTest{}
k.AutoPath.Enabled = true
k.AutoPath.HostSearchPath = []string{"hostdom.test"}
k.autoPath = new(autopath.AutoPath)
k.autoPath.HostSearchPath = []string{"hostdom.test"}
k.interfaceAddrsFunc = localPodIP
k.Next = testHandler(nextMWMap)
......@@ -288,11 +289,11 @@ func TestServeDNS(t *testing.T) {
runServeDNSTests(ctx, t, podModeVerifiedCases, k)
// Set ndots to 2 for the ndots test cases
k.AutoPath.NDots = 2
k.autoPath.NDots = 2
runServeDNSTests(ctx, t, autopath2NDotsCases, k)
k.AutoPath.NDots = defautNdots
k.autoPath.NDots = defautNdots
// Disable the NXDOMAIN override (enabled by default)
k.OnNXDOMAIN = dns.RcodeNameError
k.autoPath.OnNXDOMAIN = dns.RcodeNameError
runServeDNSTests(ctx, t, autopathCases, k)
runServeDNSTests(ctx, t, autopathBareSearchExpectNameErr, k)
......
middleware/kubernetes/kubernetes.go
View file @ 760e6670
......@@ -11,6 +11,7 @@ import (
"github.com/coredns/coredns/middleware"
"github.com/coredns/coredns/middleware/etcd/msg"
"github.com/coredns/coredns/middleware/kubernetes/autopath"
"github.com/coredns/coredns/middleware/pkg/dnsutil"
dnsstrings "github.com/coredns/coredns/middleware/pkg/strings"
"github.com/coredns/coredns/middleware/proxy"
......@@ -45,17 +46,9 @@ type Kubernetes struct {
PodMode string
ReverseCidrs []net.IPNet
Fallthrough bool
AutoPath
interfaceAddrsFunc func() net.IP
}
// AutoPath enables server side search path lookups for pods
type AutoPath struct {
Enabled bool
NDots int
ResolvConfFile string
HostSearchPath []string
OnNXDOMAIN int
autoPath *autopath.AutoPath
interfaceAddrsFunc func() net.IP
}
const (
......@@ -259,7 +252,7 @@ func (k *Kubernetes) InitKubeCache() (err error) {
}
opts := dnsControlOpts{
initPodCache: (k.PodMode == PodModeVerified || k.AutoPath.Enabled),
initPodCache: (k.PodMode == PodModeVerified || (k.autoPath != nil)),
}
k.APIConn = newdnsController(kubeClient, k.ResyncPeriod, k.Selector, opts)
......@@ -468,7 +461,7 @@ func (k *Kubernetes) getRecordsForK8sItems(services []service, pods []pod, r rec
}
func (k *Kubernetes) findPodWithIP(ip string) (p *api.Pod) {
if !k.AutoPath.Enabled {
if k.autoPath == nil {
return nil
}
objList := k.APIConn.PodIndex(ip)
......
middleware/kubernetes/setup.go
View file @ 760e6670
......@@ -10,6 +10,7 @@ import (
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/middleware"
"github.com/coredns/coredns/middleware/kubernetes/autopath"
"github.com/coredns/coredns/middleware/pkg/dnsutil"
"github.com/coredns/coredns/middleware/proxy"
"github.com/miekg/dns"
......@@ -192,7 +193,7 @@ func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
return nil, fmt.Errorf("incorrect number of arguments for federation, got %v, expected 2", len(args))
case "autopath": // name zone
args := c.RemainingArgs()
k8s.AutoPath = AutoPath{
k8s.autoPath = &autopath.AutoPath{
NDots: defautNdots,
HostSearchPath: []string{},
ResolvConfFile: defaultResolvConfFile,
......@@ -207,30 +208,29 @@ func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
if err != nil {
return nil, fmt.Errorf("invalid NDOTS argument for autopath, got '%v', expected an integer", ndots)
}
k8s.AutoPath.NDots = ndots
k8s.autoPath.NDots = ndots
}
if len(args) > 1 {
switch args[1] {
case dns.RcodeToString[dns.RcodeNameError]:
k8s.AutoPath.OnNXDOMAIN = dns.RcodeNameError
k8s.autoPath.OnNXDOMAIN = dns.RcodeNameError
case dns.RcodeToString[dns.RcodeSuccess]:
k8s.AutoPath.OnNXDOMAIN = dns.RcodeSuccess
k8s.autoPath.OnNXDOMAIN = dns.RcodeSuccess
case dns.RcodeToString[dns.RcodeServerFailure]:
k8s.AutoPath.OnNXDOMAIN = dns.RcodeServerFailure
k8s.autoPath.OnNXDOMAIN = dns.RcodeServerFailure
default:
return nil, fmt.Errorf("invalid RESPONSE argument for autopath, got '%v', expected SERVFAIL, NOERROR, or NXDOMAIN", args[1])
}
}
if len(args) > 2 {
k8s.AutoPath.ResolvConfFile = args[2]
k8s.autoPath.ResolvConfFile = args[2]
}
rc, err := dns.ClientConfigFromFile(k8s.AutoPath.ResolvConfFile)
rc, err := dns.ClientConfigFromFile(k8s.autoPath.ResolvConfFile)
if err != nil {
return nil, fmt.Errorf("error when parsing %v: %v", k8s.AutoPath.ResolvConfFile, err)
return nil, fmt.Errorf("error when parsing %v: %v", k8s.autoPath.ResolvConfFile, err)
}
k8s.AutoPath.HostSearchPath = rc.Search
middleware.Zones(k8s.AutoPath.HostSearchPath).Normalize()
k8s.AutoPath.Enabled = true
k8s.autoPath.HostSearchPath = rc.Search
middleware.Zones(k8s.autoPath.HostSearchPath).Normalize()
continue
}
}
......
middleware/kubernetes/setup_test.go
View file @ 760e6670
......@@ -8,6 +8,7 @@ import (
"testing"
"time"
"github.com/coredns/coredns/middleware/kubernetes/autopath"
"github.com/coredns/coredns/middleware/test"
"github.com/mholt/caddy"
......@@ -42,7 +43,7 @@ func TestKubernetesParse(t *testing.T) {
expectedFallthrough bool
expectedUpstreams []string
expectedFederations []Federation
expectedAutoPath AutoPath
expectedAutoPath *autopath.AutoPath
}{
// positive
{
......@@ -59,7 +60,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"kubernetes keyword with multiple zones",
......@@ -75,7 +76,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"kubernetes keyword with zone and empty braces",
......@@ -92,7 +93,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"endpoint keyword with url",
......@@ -110,7 +111,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"namespaces keyword with one namespace",
......@@ -128,7 +129,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
nil,
AutoPath{},
nil,
},
{
"namespaces keyword with multiple namespaces",
......@@ -146,7 +147,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"resync period in seconds",
......@@ -164,7 +165,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"resync period in minutes",
......@@ -182,7 +183,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"basic label selector",
......@@ -200,7 +201,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"multi-label selector",
......@@ -218,7 +219,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"fully specified valid config",
......@@ -240,7 +241,7 @@ func TestKubernetesParse(t *testing.T) {
true,
nil,
[]Federation{},
AutoPath{},
nil,
},
// negative
{
......@@ -257,7 +258,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"kubernetes keyword without a zone",
......@@ -273,7 +274,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"endpoint keyword without an endpoint value",
......@@ -291,7 +292,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"namespace keyword without a namespace value",
......@@ -309,7 +310,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"resyncperiod keyword without a duration value",
......@@ -327,7 +328,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"resync period no units",
......@@ -345,7 +346,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"resync period invalid",
......@@ -363,7 +364,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"labels with no selector value",
......@@ -381,7 +382,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
{
"labels with invalid selector value",
......@@ -399,7 +400,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
// pods disabled
{
......@@ -418,7 +419,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
// pods insecure
{
......@@ -437,7 +438,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
// pods verified
{
......@@ -456,7 +457,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
// pods invalid
{
......@@ -475,7 +476,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
// cidrs ok
{
......@@ -494,7 +495,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
// cidrs ok
{
......@@ -513,7 +514,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
// fallthrough invalid
{
......@@ -532,7 +533,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
// Valid upstream
{
......@@ -551,7 +552,7 @@ func TestKubernetesParse(t *testing.T) {
false,
[]string{"13.14.15.16:53"},
[]Federation{},
AutoPath{},
nil,
},
// Invalid upstream
{
......@@ -570,7 +571,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
// Valid federations
{
......@@ -593,7 +594,7 @@ func TestKubernetesParse(t *testing.T) {
{name: "foo", zone: "bar.crawl.com"},
{name: "fed", zone: "era.tion.com"},
},
AutoPath{},
nil,
},
// Invalid federations
{
......@@ -612,7 +613,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
[]Federation{},
AutoPath{},
nil,
},
// autopath
{
......@@ -631,8 +632,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
nil,
AutoPath{
Enabled: true,
&autopath.AutoPath{
NDots: 1,
HostSearchPath: []string{"bar.com.", "baz.com."},
ResolvConfFile: autoPathResolvConfFile,
......@@ -655,7 +655,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
nil,
AutoPath{},
nil,
},
{
"invalid autopath NDOTS",
......@@ -673,7 +673,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
nil,
AutoPath{},
nil,
},
{
"invalid autopath RESOLV-CONF",
......@@ -691,7 +691,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
nil,
AutoPath{},
nil,
},
{
"invalid autopath invalid option",
......@@ -709,7 +709,7 @@ func TestKubernetesParse(t *testing.T) {
false,
nil,
nil,
AutoPath{},
nil,
},
}
......@@ -811,8 +811,8 @@ func TestKubernetesParse(t *testing.T) {
}
}
// autopath
if !reflect.DeepEqual(test.expectedAutoPath, k8sController.AutoPath) {
t.Errorf("Test %d: Expected kubernetes controller to be initialized with autopath '%v'. Instead found autopath '%v' for input '%s'", i, test.expectedAutoPath, k8sController.AutoPath, test.input)
if !reflect.DeepEqual(test.expectedAutoPath, k8sController.autoPath) {
t.Errorf("Test %d: Expected kubernetes controller to be initialized with autopath '%v'. Instead found autopath '%v' for input '%s'", i, test.expectedAutoPath, k8sController.autoPath, test.input)
}
}
}
......
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