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.
2025-10-31 10:13:14 -04:00 · 2016-08-19 17:14:17 -07:00
parent a1989c3523
commit 9ac3cab1b7
140 changed files with 2058 additions and 8229 deletions
--- a/middleware/kubernetes/controller.go
+++ b/middleware/kubernetes/controller.go
@@ -2,7 +2,6 @@ package kubernetes

 import (
 	"fmt"
-	"log"
 	"sync"
 	"time"

@@ -12,7 +11,7 @@ import (
 	"k8s.io/kubernetes/pkg/client/cache"
 	client "k8s.io/kubernetes/pkg/client/unversioned"
 	"k8s.io/kubernetes/pkg/controller/framework"
-    "k8s.io/kubernetes/pkg/labels"
+	"k8s.io/kubernetes/pkg/labels"
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/watch"
 )
@@ -24,7 +23,7 @@ var (
 type dnsController struct {
 	client *client.Client

-    selector *labels.Selector
+	selector *labels.Selector

 	endpController *framework.Controller
 	svcController  *framework.Controller
@@ -45,9 +44,9 @@ type dnsController struct {
 // newDNSController creates a controller for coredns
 func newdnsController(kubeClient *client.Client, resyncPeriod time.Duration, lselector *labels.Selector) *dnsController {
 	dns := dnsController{
-		client: kubeClient,
-        selector: lselector,
-		stopCh: make(chan struct{}),
+		client:   kubeClient,
+		selector: lselector,
+		stopCh:   make(chan struct{}),
 	}

 	dns.endpLister.Store, dns.endpController = framework.NewInformer(
@@ -76,54 +75,54 @@ func newdnsController(kubeClient *client.Client, resyncPeriod time.Duration, lse

 func serviceListFunc(c *client.Client, ns string, s *labels.Selector) func(api.ListOptions) (runtime.Object, error) {
 	return func(opts api.ListOptions) (runtime.Object, error) {
-        if s != nil {
-            opts.LabelSelector = *s
-        }
+		if s != nil {
+			opts.LabelSelector = *s
+		}
 		return c.Services(ns).List(opts)
 	}
 }

 func serviceWatchFunc(c *client.Client, ns string, s *labels.Selector) func(options api.ListOptions) (watch.Interface, error) {
 	return func(options api.ListOptions) (watch.Interface, error) {
-        if s != nil {
-            options.LabelSelector = *s
-        }
+		if s != nil {
+			options.LabelSelector = *s
+		}
 		return c.Services(ns).Watch(options)
 	}
 }

 func endpointsListFunc(c *client.Client, ns string, s *labels.Selector) func(api.ListOptions) (runtime.Object, error) {
 	return func(opts api.ListOptions) (runtime.Object, error) {
-        if s != nil {
-            opts.LabelSelector = *s
-        }
+		if s != nil {
+			opts.LabelSelector = *s
+		}
 		return c.Endpoints(ns).List(opts)
 	}
 }

 func endpointsWatchFunc(c *client.Client, ns string, s *labels.Selector) func(options api.ListOptions) (watch.Interface, error) {
 	return func(options api.ListOptions) (watch.Interface, error) {
-        if s != nil {
-            options.LabelSelector = *s
-        }
+		if s != nil {
+			options.LabelSelector = *s
+		}
 		return c.Endpoints(ns).Watch(options)
 	}
 }

 func namespaceListFunc(c *client.Client, s *labels.Selector) func(api.ListOptions) (runtime.Object, error) {
 	return func(opts api.ListOptions) (runtime.Object, error) {
-        if s != nil {
-            opts.LabelSelector = *s
-        }
+		if s != nil {
+			opts.LabelSelector = *s
+		}
 		return c.Namespaces().List(opts)
 	}
 }

 func namespaceWatchFunc(c *client.Client, s *labels.Selector) func(options api.ListOptions) (watch.Interface, error) {
 	return func(options api.ListOptions) (watch.Interface, error) {
-        if s != nil {
-            options.LabelSelector = *s
-        }
+		if s != nil {
+			options.LabelSelector = *s
+		}
 		return c.Namespaces().Watch(options)
 	}
 }
@@ -140,7 +139,6 @@ func (dns *dnsController) Stop() error {
 	// Only try draining the workqueue if we haven't already.
 	if !dns.shutdown {
 		close(dns.stopCh)
-		log.Println("shutting down controller queues")
 		dns.shutdown = true

 		return nil
@@ -151,14 +149,10 @@ func (dns *dnsController) Stop() error {

 // Run starts the controller.
 func (dns *dnsController) Run() {
-	log.Println("[debug] Starting k8s notification controllers")
-
 	go dns.endpController.Run(dns.stopCh)
 	go dns.svcController.Run(dns.stopCh)
 	go dns.nsController.Run(dns.stopCh)
-
 	<-dns.stopCh
-	log.Println("[debug] shutting down coredns controller")
 }

 func (dns *dnsController) GetNamespaceList() *api.NamespaceList {
@@ -203,12 +197,12 @@ func (dns *dnsController) GetServiceInNamespace(namespace string, servicename st
 	svcObj, svcExists, err := dns.svcLister.Store.GetByKey(svcKey)

 	if err != nil {
-		log.Printf("error getting service %v from the cache: %v\n", svcKey, err)
+		// TODO(...): should return err here
 		return nil
 	}

 	if !svcExists {
-		log.Printf("service %v does not exists\n", svcKey)
+		// TODO(...): should return err here
 		return nil
 	}

--- a/middleware/kubernetes/handler.go
+++ b/middleware/kubernetes/handler.go
@@ -2,7 +2,6 @@ package kubernetes

 import (
 	"fmt"
-	"log"
 	"strings"

 	"github.com/miekg/coredns/middleware"
@@ -12,8 +11,6 @@ import (
 )

 func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
-	log.Printf("[debug] here entering ServeDNS: ctx:%v dnsmsg:%v\n", ctx, r)
-
 	state := middleware.State{W: w, Req: r}
 	if state.QClass() != dns.ClassINET {
 		return dns.RcodeServerFailure, fmt.Errorf("can only deal with ClassINET")
--- a/middleware/kubernetes/kubernetes.go
+++ b/middleware/kubernetes/kubernetes.go
@@ -16,10 +16,10 @@ import (
 	"github.com/miekg/dns"
 	"k8s.io/kubernetes/pkg/api"
 	unversionedapi "k8s.io/kubernetes/pkg/api/unversioned"
-	"k8s.io/kubernetes/pkg/labels"
 	unversionedclient "k8s.io/kubernetes/pkg/client/unversioned"
 	"k8s.io/kubernetes/pkg/client/unversioned/clientcmd"
 	clientcmdapi "k8s.io/kubernetes/pkg/client/unversioned/clientcmd/api"
+	"k8s.io/kubernetes/pkg/labels"
 )

 type Kubernetes struct {
@@ -32,10 +32,10 @@ type Kubernetes struct {
 	NameTemplate  *nametemplate.NameTemplate
 	Namespaces    []string
 	LabelSelector *unversionedapi.LabelSelector
-	Selector      *labels.Selector 
+	Selector      *labels.Selector
 }

-func (g *Kubernetes) StartKubeCache() error {
+func (g *Kubernetes) InitKubeCache() error {
 	// For a custom api server or running outside a k8s cluster
 	// set URL in env.KUBERNETES_MASTER or set endpoint in Corefile
 	loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
@@ -46,7 +46,6 @@ func (g *Kubernetes) StartKubeCache() error {
 	clientConfig := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, overrides)
 	config, err := clientConfig.ClientConfig()
 	if err != nil {
-		log.Printf("[debug] error connecting to the client: %v", err)
 		return err
 	}
 	kubeClient, err := unversionedclient.New(config)
@@ -58,20 +57,17 @@ func (g *Kubernetes) StartKubeCache() error {
 	if g.LabelSelector == nil {
 		log.Printf("[INFO] Kubernetes middleware configured without a label selector. No label-based filtering will be performed.")
 	} else {
-        var selector labels.Selector
+		var selector labels.Selector
 		selector, err = unversionedapi.LabelSelectorAsSelector(g.LabelSelector)
-        g.Selector = &selector
-        if err != nil {
-            log.Printf("[ERROR] Unable to create Selector for LabelSelector '%s'.Error was: %s", g.LabelSelector, err)
-            return err
-        }
+		g.Selector = &selector
+		if err != nil {
+			log.Printf("[ERROR] Unable to create Selector for LabelSelector '%s'.Error was: %s", g.LabelSelector, err)
+			return err
+		}
 		log.Printf("[INFO] Kubernetes middleware configured with the label selector '%s'. Only kubernetes objects matching this label selector will be exposed.", unversionedapi.FormatLabelSelector(g.LabelSelector))
 	}
-	log.Printf("[debug] Starting kubernetes middleware with k8s API resync period: %s", g.ResyncPeriod)
 	g.APIConn = newdnsController(kubeClient, g.ResyncPeriod, g.Selector)

-	go g.APIConn.Run()
-
 	return err
 }

@@ -115,7 +111,6 @@ func (g *Kubernetes) Records(name string, exact bool) ([]msg.Service, error) {
 		typeName    string
 	)

-	log.Printf("[debug] enter Records('%v', '%v')\n", name, exact)
 	zone, serviceSegments := g.getZoneForName(name)

 	// TODO: Implementation above globbed together segments for the serviceName if
@@ -137,30 +132,18 @@ func (g *Kubernetes) Records(name string, exact bool) ([]msg.Service, error) {
 		serviceName = util.WildcardStar
 	}

-	log.Printf("[debug] published namespaces: %v\n", g.Namespaces)
-
-	log.Printf("[debug] exact: %v\n", exact)
-	log.Printf("[debug] zone: %v\n", zone)
-	log.Printf("[debug] servicename: %v\n", serviceName)
-	log.Printf("[debug] namespace: %v\n", namespace)
-	log.Printf("[debug] typeName: %v\n", typeName)
-	log.Printf("[debug] APIconn: %v\n", g.APIConn)
-
 	nsWildcard := util.SymbolContainsWildcard(namespace)
 	serviceWildcard := util.SymbolContainsWildcard(serviceName)

 	// Abort if the namespace does not contain a wildcard, and namespace is not published per CoreFile
 	// Case where namespace contains a wildcard is handled in Get(...) method.
 	if (!nsWildcard) && (len(g.Namespaces) > 0) && (!util.StringInSlice(namespace, g.Namespaces)) {
-		log.Printf("[debug] Namespace '%v' is not published by Corefile\n", namespace)
 		return nil, nil
 	}

-	log.Printf("before g.Get(namespace, nsWildcard, serviceName, serviceWildcard): %v %v %v %v", namespace, nsWildcard, serviceName, serviceWildcard)
+	log.Printf("[debug] before g.Get(namespace, nsWildcard, serviceName, serviceWildcard): %v %v %v %v", namespace, nsWildcard, serviceName, serviceWildcard)
 	k8sItems, err := g.Get(namespace, nsWildcard, serviceName, serviceWildcard)
-	log.Printf("[debug] k8s items: %v\n", k8sItems)
 	if err != nil {
-		log.Printf("[ERROR] Got error while looking up ServiceItems. Error is: %v\n", err)
 		return nil, err
 	}
 	if k8sItems == nil {
@@ -178,7 +161,6 @@ func (g *Kubernetes) getRecordsForServiceItems(serviceItems []api.Service, value

 	for _, item := range serviceItems {
 		clusterIP := item.Spec.ClusterIP
-		log.Printf("[debug] clusterIP: %v\n", clusterIP)

 		// Create records by constructing record name from template...
 		//values.Namespace = item.Metadata.Namespace
@@ -188,13 +170,11 @@ func (g *Kubernetes) getRecordsForServiceItems(serviceItems []api.Service, value

 		// Create records for each exposed port...
 		for _, p := range item.Spec.Ports {
-			log.Printf("[debug]    port: %v\n", p.Port)
 			s := msg.Service{Host: clusterIP, Port: int(p.Port)}
 			records = append(records, s)
 		}
 	}

-	log.Printf("[debug] records from getRecordsForServiceItems(): %v\n", records)
 	return records
 }

@@ -202,13 +182,6 @@ func (g *Kubernetes) getRecordsForServiceItems(serviceItems []api.Service, value
 func (g *Kubernetes) Get(namespace string, nsWildcard bool, servicename string, serviceWildcard bool) ([]api.Service, error) {
 	serviceList := g.APIConn.GetServiceList()

-	/* TODO: Remove?
-	if err != nil {
-		log.Printf("[ERROR] Getting service list produced error: %v", err)
-		return nil, err
-	}
-	*/
-
 	var resultItems []api.Service

 	for _, item := range serviceList.Items {
@@ -216,7 +189,6 @@ func (g *Kubernetes) Get(namespace string, nsWildcard bool, servicename string,
 			// If namespace has a wildcard, filter results against Corefile namespace list.
 			// (Namespaces without a wildcard were filtered before the call to this function.)
 			if nsWildcard && (len(g.Namespaces) > 0) && (!util.StringInSlice(item.Namespace, g.Namespaces)) {
-				log.Printf("[debug] Namespace '%v' is not published by Corefile\n", item.Namespace)
 				continue
 			}
 			resultItems = append(resultItems, item)
--- a/middleware/kubernetes/nametemplate/nametemplate.go
+++ b/middleware/kubernetes/nametemplate/nametemplate.go
@@ -2,7 +2,6 @@ package nametemplate

 import (
 	"errors"
-	"log"
 	"strings"

 	"github.com/miekg/coredns/middleware/kubernetes/util"
@@ -87,17 +86,13 @@ func (t *NameTemplate) SetTemplate(s string) error {
 		if !elementPositionSet {
 			if strings.Contains(v, "{") {
 				err = errors.New("Record name template contains the unknown symbol '" + v + "'")
-				log.Printf("[debug] %v\n", err)
 				return err
-			} else {
-				log.Printf("[debug] Template string has static element '%v'\n", v)
 			}
 		}
 	}

 	if err == nil && !t.IsValid() {
 		err = errors.New("Record name template does not pass NameTemplate validation")
-		log.Printf("[debug] %v\n", err)
 		return err
 	}

--- a/middleware/kubernetes/setup.go
+++ b/middleware/kubernetes/setup.go
@@ -0,0 +1,140 @@
+package kubernetes
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/miekg/coredns/core/dnsserver"
+	"github.com/miekg/coredns/middleware"
+	"github.com/miekg/coredns/middleware/kubernetes/nametemplate"
+
+	"github.com/mholt/caddy"
+	unversionedapi "k8s.io/kubernetes/pkg/api/unversioned"
+)
+
+func init() {
+	caddy.RegisterPlugin("kubernetes", caddy.Plugin{
+		ServerType: "dns",
+		Action:     setup,
+	})
+}
+
+func setup(c *caddy.Controller) error {
+	kubernetes, err := kubernetesParse(c)
+	if err != nil {
+		return err
+	}
+
+	err = kubernetes.InitKubeCache()
+	if err != nil {
+		return err
+	}
+
+	// Register KubeCache start and stop functions with Caddy
+	c.OnStartup(func() error {
+		go kubernetes.APIConn.Run()
+		return nil
+	})
+
+	c.OnShutdown(func() error {
+		return kubernetes.APIConn.Stop()
+	})
+
+	dnsserver.GetConfig(c).AddMiddleware(func(next dnsserver.Handler) dnsserver.Handler {
+		kubernetes.Next = next
+		return kubernetes
+	})
+
+	return nil
+}
+
+func kubernetesParse(c *caddy.Controller) (Kubernetes, error) {
+	var err error
+	template := defaultNameTemplate
+
+	k8s := Kubernetes{ResyncPeriod: defaultResyncPeriod}
+	k8s.NameTemplate = new(nametemplate.NameTemplate)
+	k8s.NameTemplate.SetTemplate(template)
+
+	for c.Next() {
+		if c.Val() == "kubernetes" {
+			zones := c.RemainingArgs()
+
+			if len(zones) == 0 {
+				k8s.Zones = make([]string, len(c.ServerBlockKeys))
+				copy(k8s.Zones, c.ServerBlockKeys)
+			}
+
+			k8s.Zones = NormalizeZoneList(zones)
+			middleware.Zones(k8s.Zones).FullyQualify()
+
+			if k8s.Zones == nil || len(k8s.Zones) < 1 {
+				err = errors.New("Zone name must be provided for kubernetes middleware.")
+				return Kubernetes{}, err
+			}
+
+			for c.NextBlock() {
+				switch c.Val() {
+				case "template":
+					args := c.RemainingArgs()
+					if len(args) != 0 {
+						template := strings.Join(args, "")
+						err = k8s.NameTemplate.SetTemplate(template)
+						if err != nil {
+							return Kubernetes{}, err
+						}
+					} else {
+						return Kubernetes{}, c.ArgErr()
+					}
+				case "namespaces":
+					args := c.RemainingArgs()
+					if len(args) != 0 {
+						k8s.Namespaces = append(k8s.Namespaces, args...)
+					} else {
+						return Kubernetes{}, c.ArgErr()
+					}
+				case "endpoint":
+					args := c.RemainingArgs()
+					if len(args) != 0 {
+						k8s.APIEndpoint = args[0]
+					} else {
+						return Kubernetes{}, c.ArgErr()
+					}
+				case "resyncperiod":
+					args := c.RemainingArgs()
+					if len(args) != 0 {
+						k8s.ResyncPeriod, err = time.ParseDuration(args[0])
+						if err != nil {
+							err = errors.New(fmt.Sprintf("Unable to parse resync duration value. Value provided was '%v'. Example valid values: '15s', '5m', '1h'. Error was: %v", args[0], err))
+							return Kubernetes{}, err
+						}
+					} else {
+						return Kubernetes{}, c.ArgErr()
+					}
+				case "labels":
+					args := c.RemainingArgs()
+					if len(args) != 0 {
+						labelSelectorString := strings.Join(args, " ")
+						k8s.LabelSelector, err = unversionedapi.ParseToLabelSelector(labelSelectorString)
+						if err != nil {
+							err = errors.New(fmt.Sprintf("Unable to parse label selector. Value provided was '%v'. Error was: %v", labelSelectorString, err))
+							return Kubernetes{}, err
+						}
+					} else {
+						return Kubernetes{}, c.ArgErr()
+					}
+				}
+			}
+			return k8s, nil
+		}
+	}
+	err = errors.New("Kubernetes setup called without keyword 'kubernetes' in Corefile")
+	return Kubernetes{}, err
+}
+
+const (
+	defaultNameTemplate = "{service}.{namespace}.{zone}"
+	defaultResyncPeriod = 5 * time.Minute
+)
--- a/middleware/kubernetes/setup_test.go
+++ b/middleware/kubernetes/setup_test.go
@@ -0,0 +1,390 @@
+package kubernetes
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/mholt/caddy"
+	unversionedapi "k8s.io/kubernetes/pkg/api/unversioned"
+)
+
+func TestKubernetesParse(t *testing.T) {
+	tests := []struct {
+		description           string        // Human-facing description of test case
+		input                 string        // Corefile data as string
+		shouldErr             bool          // true if test case is exected to produce an error.
+		expectedErrContent    string        // substring from the expected error. Empty for positive cases.
+		expectedZoneCount     int           // expected count of defined zones.
+		expectedNTValid       bool          // NameTemplate to be initialized and valid
+		expectedNSCount       int           // expected count of namespaces.
+		expectedResyncPeriod  time.Duration // expected resync period value
+		expectedLabelSelector string        // expected label selector value
+	}{
+		// positive
+		{
+			"kubernetes keyword with one zone",
+			`kubernetes coredns.local`,
+			false,
+			"",
+			1,
+			true,
+			0,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"kubernetes keyword with multiple zones",
+			`kubernetes coredns.local test.local`,
+			false,
+			"",
+			2,
+			true,
+			0,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"kubernetes keyword with zone and empty braces",
+			`kubernetes coredns.local {
+}`,
+			false,
+			"",
+			1,
+			true,
+			0,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"endpoint keyword with url",
+			`kubernetes coredns.local {
+	endpoint http://localhost:9090
+}`,
+			false,
+			"",
+			1,
+			true,
+			0,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"template keyword with valid template",
+			`kubernetes coredns.local {
+	template {service}.{namespace}.{zone}
+}`,
+			false,
+			"",
+			1,
+			true,
+			0,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"namespaces keyword with one namespace",
+			`kubernetes coredns.local {
+	namespaces demo
+}`,
+			false,
+			"",
+			1,
+			true,
+			1,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"namespaces keyword with multiple namespaces",
+			`kubernetes coredns.local {
+	namespaces demo test
+}`,
+			false,
+			"",
+			1,
+			true,
+			2,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"resync period in seconds",
+			`kubernetes coredns.local {
+    resyncperiod 30s
+}`,
+			false,
+			"",
+			1,
+			true,
+			0,
+			30 * time.Second,
+			"",
+		},
+		{
+			"resync period in minutes",
+			`kubernetes coredns.local {
+    resyncperiod 15m
+}`,
+			false,
+			"",
+			1,
+			true,
+			0,
+			15 * time.Minute,
+			"",
+		},
+		{
+			"basic label selector",
+			`kubernetes coredns.local {
+    labels environment=prod
+}`,
+			false,
+			"",
+			1,
+			true,
+			0,
+			defaultResyncPeriod,
+			"environment=prod",
+		},
+		{
+			"multi-label selector",
+			`kubernetes coredns.local {
+    labels environment in (production, staging, qa),application=nginx
+}`,
+			false,
+			"",
+			1,
+			true,
+			0,
+			defaultResyncPeriod,
+			"application=nginx,environment in (production,qa,staging)",
+		},
+		{
+			"fully specified valid config",
+			`kubernetes coredns.local test.local {
+    resyncperiod 15m
+	endpoint http://localhost:8080
+	template {service}.{namespace}.{zone}
+	namespaces demo test
+    labels environment in (production, staging, qa),application=nginx
+}`,
+			false,
+			"",
+			2,
+			true,
+			2,
+			15 * time.Minute,
+			"application=nginx,environment in (production,qa,staging)",
+		},
+		// negative
+		{
+			"no kubernetes keyword",
+			"",
+			true,
+			"Kubernetes setup called without keyword 'kubernetes' in Corefile",
+			-1,
+			false,
+			-1,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"kubernetes keyword without a zone",
+			`kubernetes`,
+			true,
+			"Zone name must be provided for kubernetes middleware",
+			-1,
+			true,
+			0,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"endpoint keyword without an endpoint value",
+			`kubernetes coredns.local {
+    endpoint
+}`,
+			true,
+			"Wrong argument count or unexpected line ending after 'endpoint'",
+			-1,
+			true,
+			-1,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"template keyword without a template value",
+			`kubernetes coredns.local {
+    template
+}`,
+			true,
+			"Wrong argument count or unexpected line ending after 'template'",
+			-1,
+			false,
+			0,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"template keyword with an invalid template value",
+			`kubernetes coredns.local {
+    template {namespace}.{zone}
+}`,
+			true,
+			"Record name template does not pass NameTemplate validation",
+			-1,
+			false,
+			0,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"namespace keyword without a namespace value",
+			`kubernetes coredns.local {
+	namespaces
+}`,
+			true,
+			"Parse error: Wrong argument count or unexpected line ending after 'namespaces'",
+			-1,
+			true,
+			-1,
+			defaultResyncPeriod,
+			"",
+		},
+		{
+			"resyncperiod keyword without a duration value",
+			`kubernetes coredns.local {
+    resyncperiod
+}`,
+			true,
+			"Wrong argument count or unexpected line ending after 'resyncperiod'",
+			-1,
+			true,
+			0,
+			0 * time.Minute,
+			"",
+		},
+		{
+			"resync period no units",
+			`kubernetes coredns.local {
+    resyncperiod 15
+}`,
+			true,
+			"Unable to parse resync duration value. Value provided was ",
+			-1,
+			true,
+			0,
+			0 * time.Second,
+			"",
+		},
+		{
+			"resync period invalid",
+			`kubernetes coredns.local {
+    resyncperiod abc
+}`,
+			true,
+			"Unable to parse resync duration value. Value provided was ",
+			-1,
+			true,
+			0,
+			0 * time.Second,
+			"",
+		},
+		{
+			"labels with no selector value",
+			`kubernetes coredns.local {
+    labels
+}`,
+			true,
+			"Wrong argument count or unexpected line ending after 'labels'",
+			-1,
+			true,
+			0,
+			0 * time.Second,
+			"",
+		},
+		{
+			"labels with invalid selector value",
+			`kubernetes coredns.local {
+    labels environment in (production, qa
+}`,
+			true,
+			"Unable to parse label selector. Value provided was",
+			-1,
+			true,
+			0,
+			0 * time.Second,
+			"",
+		},
+	}
+
+	t.Logf("Parser test cases count: %v", len(tests))
+	for i, test := range tests {
+		c := caddy.NewTestController("dns", test.input)
+		k8sController, err := kubernetesParse(c)
+		t.Logf("setup test: %2v -- %v\n", i, test.description)
+		//t.Logf("controller: %v\n", k8sController)
+
+		if test.shouldErr && err == nil {
+			t.Errorf("Test %d: Expected error, but did not find error for input '%s'. Error was: '%v'", i, test.input, err)
+		}
+
+		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)
+				continue
+			}
+
+			if test.shouldErr && (len(test.expectedErrContent) < 1) {
+				t.Fatalf("Test %d: Test marked as expecting an error, but no expectedErrContent provided for input '%s'. Error was: '%v'", i, test.input, err)
+			}
+
+			if test.shouldErr && (test.expectedZoneCount >= 0) {
+				t.Errorf("Test %d: Test marked as expecting an error, but provides value for expectedZoneCount!=-1 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)
+			}
+			continue
+		}
+
+		// No error was raised, so validate initialization of k8sController
+		//     Zones
+		foundZoneCount := len(k8sController.Zones)
+		if foundZoneCount != test.expectedZoneCount {
+			t.Errorf("Test %d: Expected kubernetes controller to be initialized with %d zones, instead found %d zones: '%v' for input '%s'", i, test.expectedZoneCount, foundZoneCount, k8sController.Zones, test.input)
+		}
+
+		//    NameTemplate
+		if k8sController.NameTemplate == nil {
+			t.Errorf("Test %d: Expected kubernetes controller to be initialized with a NameTemplate. Instead found '%v' for input '%s'", i, k8sController.NameTemplate, test.input)
+		} else {
+			foundNTValid := k8sController.NameTemplate.IsValid()
+			if foundNTValid != test.expectedNTValid {
+				t.Errorf("Test %d: Expected NameTemplate validity to be '%v', instead found '%v' for input '%s'", i, test.expectedNTValid, foundNTValid, test.input)
+			}
+		}
+
+		//    Namespaces
+		foundNSCount := len(k8sController.Namespaces)
+		if foundNSCount != test.expectedNSCount {
+			t.Errorf("Test %d: Expected kubernetes controller to be initialized with %d namespaces. Instead found %d namespaces: '%v' for input '%s'", i, test.expectedNSCount, foundNSCount, k8sController.Namespaces, test.input)
+		}
+
+		//    ResyncPeriod
+		foundResyncPeriod := k8sController.ResyncPeriod
+		if foundResyncPeriod != test.expectedResyncPeriod {
+			t.Errorf("Test %d: Expected kubernetes controller to be initialized with resync period '%s'. Instead found period '%s' for input '%s'", i, test.expectedResyncPeriod, foundResyncPeriod, test.input)
+		}
+
+		//    Labels
+		if k8sController.LabelSelector != nil {
+			foundLabelSelectorString := unversionedapi.FormatLabelSelector(k8sController.LabelSelector)
+			if foundLabelSelectorString != test.expectedLabelSelector {
+				t.Errorf("Test %d: Expected kubernetes controller to be initialized with label selector '%s'. Instead found selector '%s' for input '%s'", i, test.expectedLabelSelector, foundLabelSelectorString, test.input)
+			}
+		}
+	}
+}