Remove the word middleware (#1067)

* Rename middleware to plugin

first pass; mostly used 'sed', few spots where I manually changed
text.

This still builds a coredns binary.

* fmt error

* Rename AddMiddleware to AddPlugin

* Readd AddMiddleware to remain backwards compat

plugin/kubernetes/setup.go

@@ -0,0 +1,208 @@
+package kubernetes
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/coredns/coredns/core/dnsserver"
+	"github.com/coredns/coredns/plugin"
+	"github.com/coredns/coredns/plugin/pkg/dnsutil"
+	"github.com/coredns/coredns/plugin/proxy"
+	"github.com/miekg/dns"
+
+	"github.com/mholt/caddy"
+	unversionedapi "k8s.io/client-go/1.5/pkg/api/unversioned"
+)
+
+func init() {
+	caddy.RegisterPlugin("kubernetes", caddy.Plugin{
+		ServerType: "dns",
+		Action:     setup,
+	})
+}
+
+func setup(c *caddy.Controller) error {
+	kubernetes, initOpts, err := kubernetesParse(c)
+	if err != nil {
+		return plugin.Error("kubernetes", err)
+	}
+
+	err = kubernetes.initKubeCache(initOpts)
+	if err != nil {
+		return plugin.Error("kubernetes", err)
+	}
+
+	// Register KubeCache start and stop functions with Caddy
+	c.OnStartup(func() error {
+		go kubernetes.APIConn.Run()
+		if kubernetes.APIProxy != nil {
+			go kubernetes.APIProxy.Run()
+		}
+		return nil
+	})
+
+	c.OnShutdown(func() error {
+		if kubernetes.APIProxy != nil {
+			kubernetes.APIProxy.Stop()
+		}
+		return kubernetes.APIConn.Stop()
+	})
+
+	dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
+		kubernetes.Next = next
+		return kubernetes
+	})
+
+	return nil
+}
+
+func kubernetesParse(c *caddy.Controller) (*Kubernetes, dnsControlOpts, error) {
+	k8s := New([]string{""})
+	k8s.interfaceAddrsFunc = localPodIP
+	k8s.autoPathSearch = searchFromResolvConf()
+
+	opts := dnsControlOpts{
+		resyncPeriod: defaultResyncPeriod,
+	}
+
+	for c.Next() {
+		zones := c.RemainingArgs()
+
+		if len(zones) != 0 {
+			k8s.Zones = zones
+			for i := 0; i < len(k8s.Zones); i++ {
+				k8s.Zones[i] = plugin.Host(k8s.Zones[i]).Normalize()
+			}
+		} else {
+			k8s.Zones = make([]string, len(c.ServerBlockKeys))
+			for i := 0; i < len(c.ServerBlockKeys); i++ {
+				k8s.Zones[i] = plugin.Host(c.ServerBlockKeys[i]).Normalize()
+			}
+		}
+
+		k8s.primaryZoneIndex = -1
+		for i, z := range k8s.Zones {
+			if strings.HasSuffix(z, "in-addr.arpa.") || strings.HasSuffix(z, "ip6.arpa.") {
+				continue
+			}
+			k8s.primaryZoneIndex = i
+			break
+		}
+
+		if k8s.primaryZoneIndex == -1 {
+			return nil, opts, errors.New("non-reverse zone name must be used")
+		}
+
+		for c.NextBlock() {
+			switch c.Val() {
+			case "pods":
+				args := c.RemainingArgs()
+				if len(args) == 1 {
+					switch args[0] {
+					case podModeDisabled, podModeInsecure, podModeVerified:
+						k8s.podMode = args[0]
+					default:
+						return nil, opts, fmt.Errorf("wrong value for pods: %s,  must be one of: disabled, verified, insecure", args[0])
+					}
+					continue
+				}
+				return nil, opts, c.ArgErr()
+			case "namespaces":
+				args := c.RemainingArgs()
+				if len(args) > 0 {
+					for _, a := range args {
+						k8s.Namespaces[a] = true
+					}
+					continue
+				}
+				return nil, opts, c.ArgErr()
+			case "endpoint":
+				args := c.RemainingArgs()
+				if len(args) > 0 {
+					for _, endpoint := range strings.Split(args[0], ",") {
+						k8s.APIServerList = append(k8s.APIServerList, strings.TrimSpace(endpoint))
+					}
+					continue
+				}
+				return nil, opts, c.ArgErr()
+			case "tls": // cert key cacertfile
+				args := c.RemainingArgs()
+				if len(args) == 3 {
+					k8s.APIClientCert, k8s.APIClientKey, k8s.APICertAuth = args[0], args[1], args[2]
+					continue
+				}
+				return nil, opts, c.ArgErr()
+			case "resyncperiod":
+				args := c.RemainingArgs()
+				if len(args) > 0 {
+					rp, err := time.ParseDuration(args[0])
+					if err != nil {
+						return nil, opts, fmt.Errorf("unable to parse resync duration value: '%v': %v", args[0], err)
+					}
+					opts.resyncPeriod = rp
+					continue
+				}
+				return nil, opts, c.ArgErr()
+			case "labels":
+				args := c.RemainingArgs()
+				if len(args) > 0 {
+					labelSelectorString := strings.Join(args, " ")
+					ls, err := unversionedapi.ParseToLabelSelector(labelSelectorString)
+					if err != nil {
+						return nil, opts, fmt.Errorf("unable to parse label selector value: '%v': %v", labelSelectorString, err)
+					}
+					opts.labelSelector = ls
+					continue
+				}
+				return nil, opts, c.ArgErr()
+			case "fallthrough":
+				args := c.RemainingArgs()
+				if len(args) == 0 {
+					k8s.Fallthrough = true
+					continue
+				}
+				return nil, opts, c.ArgErr()
+			case "upstream":
+				args := c.RemainingArgs()
+				if len(args) == 0 {
+					return nil, opts, c.ArgErr()
+				}
+				ups, err := dnsutil.ParseHostPortOrFile(args...)
+				if err != nil {
+					return nil, opts, err
+				}
+				k8s.Proxy = proxy.NewLookup(ups)
+			case "ttl":
+				args := c.RemainingArgs()
+				if len(args) == 0 {
+					return nil, opts, c.ArgErr()
+				}
+				t, err := strconv.Atoi(args[0])
+				if err != nil {
+					return nil, opts, err
+				}
+				if t < 5 || t > 3600 {
+					return nil, opts, c.Errf("ttl must be in range [5, 3600]: %d", t)
+				}
+				k8s.ttl = uint32(t)
+			default:
+				return nil, opts, c.Errf("unknown property '%s'", c.Val())
+			}
+		}
+	}
+	return k8s, opts, nil
+}
+
+func searchFromResolvConf() []string {
+	rc, err := dns.ClientConfigFromFile("/etc/resolv.conf")
+	if err != nil {
+		return nil
+	}
+	plugin.Zones(rc.Search).Normalize()
+	return rc.Search
+}
+
+const defaultResyncPeriod = 5 * time.Minute