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

1 files changed, 82 insertions, 0 deletions

diff --git a/plugin/dnssec/handler.go b/plugin/dnssec/handler.go
new file mode 100644
index 000000000..6fa2dd042
--- /dev/null
+++ b/plugin/dnssec/handler.go
@@ -0,0 +1,82 @@
+package dnssec
+
+import (
+	"github.com/coredns/coredns/plugin"
+	"github.com/coredns/coredns/request"
+
+	"github.com/miekg/dns"
+	"github.com/prometheus/client_golang/prometheus"
+	"golang.org/x/net/context"
+)
+
+// ServeDNS implements the plugin.Handler interface.
+func (d Dnssec) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
+	state := request.Request{W: w, Req: r}
+
+	do := state.Do()
+	qname := state.Name()
+	qtype := state.QType()
+	zone := plugin.Zones(d.zones).Matches(qname)
+	if zone == "" {
+		return plugin.NextOrFailure(d.Name(), d.Next, ctx, w, r)
+	}
+
+	// Intercept queries for DNSKEY, but only if one of the zones matches the qname, otherwise we let
+	// the query through.
+	if qtype == dns.TypeDNSKEY {
+		for _, z := range d.zones {
+			if qname == z {
+				resp := d.getDNSKEY(state, z, do)
+				resp.Authoritative = true
+				state.SizeAndDo(resp)
+				w.WriteMsg(resp)
+				return dns.RcodeSuccess, nil
+			}
+		}
+	}
+
+	drr := &ResponseWriter{w, d}
+	return plugin.NextOrFailure(d.Name(), d.Next, ctx, drr, r)
+}
+
+var (
+	cacheSize = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: plugin.Namespace,
+		Subsystem: subsystem,
+		Name:      "cache_size",
+		Help:      "The number of elements in the dnssec cache.",
+	}, []string{"type"})
+
+	cacheCapacity = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: plugin.Namespace,
+		Subsystem: subsystem,
+		Name:      "cache_capacity",
+		Help:      "The dnssec cache's capacity.",
+	}, []string{"type"})
+
+	cacheHits = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: plugin.Namespace,
+		Subsystem: subsystem,
+		Name:      "cache_hits_total",
+		Help:      "The count of cache hits.",
+	})
+
+	cacheMisses = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: plugin.Namespace,
+		Subsystem: subsystem,
+		Name:      "cache_misses_total",
+		Help:      "The count of cache misses.",
+	})
+)
+
+// Name implements the Handler interface.
+func (d Dnssec) Name() string { return "dnssec" }
+
+const subsystem = "dnssec"
+
+func init() {
+	prometheus.MustRegister(cacheSize)
+	prometheus.MustRegister(cacheCapacity)
+	prometheus.MustRegister(cacheHits)
+	prometheus.MustRegister(cacheMisses)
+}