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

2 files changed, 0 insertions, 131 deletions

diff --git a/middleware/metrics/vars/report.go b/middleware/metrics/vars/report.go
deleted file mode 100644
index 5d8f2ba64..000000000
--- a/middleware/metrics/vars/report.go
+++ /dev/null
@@ -1,62 +0,0 @@
-package vars
-
-import (
-	"time"
-
-	"github.com/coredns/coredns/request"
-
-	"github.com/miekg/dns"
-)
-
-// Report reports the metrics data associcated with request.
-func Report(req request.Request, zone, rcode string, size int, start time.Time) {
-	// Proto and Family.
-	net := req.Proto()
-	fam := "1"
-	if req.Family() == 2 {
-		fam = "2"
-	}
-
-	typ := req.QType()
-
-	RequestCount.WithLabelValues(zone, net, fam).Inc()
-	RequestDuration.WithLabelValues(zone).Observe(float64(time.Since(start) / time.Millisecond))
-
-	if req.Do() {
-		RequestDo.WithLabelValues(zone).Inc()
-	}
-
-	if _, known := monitorType[typ]; known {
-		RequestType.WithLabelValues(zone, dns.Type(typ).String()).Inc()
-	} else {
-		RequestType.WithLabelValues(zone, other).Inc()
-	}
-
-	ResponseSize.WithLabelValues(zone, net).Observe(float64(size))
-	RequestSize.WithLabelValues(zone, net).Observe(float64(req.Len()))
-
-	ResponseRcode.WithLabelValues(zone, rcode).Inc()
-}
-
-var monitorType = map[uint16]bool{
-	dns.TypeAAAA:   true,
-	dns.TypeA:      true,
-	dns.TypeCNAME:  true,
-	dns.TypeDNSKEY: true,
-	dns.TypeDS:     true,
-	dns.TypeMX:     true,
-	dns.TypeNSEC3:  true,
-	dns.TypeNSEC:   true,
-	dns.TypeNS:     true,
-	dns.TypePTR:    true,
-	dns.TypeRRSIG:  true,
-	dns.TypeSOA:    true,
-	dns.TypeSRV:    true,
-	dns.TypeTXT:    true,
-	// Meta Qtypes
-	dns.TypeIXFR: true,
-	dns.TypeAXFR: true,
-	dns.TypeANY:  true,
-}
-
-const other = "other"
diff --git a/middleware/metrics/vars/vars.go b/middleware/metrics/vars/vars.go
deleted file mode 100644
index 42af10007..000000000
--- a/middleware/metrics/vars/vars.go
+++ /dev/null
@@ -1,69 +0,0 @@
-package vars
-
-import (
-	"github.com/coredns/coredns/middleware"
-
-	"github.com/prometheus/client_golang/prometheus"
-)
-
-// Request* and Response* are the prometheus counters and gauges we are using for exporting metrics.
-var (
-	RequestCount = prometheus.NewCounterVec(prometheus.CounterOpts{
-		Namespace: middleware.Namespace,
-		Subsystem: subsystem,
-		Name:      "request_count_total",
-		Help:      "Counter of DNS requests made per zone, protocol and family.",
-	}, []string{"zone", "proto", "family"})
-
-	RequestDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
-		Namespace: middleware.Namespace,
-		Subsystem: subsystem,
-		Name:      "request_duration_milliseconds",
-		Buckets:   append(prometheus.DefBuckets, []float64{50, 100, 200, 500, 1000, 2000, 3000, 4000, 5000, 10000}...),
-		Help:      "Histogram of the time (in milliseconds) each request took.",
-	}, []string{"zone"})
-
-	RequestSize = prometheus.NewHistogramVec(prometheus.HistogramOpts{
-		Namespace: middleware.Namespace,
-		Subsystem: subsystem,
-		Name:      "request_size_bytes",
-		Help:      "Size of the EDNS0 UDP buffer in bytes (64K for TCP).",
-		Buckets:   []float64{0, 100, 200, 300, 400, 511, 1023, 2047, 4095, 8291, 16e3, 32e3, 48e3, 64e3},
-	}, []string{"zone", "proto"})
-
-	RequestDo = prometheus.NewCounterVec(prometheus.CounterOpts{
-		Namespace: middleware.Namespace,
-		Subsystem: subsystem,
-		Name:      "request_do_count_total",
-		Help:      "Counter of DNS requests with DO bit set per zone.",
-	}, []string{"zone"})
-
-	RequestType = prometheus.NewCounterVec(prometheus.CounterOpts{
-		Namespace: middleware.Namespace,
-		Subsystem: subsystem,
-		Name:      "request_type_count_total",
-		Help:      "Counter of DNS requests per type, per zone.",
-	}, []string{"zone", "type"})
-
-	ResponseSize = prometheus.NewHistogramVec(prometheus.HistogramOpts{
-		Namespace: middleware.Namespace,
-		Subsystem: subsystem,
-		Name:      "response_size_bytes",
-		Help:      "Size of the returned response in bytes.",
-		Buckets:   []float64{0, 100, 200, 300, 400, 511, 1023, 2047, 4095, 8291, 16e3, 32e3, 48e3, 64e3},
-	}, []string{"zone", "proto"})
-
-	ResponseRcode = prometheus.NewCounterVec(prometheus.CounterOpts{
-		Namespace: middleware.Namespace,
-		Subsystem: subsystem,
-		Name:      "response_rcode_count_total",
-		Help:      "Counter of response status codes.",
-	}, []string{"zone", "rcode"})
-)
-
-const (
-	subsystem = "dns"
-
-	// Dropped indicates we dropped the query before any handling. It has no closing dot, so it can not be a valid zone.
-	Dropped = "dropped"
-)