modules: cleanup modules support, fix DataDog/dd-trace-go problem (#2680)

cleanup modules support, fix DataDog/dd-trace-go probem, add go.mod tidyness check.

go.mod

@@ -3,70 +3,69 @@ module github.com/coredns/coredns
 go 1.12
 
 require (
-	cloud.google.com/go v0.28.0
-	github.com/DataDog/dd-trace-go v0.6.1
-	github.com/Shopify/sarama v1.17.0
-	github.com/apache/thrift v0.12.0
+	github.com/Shopify/sarama v1.21.0 // indirect
 	github.com/aws/aws-sdk-go v1.14.17
 	github.com/coredns/proxy v0.0.0-20190312112157-36a505170348
+	github.com/coreos/bbolt v1.3.2 // indirect
 	github.com/coreos/etcd v3.3.11+incompatible
-	github.com/davecgh/go-spew v1.1.0
+	github.com/coreos/go-semver v0.2.0 // indirect
+	github.com/coreos/go-systemd v0.0.0-20190212144455-93d5ec2c7f76 // indirect
+	github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f // indirect
+	github.com/dgrijalva/jwt-go v3.2.0+incompatible // indirect
 	github.com/dnstap/golang-dnstap v0.0.0-20170829151710-2cf77a2b5e11
-	github.com/eapache/go-resiliency v1.1.0
-	github.com/eapache/go-xerial-snappy v0.0.0-20160609142408-bb955e01b934
-	github.com/eapache/queue v1.1.0
-	github.com/evanphx/json-patch v4.1.0+incompatible
 	github.com/farsightsec/golang-framestream v0.0.0-20181102145529-8a0cb8ba8710
-	github.com/go-ini/ini v1.37.0
-	github.com/go-logfmt/logfmt v0.3.0
-	github.com/gogo/protobuf v1.0.0
+	github.com/go-ini/ini v1.42.0 // indirect
+	github.com/go-logfmt/logfmt v0.4.0 // indirect
+	github.com/gogo/protobuf v1.2.1 // indirect
+	github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef // indirect
 	github.com/golang/protobuf v1.2.0
-	github.com/golang/snappy v0.0.0-20180518054509-2e65f85255db
-	github.com/google/btree v0.0.0-20180124185431-e89373fe6b4a
-	github.com/google/gofuzz v0.0.0-20170612174753-24818f796faf
-	github.com/googleapis/gnostic v0.2.0
-	github.com/gophercloud/gophercloud v0.0.0-20180928224355-bfc006765209
-	github.com/gregjones/httpcache v0.0.0-20180305231024-9cad4c3443a7
+	github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c // indirect
+	github.com/gophercloud/gophercloud v0.0.0-20190307220656-fe1ba5ce12dd // indirect
+	github.com/gorilla/websocket v1.4.0 // indirect
+	github.com/gregjones/httpcache v0.0.0-20190212212710-3befbb6ad0cc // indirect
+	github.com/grpc-ecosystem/go-grpc-middleware v1.0.0 // indirect
+	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 // indirect
+	github.com/grpc-ecosystem/grpc-gateway v1.8.3 // indirect
 	github.com/grpc-ecosystem/grpc-opentracing v0.0.0-20180507213350-8e809c8a8645
-	github.com/hashicorp/golang-lru v0.0.0-20180201235237-0fb14efe8c47
-	github.com/imdario/mergo v0.3.5
-	github.com/jmespath/go-jmespath v0.0.0-20160202185014-0b12d6b521d8
-	github.com/json-iterator/go v0.0.0-20180701071628-ab8a2e0c74be
-	github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515
+	github.com/hashicorp/golang-lru v0.5.1 // indirect
+	github.com/imdario/mergo v0.3.7 // indirect
+	github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af // indirect
+	github.com/jonboulle/clockwork v0.1.0 // indirect
+	github.com/json-iterator/go v1.1.5 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1
 	github.com/mholt/caddy v0.11.5
 	github.com/miekg/dns v1.1.6
-	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd
-	github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742
-	github.com/opentracing-contrib/go-observer v0.0.0-20170622124052-a52f23424492
+	github.com/modern-go/reflect2 v1.0.1 // indirect
+	github.com/onsi/ginkgo v1.8.0 // indirect
+	github.com/onsi/gomega v1.4.3 // indirect
 	github.com/opentracing/opentracing-go v1.0.2
 	github.com/openzipkin/zipkin-go-opentracing v0.3.4
-	github.com/petar/GoLLRB v0.0.0-20130427215148-53be0d36a84c
-	github.com/peterbourgon/diskv v2.0.1+incompatible
-	github.com/pierrec/lz4 v2.0.3+incompatible
+	github.com/pkg/errors v0.8.1 // indirect
 	github.com/prometheus/client_golang v0.9.2
 	github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910
 	github.com/prometheus/common v0.0.0-20181126121408-4724e9255275
-	github.com/rcrowley/go-metrics v0.0.0-20180503174638-e2704e165165
-	github.com/spf13/pflag v1.0.1
-	github.com/ugorji/go v0.0.0-20161130061742-9c7f9b7a2bc3
-	golang.org/x/crypto v0.0.0-20190228161510-8dd112bcdc25
-	golang.org/x/net v0.0.0-20181201002055-351d144fa1fc
-	golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be
+	github.com/sirupsen/logrus v1.4.0 // indirect
+	github.com/smartystreets/goconvey v0.0.0-20190306220146-200a235640ff // indirect
+	github.com/soheilhy/cmux v0.1.4 // indirect
+	github.com/spf13/pflag v1.0.3 // indirect
+	github.com/stretchr/testify v1.3.0 // indirect
+	github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5 // indirect
+	github.com/ugorji/go/codec v0.0.0-20190309163734-c4a1c341dc93 // indirect
+	github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2 // indirect
+	go.etcd.io/bbolt v1.3.2 // indirect
+	go.uber.org/atomic v1.3.2 // indirect
+	go.uber.org/multierr v1.1.0 // indirect
+	go.uber.org/zap v1.9.1 // indirect
 	golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a
-	golang.org/x/text v0.3.0
-	golang.org/x/time v0.0.0-20180412165947-fbb02b2291d2
-	google.golang.org/appengine v1.2.0
-	google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8
+	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4 // indirect
 	google.golang.org/grpc v1.19.0
 	gopkg.in/DataDog/dd-trace-go.v0 v0.6.1
-	gopkg.in/DataDog/dd-trace-go.v1 v1.10.0
-	gopkg.in/inf.v0 v0.9.1
-	gopkg.in/yaml.v2 v2.2.1
+	gopkg.in/ini.v1 v1.42.0 // indirect
 	k8s.io/api v0.0.0-20181204000039-89a74a8d264d
 	k8s.io/apimachinery v0.0.0-20181127025237-2b1284ed4c93
 	k8s.io/client-go v10.0.0+incompatible
 	k8s.io/klog v0.0.0-20181108234604-8139d8cb77af
-	k8s.io/kube-openapi v0.0.0-20180928202339-9dfdf9be683f
-	sigs.k8s.io/yaml v1.1.0
+	k8s.io/kube-openapi v0.0.0-20190306001800-15615b16d372 // indirect
 )
+
+replace github.com/DataDog/dd-trace-go v0.6.1 => github.com/datadog/dd-trace-go v0.6.1