Follow golang/wiki recommendation for tool dependencies and reduce install tools set (#578)

* Reduce `install-tools`

Keeping only go get golang.org/x/lint/golint

* Follow golang/wiki recommendation for tool dependencies

This ensures that everyone is using the same version of golint, we will have to manually
update it when appropriate.

* Exclude tools/ from sources to avoid error msg

Author: Paulo Janotti

Makefile

@@ -1,6 +1,7 @@
 # More exclusions can be added similar with: -not -path './vendor/*'
 ALL_SRC := $(shell find . -name '*.go' \
                                 -not -path './vendor/*' \
+                                -not -path './tools/*' \
                                 -type f | sort)
 
 # ALL_PKGS is used with 'go cover'
@@ -78,11 +79,7 @@ vet:
 
 .PHONY: install-tools
 install-tools:
-	go get -u golang.org/x/lint/golint
-	go get -u github.com/google/go-cmp/cmp
-	go get contrib.go.opencensus.io/exporter/jaeger@v0.1.1-0.20190430175949-e8b55949d948
-	go get contrib.go.opencensus.io/exporter/prometheus
-	go get contrib.go.opencensus.io/exporter/zipkin
+	go install golang.org/x/lint/golint
 
 .PHONY: agent
 agent:

go.mod

@@ -57,11 +57,7 @@ require (
 	go.uber.org/atomic v1.3.2 // indirect
 	go.uber.org/multierr v1.1.0 // indirect
 	go.uber.org/zap v1.9.1
-	golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8 // indirect
-	golang.org/x/lint v0.0.0-20190409202823-959b441ac422 // indirect
-	golang.org/x/net v0.0.0-20190611141213-3f473d35a33a // indirect
-	golang.org/x/sys v0.0.0-20190610200419-93c9922d18ae // indirect
-	golang.org/x/tools v0.0.0-20190612180059-59534d075a87 // indirect
+	golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3
 	google.golang.org/api v0.5.0
 	google.golang.org/grpc v1.21.0
 	gopkg.in/DataDog/dd-trace-go.v1 v1.12.1 // indirect

go.sum

@@ -420,6 +420,7 @@ golang.org/x/exp v0.0.0-20190125153040-c74c464bbbf2/go.mod h1:CJ0aWSM057203Lf6IL
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
 golang.org/x/lint v0.0.0-20190301231843-5614ed5bae6f/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
+golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3 h1:XQyxROzUlZH+WIQwySDgnISgOivlhjIEwaQaJEJrrN0=
 golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/lint v0.0.0-20190409202823-959b441ac422 h1:QzoH/1pFpZguR8NrRHLcO6jKqfv2zpuSqZLgdm7ZmjI=
 golang.org/x/lint v0.0.0-20190409202823-959b441ac422/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
@@ -487,6 +488,7 @@ golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGm
 golang.org/x/tools v0.0.0-20190206041539-40960b6deb8e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+golang.org/x/tools v0.0.0-20190312170243-e65039ee4138 h1:H3uGjxCR/6Ds0Mjgyp7LMK81+LvmbvWWEnJhzk1Pi9E=
 golang.org/x/tools v0.0.0-20190312170243-e65039ee4138/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/tools v0.0.0-20190612180059-59534d075a87 h1:RZgRBvCwrKVLcEd+O/QbyISA6RAPPLTYHdPw4Nk0Wz0=
 golang.org/x/tools v0.0.0-20190612180059-59534d075a87/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=

tools/tools.go

@@ -0,0 +1,25 @@
+// Copyright 2019, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// +build tools
+
+// Package tools follows the recommendation at
+// https://github.com/golang/go/wiki/Modules#how-can-i-track-tool-dependencies-for-a-module
+// on how to add tooling dependencies.
+package tools
+
+import (
+	_ "golang.org/x/lint/golint"
+)