Add goimports check and fix import order for all files

Updates open-telemetry#155.

Makefile

@@ -11,6 +11,7 @@ GOTEST_OPT?= -race -timeout 30s
 GOTEST_OPT_WITH_COVERAGE = $(GOTEST_OPT) -coverprofile=coverage.txt -covermode=atomic
 GOTEST=go test
 GOFMT=gofmt
+GOIMPORTS=goimports
 GOLINT=golint
 GOVET=go vet
 GOOS=$(shell go env GOOS)
@@ -32,8 +33,8 @@ all-srcs:
 
 .DEFAULT_GOAL := addlicense-fmt-vet-lint-test
 
-.PHONY: addlicense-fmt-vet-lint-test
-addlicense-fmt-vet-lint-test: addlicense fmt vet lint test
+.PHONY: addlicense-fmt-vet-lint-goimports-test
+addlicense-fmt-vet-lint-goimports-test: addlicense fmt vet lint goimports test
 
 .PHONY: e2e-test
 e2e-test: otelsvc
@@ -44,7 +45,7 @@ test:
 	$(GOTEST) $(GOTEST_OPT) $(ALL_PKGS)
 
 .PHONY: travis-ci
-travis-ci: fmt vet lint test-with-cover otelsvc
+travis-ci: fmt vet lint goimports test-with-cover otelsvc
 	$(MAKE) -C testbed install-tools
 	$(MAKE) -C testbed runtests
 
@@ -90,15 +91,28 @@ lint:
 	    echo "Lint finished successfully"; \
 	fi
 
+.PHONY: goimports
+goimports:
+	@IMPORTSOUT=`$(GOIMPORTS) -l . 2>&1`; \
+	if [ "$$IMPORTSOUT" ]; then \
+		echo "$(GOIMPORTS) FAILED => fix the import order in the following files:\n"; \
+		echo "$$IMPORTSOUT\n"; \
+		exit 1; \
+	else \
+	    echo "Goimports finished successfully"; \
+	fi
+
 .PHONY: vet
 vet:
 	@$(GOVET) ./...
 	@echo "Vet finished successfully"
 
 .PHONY: install-tools
 install-tools:
-	GO111MODULE=on go install github.com/google/addlicense
-	GO111MODULE=on go install golang.org/x/lint/golint
+	GO111MODULE=on go install \
+	  github.com/google/addlicense \
+	  golang.org/x/lint/golint \
+    golang.org/x/tools/cmd/goimports
 
 .PHONY: otelsvc
 otelsvc:

internal/tools.go

@@ -26,4 +26,5 @@ import (
 	_ "github.com/google/addlicense"
 	_ "github.com/jstemmer/go-junit-report"
 	_ "golang.org/x/lint/golint"
+	_ "golang.org/x/tools/cmd/goimports"
 )

receiver/prometheusreceiver/internal/metadata.go

@@ -16,6 +16,7 @@ package internal
 
 import (
 	"errors"
+
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/pkg/labels"
 	"github.com/prometheus/prometheus/scrape"

receiver/prometheusreceiver/internal/metricsbuilder.go

@@ -17,20 +17,21 @@ package internal
 import (
 	"errors"
 	"fmt"
-	"github.com/golang/protobuf/ptypes/wrappers"
-	"go.uber.org/zap"
 	"sort"
 	"strconv"
 	"strings"
 
 	commonpb "github.com/census-instrumentation/opencensus-proto/gen-go/agent/common/v1"
 	metricspb "github.com/census-instrumentation/opencensus-proto/gen-go/metrics/v1"
 	"github.com/golang/protobuf/ptypes/timestamp"
-	"github.com/open-telemetry/opentelemetry-service/consumer/consumerdata"
+	"github.com/golang/protobuf/ptypes/wrappers"
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/pkg/labels"
 	"github.com/prometheus/prometheus/pkg/textparse"
 	"github.com/prometheus/prometheus/scrape"
+	"go.uber.org/zap"
+
+	"github.com/open-telemetry/opentelemetry-service/consumer/consumerdata"
 )
 
 const metricsSuffixCount = "_count"

receiver/prometheusreceiver/internal/metricsbuilder_test.go

@@ -15,17 +15,18 @@
 package internal
 
 import (
-	"github.com/golang/protobuf/ptypes/wrappers"
 	"reflect"
 	"testing"
 
 	commonpb "github.com/census-instrumentation/opencensus-proto/gen-go/agent/common/v1"
 	metricspb "github.com/census-instrumentation/opencensus-proto/gen-go/metrics/v1"
-	"github.com/open-telemetry/opentelemetry-service/exporter/exportertest"
+	"github.com/golang/protobuf/ptypes/wrappers"
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/pkg/labels"
 	"github.com/prometheus/prometheus/pkg/textparse"
 	"github.com/prometheus/prometheus/scrape"
+
+	"github.com/open-telemetry/opentelemetry-service/exporter/exportertest"
 )
 
 func Test_isUsefulLabel(t *testing.T) {

receiver/prometheusreceiver/internal/ocastore.go

@@ -17,14 +17,16 @@ package internal
 import (
 	"context"
 	"errors"
-	"github.com/open-telemetry/opentelemetry-service/consumer"
+	"io"
+	"sync"
+	"sync/atomic"
+
 	"github.com/prometheus/prometheus/pkg/labels"
 	"github.com/prometheus/prometheus/scrape"
 	"github.com/prometheus/prometheus/storage"
 	"go.uber.org/zap"
-	"io"
-	"sync"
-	"sync/atomic"
+
+	"github.com/open-telemetry/opentelemetry-service/consumer"
 )
 
 const (

receiver/prometheusreceiver/internal/ocastore_test.go

@@ -17,9 +17,6 @@ package internal
 import (
 	"context"
 	"fmt"
-	"github.com/go-kit/kit/log"
-	"github.com/open-telemetry/opentelemetry-service/consumer/consumerdata"
-	"github.com/prometheus/prometheus/discovery"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -28,9 +25,13 @@ import (
 	"time"
 
 	metricspb "github.com/census-instrumentation/opencensus-proto/gen-go/metrics/v1"
+	"github.com/go-kit/kit/log"
 	"github.com/prometheus/prometheus/config"
 	sd_config "github.com/prometheus/prometheus/discovery/config"
 	"github.com/prometheus/prometheus/scrape"
+
+	"github.com/open-telemetry/opentelemetry-service/consumer/consumerdata"
+	"github.com/prometheus/prometheus/discovery"
 )
 
 func TestOcaStore(t *testing.T) {

receiver/prometheusreceiver/internal/transaction.go

@@ -17,14 +17,16 @@ package internal
 import (
 	"context"
 	"errors"
+	"strings"
+	"sync/atomic"
+
 	commonpb "github.com/census-instrumentation/opencensus-proto/gen-go/agent/common/v1"
-	"github.com/open-telemetry/opentelemetry-service/consumer"
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/pkg/labels"
 	"github.com/prometheus/prometheus/storage"
 	"go.uber.org/zap"
-	"strings"
-	"sync/atomic"
+
+	"github.com/open-telemetry/opentelemetry-service/consumer"
 )
 
 const (

receiver/prometheusreceiver/internal/transaction_test.go

@@ -16,11 +16,12 @@ package internal
 
 import (
 	"context"
-	"github.com/prometheus/prometheus/pkg/labels"
-	"github.com/prometheus/prometheus/scrape"
 	"reflect"
 	"testing"
 	"time"
+
+	"github.com/prometheus/prometheus/pkg/labels"
+	"github.com/prometheus/prometheus/scrape"
 )
 
 func Test_transaction(t *testing.T) {

service/builder/builder.go

@@ -19,6 +19,7 @@ package builder
 import (
 	"flag"
 	"fmt"
+
 	"github.com/spf13/viper"
 )