Added LabelRename functionality to enable label normalization (for ECS for now)

Makefile

@@ -56,6 +56,9 @@ validate-only:
 
 validate: validate-deps validate-only
 
+run-docker-dev:
+	docker run --rm -it -v $(WORKDIR):/go/src/github.com/newrelic/nri-docker golang:1.10
+
 compile-deps:
 	@echo "=== $(INTEGRATION) === [ compile-deps ]: installing build dependencies..."
 	@$(GO) get -v -d -t ./...

src/nri/sampler.go

@@ -89,7 +89,13 @@ func (cs *ContainerSampler) SampleAll(i *integration.Integration) error {
 			return err
 		}
 
-		shortContainerID := container.ID[:shortContainerIDLength]
+		var shortContainerID string
+		if len(container.ID) > shortContainerIDLength {
+			shortContainerID = container.ID[:shortContainerIDLength]
+		} else {
+			shortContainerID = container.ID
+		}
+
 		ms := entity.NewMetricSet(containerSampleName,
 			metric.Attr(attrContainerID, container.ID),
 			metric.Attr(attrShortContainerID, shortContainerID),
@@ -145,9 +151,29 @@ func attributes(container types.Container) []entry {
 	}
 }
 
+// labelRename contains a list of labels that should be
+// renamed. It does not rename the label in place, but creates
+// a copy to ensure we are not deleting any data.
+var labelRename = map[string]string{
+	"com.amazonaws.ecs.container-name":          "ecsContainerName",
+	"com.amazonaws.ecs.cluster":                 "ecsClusterName",
+	"com.amazonaws.ecs.task-arn":                "ecsTaskArn",
+	"com.amazonaws.ecs.task-definition-family":  "ecsTaskDefinitionFamily",
+	"com.amazonaws.ecs.task-definition-version": "ecsTaskDefinitionVersion",
+}
+
 func labels(container types.Container) []entry {
 	metrics := make([]entry, 0, len(container.Labels))
 	for key, val := range container.Labels {
+
+		if newName, ok := labelRename[key]; ok {
+			metrics = append(metrics, entry{
+				Name:  newName,
+				Value: val,
+				Type:  metric.ATTRIBUTE,
+			})
+		}
+
 		metrics = append(metrics, entry{
 			Name:  labelPrefix + key,
 			Value: val,

src/nri/sampler_test.go

@@ -0,0 +1,112 @@
+package nri
+
+import (
+	"context"
+	"testing"
+
+	"github.com/newrelic/infra-integrations-sdk/integration"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/docker/docker/api/types"
+
+	"github.com/stretchr/testify/mock"
+
+	"github.com/newrelic/nri-docker/src/biz"
+)
+
+// mocker is a Docker mock
+type mocker struct {
+	mock.Mock
+}
+
+func (m *mocker) ContainerList(ctx context.Context, options types.ContainerListOptions) ([]types.Container, error) {
+	args := m.Called(ctx, options)
+	return args.Get(0).([]types.Container), args.Error(1)
+}
+
+func (m *mocker) ContainerInspect(ctx context.Context, containerID string) (types.ContainerJSON, error) {
+	args := m.Called(ctx, containerID)
+	return args.Get(0).(types.ContainerJSON), args.Error(1)
+}
+
+type mockStorer struct {
+	mock.Mock
+}
+
+func (m *mockStorer) Set(key string, value interface{}) int64 {
+	args := m.Called(key, value)
+	return args.Get(0).(int64)
+}
+func (m *mockStorer) Get(key string, valuePtr interface{}) (int64, error) {
+	args := m.Called(key, valuePtr)
+	return args.Get(0).(int64), args.Error(1)
+}
+func (m *mockStorer) Delete(key string) error {
+	return m.Called(key).Error(0)
+}
+func (m *mockStorer) Save() error {
+	return m.Called().Error(0)
+}
+
+func TestECSLabelRename(t *testing.T) {
+	var (
+		givenLabels = map[string]string{
+			"com.amazonaws.ecs.container-name":          "the-container-name",
+			"com.amazonaws.ecs.cluster":                 "the-cluster-name",
+			"com.amazonaws.ecs.task-arn":                "the-task-arn",
+			"com.amazonaws.ecs.task-definition-family":  "the-task-definition-family",
+			"com.amazonaws.ecs.task-definition-version": "the-task-definition-version",
+			"my-label-name":                             "my-label-value",
+		}
+		expectedLabels = map[string]string{
+			// the original labels
+			"label.com.amazonaws.ecs.container-name":          "the-container-name",
+			"label.com.amazonaws.ecs.cluster":                 "the-cluster-name",
+			"label.com.amazonaws.ecs.task-arn":                "the-task-arn",
+			"label.com.amazonaws.ecs.task-definition-family":  "the-task-definition-family",
+			"label.com.amazonaws.ecs.task-definition-version": "the-task-definition-version",
+			// the normalized ECS labels, not prefixed with "label."
+			"ecsContainerName":         "the-container-name",
+			"ecsClusterName":           "the-cluster-name",
+			"ecsTaskArn":               "the-task-arn",
+			"ecsTaskDefinitionFamily":  "the-task-definition-family",
+			"ecsTaskDefinitionVersion": "the-task-definition-version",
+			// the random label
+			"label.my-label-name": "my-label-value",
+		}
+	)
+	mocker := &mocker{}
+	mocker.On("ContainerList", mock.Anything, mock.Anything).Return([]types.Container{
+		{
+			ID:      "containerid",
+			Names:   []string{"Container 1"},
+			Image:   "my_image",
+			ImageID: "my_image_id",
+			Labels:  givenLabels,
+		},
+	}, nil)
+
+	mStore := &mockStorer{}
+	mStore.On("Save").Return(nil)
+
+	sampler := ContainerSampler{
+		metrics: biz.NewProcessor(mStore, nil, mocker),
+		docker:  mocker,
+		store:   mStore,
+	}
+
+	i, err := integration.New("test", "test-version")
+	assert.NoError(t, err)
+	assert.NoError(t, sampler.SampleAll(i))
+
+	for expectedName, expectedValue := range expectedLabels {
+		value, ok := i.Entities[0].Metrics[0].Metrics[expectedName]
+		if !ok {
+			t.Errorf("Expected label '%s=%s' not found.", expectedName, expectedValue)
+		}
+
+		if value != expectedValue {
+			t.Errorf("Label %s has value of %v, expected %s", expectedName, value, expectedValue)
+		}
+	}
+}