fix: containerId coming from system driver are correctly parsed (#34)

* fix: containerId coming from system driver are correctly parsed

Makefile

@@ -6,7 +6,7 @@ BINARY_NAME = nri-kubernetes
 E2E_BINARY_NAME := $(BINARY_NAME)-e2e
 
 GOVENDOR_VERSION = 1.0.8
-GOLANGCILINT_VERSION = 1.29
+GOLANGCILINT_VERSION = 1.31.0
 
 .PHONY: all
 all: build

src/kubelet/metric/cadvisor.go

@@ -3,6 +3,7 @@ package metric
 import (
 	"errors"
 	"fmt"
+	"regexp"
 	"strings"
 
 	"github.com/newrelic/nri-kubernetes/src/client"
@@ -19,6 +20,12 @@ const (
 	StandaloneCAdvisorMetricsPath = "/metrics"
 )
 
+var (
+	dockerNativeWithoutSystemD = regexp.MustCompile("^.*([0-9a-f]+)$")
+	dockerNativeWithSystemD    = regexp.MustCompile("^.*\\w+-([0-9a-f]+)\\.scope$")
+	dockerGeneric              = regexp.MustCompile("^([0-9a-f]+)$")
+)
+
 // getLabel returns the first label it finds by the given names
 func getLabel(labels prometheus.Labels, names ...string) (string, bool) {
 	for _, name := range names {
@@ -129,6 +136,21 @@ func createRawEntityID(m prometheus.Metric) (string, error) {
 }
 
 // /kubepods/besteffort/podba8b34d7-11a3-11e8-a084-080027352a02/a949bd136c1397b9f52905538ee11450427be33648abe38db06be2e5cfbeca49
+// /docker/ae17ce6dcd2f27905cedf80609044290eccd98115b4e1ded08fcf6852cf939ae/kubepods.slice/kubepods-besteffort.slice/kubepods-besteffort-pod13118b761000f8fe2c4662d5f32d9532.slice/crio-ebccdd64bb3ef5dfa9d9b167cb5e30f9b696c2694fb7e0783af5575c28be3d1b.scope
+// /docker/d44b560aba016229fd4f87a33bf81e8eaf6c81932a0623530456e8f80f9675ad/kubepods/besteffort/pod6edbcc6c66e4b5af53005f91bf0bc1fd/7588a02459ef3166ba043c5a605c9ce65e4dd250d7ee40428a28d806c4116e97
 func extractContainerID(v string) string {
-	return v[strings.LastIndex(v, "/")+1:]
+	containerID := v[strings.LastIndex(v, "/")+1:]
+	matches := dockerNativeWithSystemD.FindStringSubmatch(containerID)
+	if len(matches) > 0 {
+		return matches[1]
+	}
+	matches = dockerNativeWithoutSystemD.FindStringSubmatch(containerID)
+	if len(matches) > 0 {
+		return matches[0]
+	}
+	matches = dockerGeneric.FindStringSubmatch(containerID)
+	if len(matches) > 0 {
+		return matches[0]
+	}
+	return containerID
 }

src/kubelet/metric/cadvisor_test.go

@@ -88,3 +88,36 @@ container_memory_usage_bytes{container_name="influxdb",id="/kubepods/besteffort/
 
 	assert.ElementsMatch(t, expectedErrs, err.(data.ErrorGroup).Errors)
 }
+
+func TestExtractContainerIdWithoutSystemD_ReturnsCorrectId(t *testing.T) {
+	// given
+	fullContainerID := "/docker/d44b560aba016229fd4f87a33bf81e8eaf6c81932a0623530456e8f80f9675ad/kubepods/besteffort/pod6edbcc6c66e4b5af53005f91bf0bc1fd/7588a02459ef3166ba043c5a605c9ce65e4dd250d7ee40428a28d806c4116e97"
+	expected := "7588a02459ef3166ba043c5a605c9ce65e4dd250d7ee40428a28d806c4116e97"
+
+	// when
+	actual := extractContainerID(fullContainerID)
+
+	assert.Equal(t, expected, actual)
+}
+
+func TestExtractContainerIdWithSystemD_ReturnsCorrectId(t *testing.T) {
+	// given
+	fullContainerID := "/docker/ae17ce6dcd2f27905cedf80609044290eccd98115b4e1ded08fcf6852cf939ae/kubepods.slice/kubepods-besteffort.slice/kubepods-besteffort-pod13118b761000f8fe2c4662d5f32d9532.slice/crio-ebccdd64bb3ef5dfa9d9b167cb5e30f9b696c2694fb7e0783af5575c28be3d1b.scope"
+	expected := "ebccdd64bb3ef5dfa9d9b167cb5e30f9b696c2694fb7e0783af5575c28be3d1b"
+
+	// when
+	actual := extractContainerID(fullContainerID)
+
+	assert.Equal(t, expected, actual)
+}
+
+func TestExtractContainerIdDockerGeneric_ReturnsCorrectId(t *testing.T) {
+	// given
+	fullContainerID := "docker://5a4eefc5b30f6f12402665bd920ee8e889ba9e14bdcc623e2865a79d40f58412"
+	expected := "5a4eefc5b30f6f12402665bd920ee8e889ba9e14bdcc623e2865a79d40f58412"
+
+	// when
+	actual := extractContainerID(fullContainerID)
+
+	assert.Equal(t, expected, actual)
+}