[Metricbeat] Further revise check for bad data in docker/memory (#17400)

* use OR to check for missing data and report lack of memory data

* add changelog entry

* remove space

CHANGELOG.next.asciidoc

@@ -137,6 +137,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Use max in k8s overview dashboard aggregations. {pull}17015[17015]
 - Fix Disk Used and Disk Usage visualizations in the Metricbeat System dashboards. {issue}12435[12435] {pull}17272[17272]
 - Fix missing Accept header for Prometheus and OpenMetrics module. {issue}16870[16870] {pull}17291[17291]
+- Further revise check for bad data in docker/memory. {pull}17400[17400] 
 - Fix issue in Jolokia module when mbean contains multiple quoted properties. {issue}17375[17375] {pull}17374[17374]
 - Combine cloudwatch aggregated metrics into single event. {pull}17345[17345]
 

metricbeat/module/docker/memory/helper.go

@@ -51,7 +51,7 @@ func (s *MemoryService) getMemoryStatsList(containers []docker.Stat, dedot bool)
  //during this time, there doesn't appear to be any meaningful data,
  // and Limit will never be 0 unless the container is not running
  //and there's no cgroup data, and CPU usage should be greater than 0 for any running container.
- if containerStats.Stats.MemoryStats.Limit == 0 && containerStats.Stats.PreCPUStats.CPUUsage.TotalUsage == 0 {
+ if containerStats.Stats.MemoryStats.Limit == 0 || containerStats.Stats.PreCPUStats.CPUUsage.TotalUsage == 0 {
  continue
  }
  formattedStats = append(formattedStats, s.getMemoryStats(containerStats, dedot))

metricbeat/module/docker/memory/memory.go

@@ -20,6 +20,8 @@
 package memory
 
 import (
+ "fmt"
+
  "github.com/docker/docker/client"
  "github.com/pkg/errors"
 
@@ -70,6 +72,9 @@ func (m *MetricSet) Fetch(r mb.ReporterV2) error {
  }
 
  memoryStats := m.memoryService.getMemoryStatsList(stats, m.dedot)
+ if len(memoryStats) == 0 {
+ return fmt.Errorf("No memory stats data available")
+ }
  eventsMapping(r, memoryStats)
 
  return nil

metricbeat/module/docker/memory/memory_test.go

@@ -109,6 +109,22 @@ func TestMemoryService_GetMemoryStats(t *testing.T) {
  assert.Equal(t, expectedFields, event.MetricSetFields)
 }
 
+func TestMemoryServiceBadData(t *testing.T) {
+
+ badMemStats := types.StatsJSON{
+ Stats: types.Stats{
+ Read: time.Now(),
+ MemoryStats: types.MemoryStats{}, //Test for cases where this is empty
+ },
+ }
+
+ memoryService := &MemoryService{}
+ memoryRawStats := []docker.Stat{docker.Stat{Stats: badMemStats}}
+ rawStats := memoryService.getMemoryStatsList(memoryRawStats, false)
+ assert.Len(t, rawStats, 0)
+
+}
+
 func getMemoryStats(read time.Time, number uint64) types.StatsJSON {
 
  myMemoryStats := types.StatsJSON{