feat: Update docker container handler to include health status in stats

container/docker/handler.go

@@ -64,8 +64,9 @@ type dockerContainerHandler struct {
 	creationTime time.Time
 
 	// Metadata associated with the container.
-	envs   map[string]string
-	labels map[string]string
+	envs         map[string]string
+	labels       map[string]string
+	healthStatus string
 
 	// Image name used for this container.
 	image string
@@ -178,6 +179,7 @@ func newDockerContainerHandler(
 		rootfsStorageDir:   rootfsStorageDir,
 		envs:               make(map[string]string),
 		labels:             ctnr.Config.Labels,
+		healthStatus:       ctnr.State.Health.Status,
 		includedMetrics:    metrics,
 		zfsParent:          zfsParent,
 	}
@@ -303,6 +305,9 @@ func (h *dockerContainerHandler) GetSpec() (info.ContainerSpec, error) {
 // TODO(vmarmol): Get from libcontainer API instead of cgroup manager when we don't have to support older Dockers.
 func (h *dockerContainerHandler) GetStats() (*info.ContainerStats, error) {
 	stats, err := h.libcontainerHandler.GetStats()
+
+	stats.Health.Status = h.healthStatus
+
 	if err != nil {
 		return stats, err
 	}

info/v1/container.go

@@ -930,6 +930,11 @@ type ProcessStats struct {
 	Ulimits []UlimitSpec `json:"ulimits,omitempty"`
 }
 
+type Health struct {
+	// Health status of the container
+	Status string `json:"status"`
+}
+
 type ContainerStats struct {
 	// The time of this stat point.
 	Timestamp time.Time               `json:"timestamp"`
@@ -969,6 +974,8 @@ type ContainerStats struct {
 	CpuSet CPUSetStats `json:"cpuset,omitempty"`
 
 	OOMEvents uint64 `json:"oom_events,omitempty"`
+
+	Health Health `json:"health,omitempty"`
 }
 
 func timeEq(t1, t2 time.Time, tolerance time.Duration) bool {

metrics/prometheus.go

@@ -130,6 +130,24 @@ func NewPrometheusCollector(i infoProvider, f ContainerLabelsFunc, includedMetri
 					}}
 				},
 			},
+			{
+				name:      "container_health_state",
+				help:      "The result of the container's health check",
+				valueType: prometheus.GaugeValue,
+				getValues: func(s *info.ContainerStats) metricValues {
+					return metricValues{{
+						// inline if to check if s.health.status = healthy
+						value: func(s *info.ContainerStats) float64 {
+							if s.Health.Status == "healthy" {
+								return 1
+							} else {
+								return 0
+							}
+						}(s),
+						timestamp: s.Timestamp,
+					}}
+				},
+			},
 		},
 		includedMetrics: includedMetrics,
 		opts:            opts,