Merge pull request google#2600 from dqminh/raw-container-process-stat

Allow raw container to retrieve process stats
qijun · Jun 25, 2020 · 6f30891 · 6f30891
2 parents 8851fa6 + 8fdcc6d
commit 6f30891
Showing 1 changed file with 48 additions and 44 deletions.
diff --git a/container/libcontainer/handler.go b/container/libcontainer/handler.go
@@ -118,56 +118,58 @@ func (h *Handler) GetStats() (*info.ContainerStats, error) {
 	}
 
 	// If we know the pid then get network stats from /proc/<pid>/net/dev
-	if h.pid == 0 {
-		return stats, nil
-	}
-	if h.includedMetrics.Has(container.NetworkUsageMetrics) {
-		netStats, err := networkStatsFromProc(h.rootFs, h.pid)
-		if err != nil {
-			klog.V(4).Infof("Unable to get network stats from pid %d: %v", h.pid, err)
-		} else {
-			stats.Network.Interfaces = append(stats.Network.Interfaces, netStats...)
-		}
-	}
-	if h.includedMetrics.Has(container.NetworkTcpUsageMetrics) {
-		t, err := tcpStatsFromProc(h.rootFs, h.pid, "net/tcp")
-		if err != nil {
-			klog.V(4).Infof("Unable to get tcp stats from pid %d: %v", h.pid, err)
-		} else {
-			stats.Network.Tcp = t
+	if h.pid > 0 {
+		if h.includedMetrics.Has(container.NetworkUsageMetrics) {
+			netStats, err := networkStatsFromProc(h.rootFs, h.pid)
+			if err != nil {
+				klog.V(4).Infof("Unable to get network stats from pid %d: %v", h.pid, err)
+			} else {
+				stats.Network.Interfaces = append(stats.Network.Interfaces, netStats...)
+			}
 		}
+		if h.includedMetrics.Has(container.NetworkTcpUsageMetrics) {
+			t, err := tcpStatsFromProc(h.rootFs, h.pid, "net/tcp")
+			if err != nil {
+				klog.V(4).Infof("Unable to get tcp stats from pid %d: %v", h.pid, err)
+			} else {
+				stats.Network.Tcp = t
+			}
 
-		t6, err := tcpStatsFromProc(h.rootFs, h.pid, "net/tcp6")
-		if err != nil {
-			klog.V(4).Infof("Unable to get tcp6 stats from pid %d: %v", h.pid, err)
-		} else {
-			stats.Network.Tcp6 = t6
-		}
+			t6, err := tcpStatsFromProc(h.rootFs, h.pid, "net/tcp6")
+			if err != nil {
+				klog.V(4).Infof("Unable to get tcp6 stats from pid %d: %v", h.pid, err)
+			} else {
+				stats.Network.Tcp6 = t6
+			}
 
-	}
-	if h.includedMetrics.Has(container.NetworkAdvancedTcpUsageMetrics) {
-		ta, err := advancedTCPStatsFromProc(h.rootFs, h.pid, "net/netstat", "net/snmp")
-		if err != nil {
-			klog.V(4).Infof("Unable to get advanced tcp stats from pid %d: %v", h.pid, err)
-		} else {
-			stats.Network.TcpAdvanced = ta
 		}
-	}
-	if h.includedMetrics.Has(container.NetworkUdpUsageMetrics) {
-		u, err := udpStatsFromProc(h.rootFs, h.pid, "net/udp")
-		if err != nil {
-			klog.V(4).Infof("Unable to get udp stats from pid %d: %v", h.pid, err)
-		} else {
-			stats.Network.Udp = u
+		if h.includedMetrics.Has(container.NetworkAdvancedTcpUsageMetrics) {
+			ta, err := advancedTCPStatsFromProc(h.rootFs, h.pid, "net/netstat", "net/snmp")
+			if err != nil {
+				klog.V(4).Infof("Unable to get advanced tcp stats from pid %d: %v", h.pid, err)
+			} else {
+				stats.Network.TcpAdvanced = ta
+			}
 		}
+		if h.includedMetrics.Has(container.NetworkUdpUsageMetrics) {
+			u, err := udpStatsFromProc(h.rootFs, h.pid, "net/udp")
+			if err != nil {
+				klog.V(4).Infof("Unable to get udp stats from pid %d: %v", h.pid, err)
+			} else {
+				stats.Network.Udp = u
+			}
 
-		u6, err := udpStatsFromProc(h.rootFs, h.pid, "net/udp6")
-		if err != nil {
-			klog.V(4).Infof("Unable to get udp6 stats from pid %d: %v", h.pid, err)
-		} else {
-			stats.Network.Udp6 = u6
+			u6, err := udpStatsFromProc(h.rootFs, h.pid, "net/udp6")
+			if err != nil {
+				klog.V(4).Infof("Unable to get udp6 stats from pid %d: %v", h.pid, err)
+			} else {
+				stats.Network.Udp6 = u6
+			}
 		}
 	}
+	// some process metrics are per container ( number of processes, number of
+	// file descriptors etc.) and not required a proper container's
+	// root PID (systemd services don't have the root PID atm)
 	if h.includedMetrics.Has(container.ProcessMetrics) {
 		paths := h.cgroupManager.GetPaths()
 		path, ok := paths["cpu"]
@@ -298,13 +300,15 @@ func processStatsFromProcs(rootFs string, cgroupPath string, rootPid int) (info.
 			}
 		}
 	}
-	ulimits := processRootProcUlimits(rootFs, rootPid)
 
 	processStats := info.ProcessStats{
 		ProcessCount: uint64(len(pids)),
 		FdCount:      fdCount,
 		SocketCount:  socketCount,
-		Ulimits:      ulimits,
+	}
+
+	if rootPid > 0 {
+		processStats.Ulimits = processRootProcUlimits(rootFs, rootPid)
 	}
 
 	return processStats, nil