Add a net health recovery service to Qemu machines

There is a network stability issue in qemu + virtio, affecting
some users after long periods of usage, which can lead to
suspended queue delivery. Until the issue is resolved, add a
temporary recovery service which restarts networking when host
communication becomes inoperable.

[NO NEW TESTS NEEDED]

Signed-off-by: Jason T. Greene <jason.greene@redhat.com>

pkg/machine/ignition/ignition.go

@@ -62,6 +62,7 @@ type DynamicIgnition struct {
 	WritePath  string
 	Cfg        Config
 	Rootful    bool
+	NetRecover bool
 }
 
 func (ign *DynamicIgnition) Write() error {
@@ -97,7 +98,7 @@ func (ign *DynamicIgnition) GenerateIgnitionConfig() error {
 
 	ignStorage := Storage{
 		Directories: getDirs(ign.Name),
-		Files:       getFiles(ign.Name, ign.UID, ign.Rootful, ign.VMType),
+		Files:       getFiles(ign.Name, ign.UID, ign.Rootful, ign.VMType, ign.NetRecover),
 		Links:       getLinks(ign.Name),
 	}
 
@@ -231,6 +232,21 @@ func (ign *DynamicIgnition) GenerateIgnitionConfig() error {
 		}
 		ignSystemd.Units = append(ignSystemd.Units, qemuUnit)
 	}
+
+	if ign.NetRecover {
+		contents, err := GetNetRecoveryUnitFile().ToString()
+		if err != nil {
+			return err
+		}
+
+		recoveryUnit := Unit{
+			Enabled:  BoolToPtr(true),
+			Name:     "net-health-recovery.service",
+			Contents: &contents,
+		}
+		ignSystemd.Units = append(ignSystemd.Units, recoveryUnit)
+	}
+
 	// Only after all checks are done
 	// it's ready create the ingConfig
 	ign.Cfg = Config{
@@ -303,7 +319,7 @@ func getDirs(usrName string) []Directory {
 	return dirs
 }
 
-func getFiles(usrName string, uid int, rootful bool, vmtype define.VMType) []File {
+func getFiles(usrName string, uid int, rootful bool, vmtype define.VMType, netRecover bool) []File {
 	files := make([]File, 0)
 
 	lingerExample := parser.NewUnitFile()
@@ -574,6 +590,23 @@ Delegate=memory pids cpu io
 		},
 	})
 
+	// Only necessary for qemu on mac
+	if netRecover {
+		files = append(files, File{
+			Node: Node{
+				User:  GetNodeUsr("root"),
+				Group: GetNodeGrp("root"),
+				Path:  "/usr/local/bin/net-health-recovery.sh",
+			},
+			FileEmbedded1: FileEmbedded1{
+				Mode: IntToPtr(0755),
+				Contents: Resource{
+					Source: EncodeDataURLPtr(GetNetRecoveryFile()),
+				},
+			},
+		})
+	}
+
 	return files
 }
 
@@ -743,6 +776,37 @@ func (i *IgnitionBuilder) Build() error {
 	return i.dynamicIgnition.Write()
 }
 
+func GetNetRecoveryFile() string {
+	return `#!/bin/bash
+# Verify network health, and bounce the network device if host connectivity
+# is lost. This is a temporary workaround for a known rare qemu/virtio issue
+# that affects some systems
+
+sleep 120 # allow time for network setup on initial boot
+while true; do
+  sleep 30
+  curl -s -o /dev/null --max-time 30 http://192.168.127.1/health
+  if [ "$?" != "0" ]; then
+    echo "bouncing nic due to loss of connectivity with host"
+    ifconfig enp0s1 down; ifconfig enp0s1 up
+  fi
+done
+`
+}
+
+func GetNetRecoveryUnitFile() *parser.UnitFile {
+	recoveryUnit := parser.NewUnitFile()
+	recoveryUnit.Add("Unit", "Description", "Verifies health of network and recovers if necessary")
+	recoveryUnit.Add("Unit", "After", "sshd.socket sshd.service")
+	recoveryUnit.Add("Service", "ExecStart", "/usr/local/bin/net-health-recovery.sh")
+	recoveryUnit.Add("Service", "StandardOutput", "journal")
+	recoveryUnit.Add("Service", "StandardError", "journal")
+	recoveryUnit.Add("Service", "StandardInput", "null")
+	recoveryUnit.Add("Install", "WantedBy", "default.target")
+
+	return recoveryUnit
+}
+
 func DefaultReadyUnitFile() parser.UnitFile {
 	u := parser.NewUnitFile()
 	u.Add("Unit", "After", "remove-moby.service sshd.socket sshd.service")

pkg/machine/qemu/machine.go

@@ -202,6 +202,7 @@ func (v *MachineVM) Init(opts machine.InitOptions) (bool, error) {
 		WritePath:  v.getIgnitionFile(),
 		UID:        v.UID,
 		Rootful:    v.Rootful,
+		NetRecover: useNetworkRecover(),
 	})
 
 	// If the user provides an ignition file, we need to

pkg/machine/qemu/options_darwin.go

@@ -11,3 +11,7 @@ func getRuntimeDir() (string, error) {
 	}
 	return tmpDir, nil
 }
+
+func useNetworkRecover() bool {
+	return true
+}

pkg/machine/qemu/options_freebsd.go

@@ -11,3 +11,7 @@ func getRuntimeDir() (string, error) {
 	}
 	return tmpDir, nil
 }
+
+func useNetworkRecover() bool {
+	return false
+}

pkg/machine/qemu/options_linux.go

@@ -11,3 +11,7 @@ func getRuntimeDir() (string, error) {
 	}
 	return util.GetRootlessRuntimeDir()
 }
+
+func useNetworkRecover() bool {
+	return false
+}

pkg/machine/qemu/options_windows.go

@@ -11,3 +11,7 @@ func getRuntimeDir() (string, error) {
 	}
 	return tmpDir, nil
 }
+
+func useNetworkRecover() bool {
+	return false
+}