fix possible erroneous return if sync and fetch occur simultaneously

app/app.go

@@ -76,11 +76,6 @@ func Run() {
 	})
 
 	router.GET("/", func(c *gin.Context) {
-		if !cluster.OK {
-			c.JSON(http.StatusInternalServerError, gin.H{"error": "cluster state is invalid"})
-			return
-		}
-
 		v, err := cluster.Get()
 		if err != nil {
 			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
@@ -92,11 +87,6 @@ func Run() {
 	})
 
 	router.GET("/nodes/:node", func(c *gin.Context) {
-		if !cluster.OK {
-			c.JSON(http.StatusInternalServerError, gin.H{"error": "cluster state is invalid"})
-			return
-		}
-
 		nodeid := c.Param("node")
 		node, err := cluster.GetNode(nodeid)
 		if err != nil {
@@ -109,30 +99,19 @@ func Run() {
 	})
 
 	router.GET("/nodes/:node/instances/:vmid", func(c *gin.Context) {
-		if !cluster.OK {
-			c.JSON(http.StatusInternalServerError, gin.H{"error": "cluster state is invalid"})
-			return
-		}
-
 		nodeid := c.Param("node")
 		vmid, err := strconv.ParseUint(c.Param("vmid"), 10, 64)
 		if err != nil {
 			c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("%s could not be converted to vmid (uint)", c.Param("instance"))})
 			return
 		}
-		node, err := cluster.GetNode(nodeid)
+		instance, err := cluster.GetInstance(nodeid, vmid)
 		if err != nil {
-			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
 			return
 		} else {
-			instance, err := node.GetInstance(uint(vmid))
+			c.JSON(http.StatusOK, gin.H{"instance": instance})
-			if err != nil {
+			return
-				c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
-				return
-			} else {
-				c.JSON(http.StatusOK, gin.H{"instance": instance})
-				return
-			}
 		}
 	})
 
@@ -172,7 +151,7 @@ func Run() {
 		}
 		start := time.Now()
 		log.Printf("[INFO] starting %s.%d sync\n", nodeName, vmid)
-		err = SyncInstance(&cluster, nodeName, uint(vmid))
+		err = SyncInstance(&cluster, nodeName, vmid)
 		if err != nil {
 			log.Printf("[ERR ] failed to sync %s.%d: %s", nodeName, vmid, err.Error())
 			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})

app/model.go

@@ -28,15 +28,15 @@ func (cluster *Cluster) Get() (*Cluster, error) {
 }
 
 func SyncCluster(cluster *Cluster) error {
-	cluster.OK = false
-
 	err := cluster.BuildCluster()
 	if err != nil {
+		cluster.OK = false
 		return err
 	}
 
 	err = cluster.ResolvePoolMembership()
 	if err != nil {
+		cluster.OK = false
 		return err
 	}
 
@@ -135,6 +135,10 @@ func (cluster *Cluster) GetNode(nodeName string) (*Node, error) {
 	cluster.lock.Lock()
 	defer cluster.lock.Unlock()
 
+	if !cluster.OK {
+		return nil, fmt.Errorf("cluster state is invalid")
+	}
+
 	// get node
 	node, ok := cluster.Nodes[nodeName]
 	if !ok {
@@ -149,15 +153,15 @@ func (cluster *Cluster) GetNode(nodeName string) (*Node, error) {
 }
 
 func SyncNode(cluster *Cluster, nodeName string) error {
-	cluster.OK = false
-
 	err := cluster.BuildNode(nodeName)
 	if err != nil {
+		cluster.OK = false
 		return err
 	}
 
 	err = cluster.ResolvePoolMembership()
 	if err != nil {
+		cluster.OK = false
 		return err
 	}
 
@@ -195,7 +199,7 @@ func (cluster *Cluster) BuildNode(nodeName string) error {
 	for _, vmid := range vms {
 		wg.Go(func() error {
 			start := time.Now()
-			err := node.BuildInstance(VM, vmid)
+			err := node.BuildInstance(VM, paas.SafeUint64(vmid))
 			if err != nil { // if an error was encountered, continue and log the error
 				log.Printf("[ERR ] error encountered while syncing vm %s.%d: %s", nodeName, vmid, err)
 			} else {
@@ -213,7 +217,7 @@ func (cluster *Cluster) BuildNode(nodeName string) error {
 	for _, vmid := range cts {
 		wg.Go(func() error {
 			start := time.Now()
-			err := node.BuildInstance(CT, vmid)
+			err := node.BuildInstance(CT, paas.SafeUint64(vmid))
 			if err != nil { // if an error was encountered, continue and log the error
 				log.Printf("[ERR ] error encountered while syncing ct %s.%d: %s", nodeName, vmid, err)
 			} else {
@@ -247,7 +251,21 @@ func (cluster *Cluster) BuildNode(nodeName string) error {
 	return nil
 }
 
-func (node *Node) GetInstance(vmid uint) (*Instance, error) {
+func (cluster *Cluster) GetInstance(nodeName string, vmid uint64) (*Instance, error) {
+	// aquire cluster lock
+	cluster.lock.Lock()
+	defer cluster.lock.Unlock()
+
+	if !cluster.OK {
+		return nil, fmt.Errorf("cluster state is invalid")
+	}
+
+	// get node
+	node, ok := cluster.Nodes[nodeName]
+	if !ok {
+		return nil, fmt.Errorf("%s not in cluster", nodeName)
+	}
+
 	// aquire node lock
 	node.lock.Lock()
 	defer node.lock.Unlock()
@@ -265,26 +283,28 @@ func (node *Node) GetInstance(vmid uint) (*Instance, error) {
 	}
 }
 
-func SyncInstance(cluster *Cluster, nodeName string, vmid uint) error {
+func SyncInstance(cluster *Cluster, nodeName string, vmid uint64) error {
-	cluster.OK = false
-
 	node, err := cluster.GetNode(nodeName)
 	if err != nil {
+		cluster.OK = false
 		return err
 	}
 
-	instance, err := node.GetInstance(uint(vmid))
+	instance, err := cluster.GetInstance(nodeName, vmid)
 	if err != nil {
+		cluster.OK = false
 		return err
 	}
 
-	err = node.BuildInstance(instance.Type, uint(vmid))
+	err = node.BuildInstance(instance.Type, vmid)
 	if err != nil {
+		cluster.OK = false
 		return err
 	}
 
 	err = cluster.ResolvePoolMembership()
 	if err != nil {
+		cluster.OK = false
 		return err
 	}
 
@@ -294,7 +314,7 @@ func SyncInstance(cluster *Cluster, nodeName string, vmid uint) error {
 
 // hard sync instance
 // returns error if the instance could not be reached
-func (node *Node) BuildInstance(instancetype InstanceType, vmid uint) error {
+func (node *Node) BuildInstance(instancetype InstanceType, vmid uint64) error {
 	instanceID := InstanceID(vmid)
 	var instance *Instance
 	var err error

app/proxmox.go

@@ -174,7 +174,7 @@ func (host *Node) VirtualMachines() ([]uint, error) {
 }
 
 // Get a VM's CPU, Memory but does not recursively link Devices, Disks, Drives, Nets
-func (host *Node) VirtualMachine(VMID uint) (*Instance, error) {
+func (host *Node) VirtualMachine(VMID uint64) (*Instance, error) {
 	instance := Instance{}
 	vm, err := host.pvenode.VirtualMachine(context.Background(), int(VMID))
 	if err != nil {
@@ -221,7 +221,7 @@ func (host *Node) Containers() ([]uint, error) {
 }
 
 // Get a CT's CPU, Memory, Swap but does not recursively link Devices, Disks, Drives, Nets
-func (host *Node) Container(VMID uint) (*Instance, error) {
+func (host *Node) Container(VMID uint64) (*Instance, error) {
 	instance := Instance{}
 	ct, err := host.pvenode.Container(context.Background(), int(VMID))
 	if err != nil {