From 934d7aecfcb096db98674dc85bde605e83fe5400 Mon Sep 17 00:00:00 2001
From: Henrik Hodne <henrik@hodne.io>
Date: Fri, 26 Aug 2016 21:30:39 +0200
Subject: [PATCH] Fetch the list of known hosts and base VMs on boot (#10)

This lets us see hosts that never power on/power off VMs and base images that
don't get cloned instantly.

Fixes #1
---
 CHANGELOG.md                 |  2 +
 cmd/collectd-vsphere/main.go |  5 +++
 vsphere_event_listener.go    | 79 +++++++++++++++++++++++++++++++++++-
 3 files changed, 85 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1eb0dee..5ddec5d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,8 @@
 IMPROVEMENTS:
 
   * Add log messages
+  * Fetch the list of hosts and base VMs on boot to include them in the metrics
+    immediately (#1)
 
 ## v1.0.0 (August 26, 2016)
 
diff --git a/cmd/collectd-vsphere/main.go b/cmd/collectd-vsphere/main.go
index 8e173e9..82a3360 100644
--- a/cmd/collectd-vsphere/main.go
+++ b/cmd/collectd-vsphere/main.go
@@ -76,6 +76,11 @@ func main() {
 				Usage:   "path to the vSphere cluster to monitor events on",
 				EnvVars: []string{"VSPHERE_CLUSTER"},
 			},
+			&cli.StringFlag{
+				Name:    "vsphere-base-vm-folder",
+				Usage:   "path to the vSphere folder containing base VMs",
+				EnvVars: []string{"VSPHERE_BASE_VM_FOLDER"},
+			},
 			&cli.StringFlag{
 				Name:    "sentry-dsn",
 				Usage:   "DSN for Sentry integration",
diff --git a/vsphere_event_listener.go b/vsphere_event_listener.go
index 8e0cb70..eaf4684 100644
--- a/vsphere_event_listener.go
+++ b/vsphere_event_listener.go
@@ -7,6 +7,8 @@ import (
 	"github.com/vmware/govmomi"
 	"github.com/vmware/govmomi/event"
 	"github.com/vmware/govmomi/find"
+	"github.com/vmware/govmomi/object"
+	"github.com/vmware/govmomi/vim25/mo"
 	"github.com/vmware/govmomi/vim25/types"
 	"golang.org/x/net/context"
 )
@@ -24,6 +26,7 @@ type VSphereConfig struct {
 	URL         *url.URL
 	Insecure    bool
 	ClusterPath string
+	BaseVMPath  string
 }
 
 // NewVSphereEventListener creates a VSphereEventListener with a given
@@ -39,7 +42,18 @@ func NewVSphereEventListener(config VSphereConfig, statsCollector *StatsCollecto
 // Start starts the event listener and begins reporting stats to the
 // StatsCollector.
 func (l *VSphereEventListener) Start() error {
-	l.makeClient()
+	err := l.makeClient()
+	if err != nil {
+		return errors.Wrap(err, "couldn't create vSphere client")
+	}
+	err = l.prefillHosts()
+	if err != nil {
+		return errors.Wrap(err, "couldn't prefill hosts")
+	}
+	err = l.prefillBaseVMs()
+	if err != nil {
+		return errors.Wrap(err, "couldn't prefill base VMs")
+	}
 
 	clusterRef, err := l.clusterReference()
 	if err != nil {
@@ -88,3 +102,66 @@ func (l *VSphereEventListener) clusterReference() (types.ManagedObjectReference,
 
 	return cluster.Reference(), nil
 }
+
+func (l *VSphereEventListener) prefillHosts() error {
+	clusterRef, err := l.clusterReference()
+	if err != nil {
+		return errors.Wrap(err, "failed to get reference to compute cluster")
+	}
+
+	hosts, err := object.NewClusterComputeResource(l.client.Client, clusterRef).Hosts(context.TODO())
+	if err != nil {
+		return errors.Wrap(err, "failed to list hosts in compute cluster")
+	}
+
+	for _, host := range hosts {
+		var mhost mo.HostSystem
+		err := host.Properties(context.TODO(), host.Reference(), []string{"summary"}, &mhost)
+		if err != nil {
+			return errors.Wrap(err, "failed to get summary for host")
+		}
+		name := mhost.Summary.Config.Name
+		if name != "" {
+			l.statsCollector.ensureHostExists(name)
+		}
+	}
+
+	return nil
+}
+
+func (l *VSphereEventListener) prefillBaseVMs() error {
+	if l.config.BaseVMPath == "" {
+		// Skip if no base VM path, for backwards compatibility with v1.0.0
+		return nil
+	}
+
+	finder := find.NewFinder(l.client.Client, true)
+	folder, err := finder.Folder(context.TODO(), l.config.BaseVMPath)
+	if err != nil {
+		return errors.Wrap(err, "failed to find base vm folder")
+	}
+
+	children, err := folder.Children(context.TODO())
+	if err != nil {
+		return errors.Wrap(err, "failed to list children of base vm folder")
+	}
+
+	for _, vmRef := range children {
+		vm, ok := vmRef.(*object.VirtualMachine)
+		if !ok {
+			continue
+		}
+
+		var mvm mo.VirtualMachine
+		err := vm.Properties(context.TODO(), vm.Reference(), []string{"config"}, &mvm)
+		if err != nil {
+			return errors.Wrap(err, "failed to get config for base VM")
+		}
+		name := mvm.Config.Name
+		if name != "" {
+			l.statsCollector.ensureBaseVMExists(name)
+		}
+	}
+
+	return nil
+}