List all vCenter VMs with Go (govmomi)

A few months ago I saw a that VMware’s govmomi was updated and since I’ve recently started to learn the Go programming language I thought it would be a good exercise to do something simple like list all virtual machines in a vCenter server.

I’m going to use VMware’s Photon 1.0 TP2 as a development environment since the full install comes with tools such as git and go.  I built a Photon VM using these instructions and performed a full install.  To keep things simple for this post I enabled ssh for root but you’ll probably want to create a user for yourself.

Installing govmomi

Let’s make a directory where we will install govmomi.

mkdir -p $GOPATH/src/

Change into this directory and clone the govmomi repo:

cd $GOPATH/src/
git clone

I’m not sure if I’m doing something wrong but I needed to install these otherwise I received errors when running the examples:

go get
go get
go get

I found these in a travis-ci job, but I no longer have the link.

Running an example

Change into the directory that has the only example that is currently in the repo:

cd govmomi/examples/datastores

There is a single file in this directory named main.go and it will list all the datastores in your vCenter.  Actually if I remember correctly, it will only process the first datacenter in your vCenter.  The program needs several parameters to run and they can be retrieved from shell environment variables or by passing them into the program.   If you want to use shell environment variables, you’ll need to define them.  Here is what mine look like:

export GOVMOMI_URL=’https://vc5c.vmware.local/sdk
export GOVMOMI_USERNAME=’vmware\api’
export GOVMOMI_PASSWORD=’vmware123′
export GOVMOMI_INSECURE=’true’

Now I can run the program as such:

go run main.go

My output looks like this:

Name:                   Type:  Capacity:  Free:
nfs-ds412-momentus1     NFS    683.1GB    148.0GB 
nfs-ds412-5400          NFS    453.9GB    293.6GB 
nfs-ds412-hybrid0       NFS      1.8TB      1.0TB 
nfs-ds412-hybrid1       NFS      1.8TB   1002.9GB 
iscsi-ds412-momentus1-0 VMFS   749.8GB    132.3GB 
local-esx-5-1           VMFS   144.0GB     61.8GB 
diskstation-nfs         NFS    908.0GB    308.7GB
nfs-async               NFS    908.0GB    308.7GB

Alternatively, I could have passed in the parameters:

go run main.go –url https://vmware\\api:vmware123@vc5c.vmware.local/sdk –insecure true

Listing all VMs

Since I’m just learning Go and don’t know much about govmomi, I’m going to modify the datastore program instead of writing one from scratch.  I copied the main.go file to list-vms.go. Most of the changes are pretty straightforward.  Instead of searching for DataStores you need to search for VirtualMachines, etc.  Here are few of the changes that I made:

Line 148:

// Find datastores in datacenter
dss, err := f.DatastoreList(ctx, "*")


// Find virtual machines in datacenter
vms, err := f.VirtualMachineList(ctx, "*")

Line 162:

// Retrieve summary property for all datastores
var dst []mo.Datastore
err = pc.Retrieve(ctx, refs, []string{"summary"}, &dst)
if err != nil {


// Retrieve name property for all vms
var vmt []mo.VirtualMachine
err = pc.Retrieve(ctx, refs, []string{"name"}, &vmt)
if err != nil {

Line 171:

fmt.Fprintf(tw, "Name:\tType:\tCapacity:\tFree:\n")
for _, ds := range dst {
    fmt.Fprintf(tw, "%s\t", ds.Summary.Name)
    fmt.Fprintf(tw, "%s\t", ds.Summary.Type)
    fmt.Fprintf(tw, "%s\t", units.ByteSize(ds.Summary.Capacity))
    fmt.Fprintf(tw, "%s\t", units.ByteSize(ds.Summary.FreeSpace))
    fmt.Fprintf(tw, "\n")


fmt.Println("Virtual machines found:", len(vmt))
for _, vm := range vmt {
  fmt.Fprintf(tw, "%s\n", vm.Name)

I can retrieve a listing of all VMs as such:

go run list-vms.go

Here is the truncated output from my lab:

Virtual machines found: 84
Linux Minimal Template2

Looks good but they aren’t sorted.  Let’s fix that.

Sorting the VMs

I really just wanted to do this to see how to sort in Go.  I used the example here as a reference.

First we need to add “sort” to the import statement.

Next we need to implement the sort.Interface for ByName:

type ByName []mo.VirtualMachine

func (n ByName) Len() int                { return len(n) }
func (n ByName) Swap(i, j int)        { n[i], n[j] = n[j], n[i] }
func (n ByName) Less(i, j int) bool { return n[i].Name < n[j].Name }

Now before we loop through and print out the VM names we sort them first:


Now when I run the program the truncated results look like this:

Virtual machines found: 84
Linux Minimal Template2

You can view the script on github.

Updating vCenter Orchestrator using an ISO repo

In this post I’m going to show how to update vCenter Orchestrator (vCO) to a specific version.  Often when you need to update a VMware appliance such as vCO you simply update to the latest version, but sometimes this isn’t possible because of compatibility issues, needing to keep environments in sync, etc.  In my case I needed to update from vCO 5.5.2 to 5.5.3, but when I tried to update it said the latest version was 7.0.  This is a pretty simple process, but I had to document it for work so I thought I’d document it here as well.

Download the ISO repo

For some reason vCO 5.5.3 isn’t listed in the drop-down box on VMware’s download site, but I changed the URL to and it allowed me to access the 5.5.3 download page.


Apply the update

  1. Mount the ISO to the VM.
  2. Access the Orchestrator administrative page.  For example: https://vco.vmware.local:5480
  3. Select the Update tab > Settings and select Use CDROM Updates2016-01-05_11-11-16.jpg
  4. Select Save Settings
  5. Select the Update tab > Status > Check Updates and now you will see version of vCO that’s on your ISO repo as opposed to whatever the latest version is.2016-01-05_11-12-34.jpg
  6. Reboot the appliance to apply the update by selecting the System tab > Information > Reboot2016-01-05_11-17-27.jpg