Getting all VirtualMachines using API (rbvmomi)

I would like to see some info for all the virtualmachines in my vcenter, right now I have:

require 'rbvmomi'

vim1 = RbVmomi::VIM.connect host: 'vcenter.foo.tld', ssl: true, insecure: true, user: 'keith', password: 'NSABACKDOOR' 
dc1 = vim1.serviceInstance.find_datacenter("Datacenter Name") or fail "datacenter not found"

def list_vms(dc,vim)
  dc.vmFolder.children.each do |vm| 
    if vm.is_a? RbVmomi::VIM::VirtualMachine
      puts vm.name
    end
  end
end

list_vms(dc1,vim1)

But that only returns the hosts (i.e. puts hostnames) in one datacenter, and only those that are in the top level in the folder-hierarchy. I need them all, no matter where.

Almost there - I had exactly the same issue - your loop is skipping subfolders. To get all of the VMs, you need to recurse down thru them. Try something like this (ripped from my own working code):

def vms(folder) # recursively go thru a folder, dumping vm info
   folder.childEntity.each do |x|
      name, junk = x.to_s.split('(')
      case name
      when "Folder"
         vms(x)
      when "VirtualMachine"
         puts x.name
      else
         puts "# Unrecognized Entity " + x.to_s
      end
   end
end

That's obviously starting at the top-level folder in a datacenter, not the DC itself. I don't actually have multiple datacenters in my setup - but it doesn't appear that find_datacenter supports something like .each - so you'd probably want to wrap that up in a loop like:

 dcs = ['firstdc', 'seconddc', 'thirddc']
 dcs.each do |dc|
    vms(vim1.serviceInstance.find_datacenter(dc).vmFolder)
 end