toobulkeh

vim = RbVmomi::VIM.connect host: vcenter.hostname, user: vcenter.username, password: vcenter.password, insecure: true
pm = vim.serviceInstance.content.perfManager

# this is for a single cluster with hosts directly in one cluster. 'first' returns the cluster object.
hosts = vim.serviceInstance.find_datacenter.hostFolder.children.first.host

pm.retrieve_stats([hosts[0]], ['cpu.usagemhz'], {interval: '300', start_time: (Time.now - 6.hours)}).first[1][:metrics]['cpu.usagemhz']
# This above query queries for the 'cpu.usagemhz' counter, which by default matches the (none) rollup counter (NOT THE AVERAGE) in vSphere API. 
#   This is a problem with the RbVmomi gem helper function "retrieve_stats" only. To override this, use the following manual counter selection:

caseywdunn

Docker cheat sheet

Introduction

Docker is a tool for bundling together applications and their dependencies into images that can than be run as containers on many different types of computers.

Docker and other containerization tools are useful to scientists because:

• It greatly simplifies distribution and installation of complex work flows that