Hector Calderon hhcalder92

Here's a step by step guide to convert a Virtualbox .ova to a Vagrant box.

List your VMs to find the VM id you want to convert:

$ VBoxManage list vms
"testing" {a3f59eed-b9c5-4a5f-9977-187f8eb8c4d4}

You can now package the .ova VM as Vagrant box:

The MIT License (MIT)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE

Create Root CA (Done once)

Last update: Nov 2025.

Create Root Key

Attention: this is the key used to sign the certificate requests, anyone holding this can sign certificates on your behalf. So keep it in a safe place!

openssl ecparam -genkey -name secp384r1 | openssl ec -aes256 -out rootCA.key

NOTE: a more up-to-date version of this can be found on my blog

nix-shell and Shebang Lines

A few days ago, version 1.9 of the Nix package manager was released. From the release notes:

nix-shell can now be used as a #!-interpreter. This allows you to write scripts that dynamically fetch their own dependencies.

	#!/bin/bash
	# Usage: ./get_kubeconfig_custom_cluster_rancher2.sh cluster_name
	# Needs to be run on the server running `rancher/rancher` container

	# Check if jq exists
	command -v jq >/dev/null 2>&1 \|\| { echo "jq is not installed. Exiting." >&2; exit 1; }

	# Check if clustername is given
	if [ -z "$1" ]; then
	echo "Usage: $0 [clustername]"

	apiVersion: v1
	kind: ConfigMap
	metadata:
	name: kube-dns
	namespace: kube-system
	data:
	upstreamNameservers: \|
	["upstream.dns.server1", "upstream.dns.server2"]

	# VPC Flow Log fields
	# version account-id interface-id srcaddr dstaddr srcport dstport protocol packets bytes start end action log-status
	# http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/flow-logs.html#flow-log-records
	VPCFLOWLOG %{NUMBER:version:int} %{NUMBER:account-id} %{NOTSPACE:interface-id} %{NOTSPACE:srcaddr} %{NOTSPACE:dstaddr} %{NOTSPACE:srcport:int} %{NOTSPACE:dstport:int} %{NOTSPACE:protocol:int} %{NOTSPACE:packets:int} %{NOTSPACE:bytes:int} %{NUMBER:start:int} %{NUMBER:end:int} %{NOTSPACE:action} %{NOTSPACE:log-status}

	$ cat > /tmp/handler.sh
	#! /bin/bash
	echo auth_ok:1
	echo uid:42
	echo gid:21
	echo dir:/tmp
	echo end
	^D

	$ chmod +x /tmp/handler.sh

	MIT License

	Copyright (c) 2014 Piotr Kuczynski

	Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWAR