Dmytro vorotech

Packer and Ansible with VirtualBox

NOTE: This gist is accompanied by my git repository example-of-packer-and-ansible-with-virtualbox. It contains an example of using Packer and Ansible to create a CentOS 7 VirtualBox machine image.

There did not seem to be much information out there on the internet for this so it seemed worthwhile to pass on this knowledge.

Packer from Hashicorp is a tool for creating machine images. It can be used with plugins, called Provisioners, to extend it.

I use the Ansible Provisioner to execute an Ansible playbook to configure the internals of the virtual machine.

Prow and Quickstart

Prow is a Kubernetes based CI/CD system. Jobs can be triggered by various types of events and report their status to many different services. In addition to job execution, Prow provides GitHub automation in the form of policy enforcement, chat-ops via /foo style commands, and automatic PR merging.

NOTE|WARNING: In order to make Prow work fine with your repo, the Kubernetes cluster MUST be reachable by GitHub Webhook.

Articles to read and understand

Readme file: https://github.com/kubernetes/test-infra/blob/master/prow/README.md
Command Help: https://prow.k8s.io/command-help

Use the Hubble app to get the camera connected to a wifi network.

Find the Camera's IP address:

> sudo arp-scan --interface=enp3s0 --localnet
Interface: enp3s0, datalink type: EN10MB (Ethernet)
Starting arp-scan 1.8.1 with 256 hosts (http://www.nta-monitor.com/tools/arp-scan/)
192.168.1.100	00:19:99:0f:6a:98	Fujitsu Technology Solutions
192.168.1.102	c4:6e:1f:53:f0:8b	(Unknown)

Revert the full commit

Sometimes you may want to undo a whole commit with all changes. Instead of going through all the changes manually, you can simply tell git to revert a commit, which does not even have to be the last one. Reverting a commit means to create a new commit that undoes all changes that were made in the bad commit. Just like above, the bad commit remains there, but it no longer affects the the current master and any future commits on top of it.

git revert {commit_id}

About History Rewriting

Delete the last commit

Deleting the last commit is the easiest case. Let's say we have a remote origin with branch master that currently points to commit dd61ab32. We want to remove the top commit. Translated to git terminology, we want to force the master branch of the origin remote repository to the parent of dd61ab32:

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

Provider	Singleton	Instantiable	Configurable
Constant	Yes	No	No
Value	Yes	No	No
Service	Yes	No	No
Factory	Yes	Yes	No
Decorator	Yes	No?	No
Provider	Yes	Yes	Yes

	// Auth0 custom rule
	// Add Github Organizations to the user metadata
	//
	// This rule need the following configurations values
	// AUTH0_DOMAIN_NAME: your auth0 domain name
	// MANAGEMENT_CLIENT_ID: your auth0 management api client id
	// MANAGEMENT_CLIENT_SECRET: your auth0 management api client secret
	//
	// You have to create an Management API Application with proper
	// scope to allow rule to fetch user organizations.

	FROM nginx:alpine AS builder

	# nginx:alpine contains NGINX_VERSION environment variable, like so:
	# ENV NGINX_VERSION 1.15.0

	# Our NCHAN version
	ENV NCHAN_VERSION 1.1.15

	# Download sources
	RUN wget "http://nginx.org/download/nginx-${NGINX_VERSION}.tar.gz" -O nginx.tar.gz && \

	SELECT table,
	formatReadableSize(sum(bytes)) as size,
	min(min_date) as min_date,
	max(max_date) as max_date
	FROM system.parts
	WHERE active
	GROUP BY table

	#!/bin/bash

	# Copyright © 2017 Google Inc.
	# Licensed under the Apache License, Version 2.0 (the "License");
	# you may not use this file except in compliance with the License.
	# You may obtain a copy of the License at
	#
	# http://www.apache.org/licenses/LICENSE-2.0
	#
	# Unless required by applicable law or agreed to in writing, software