Polar Lights polarlights

Overview

Spring Boot applications can run within a container by Multi-Layer based approach. Each layer may contain different parts of the application such as dependencies, source code, resources and even snapshot dependencies.

In the other hand, with Multi-Stage Build approach, any application can be built at a separate image from the final image that will contain the runnable application.

Spring Boot Docker

Multi-Layer

Change default DNS nameserver used by Kubernetes pods

This can be applied generically but usually applies to Linux nodes that have a local caching nameserver running, which means pointing to an IP in the loopback range (127.0.0.0/8). Ubuntu 18.04 Bionic Beaver does this by default.

Option 1: Change host configuration

sudo systemctl mask systemd-resolved
rm -f /etc/resolv.conf
sudo ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf

Reset mysql root password in Mac OS:

First Stop MySQL:

Go to: 'System Preferences' >> 'MySQL' and stop MySQL

OR,

sudo /usr/local/mysql/support-files/mysql.server start
sudo /usr/local/mysql/support-files/mysql.server stop

Indexes

HTML

Sinatra

Installation:

Dependencies: ruby

gem install sinatra

	require 'cgi'
	require 'json'
	require 'active_support'

	def verify_and_decrypt_session_cookie(cookie, secret_key_base)
	cookie = CGI::unescape(cookie)
	salt = 'encrypted cookie'
	signed_salt = 'signed encrypted cookie'
	key_generator = ActiveSupport::KeyGenerator.new(secret_key_base, iterations: 1000)
	secret = key_generator.generate_key(salt)

	# decode_session_cookie.rb
	# ------------------------
	# The purpose of this script is to show that if I have the secret_key_base
	# and a cookie to an active Rails session, I can decrypt it and gain access
	# to key information about the user's session.

	require 'rubygems'
	require 'cgi'
	require 'active_support'
	require 'action_controller'

	ubuntu@ip-172-31-17-29:~/ansible_docker$ packer build templates/production/docker_mysql.json
	docker output will be in this color.

	==> docker: Creating a temporary directory for sharing data...
	==> docker: Starting docker container...
	docker: Run command: docker run -v /tmp/packer-docker353976599:/packer-files -d -i -t alo7/ubuntu:base_server /bin/bash
	docker: Container ID: 0679b2f24b7cce27257597f18ba8cc5e1616cda9006aa93373a36ab397de1079
	==> docker: Provisioning with shell script: provision/scripts/install_common.sh
	docker: Install common software ...
	docker: Reading package lists...

	require 'bundler/capistrano'

	set :application, "net"
	set :repository, "[email protected]:net.git"

	set :scm, :git

	set :default_environment, {
	'PATH' => "$HOME/.rbenv/shims:$HOME/.rbenv/bin:$PATH"
	}

	# Feel free to change this path of course (and keys_zone value as well, but also change the usage of it below).
	proxy_cache_path /var/www/cache/resized levels=1:2 keys_zone=resizedimages:10m max_size=1G;

	# Gzip was on in another conf file of mine...You may need to uncomment the next line.
	#gzip on;
	gzip_disable msie6;
	gzip_static on;
	gzip_comp_level 4;
	gzip_proxied any;
	# Again, be careful that you aren't overwriting some other setting from another config's http {} section.