chainhead

Introduction

This file documents the steps I followed to create and deploy an application to an OpenShift cluster. These instructions have been gathered after much trials and tribulations on maxcOS Mojave - YMMV.

Installation - minishift

Since this is an educational exercise, I used minishift - an OpenShift cluster that is just enough to get started. To work with minishift, a CLI tool oc is also installed.

Pre-requisites

chainhead

Introduction

cert-manager is a native Kubernetes certificate management controller. It can help with issuing certificates from a variety of sources, such as Let’s Encrypt, HashiCorp Vault, Venafi, a simple signing key pair, or self signed. For more details, see here.

• Introduction
  • Installation on Kubernetes
  • Issuer and Certificate
    • Extract CA and certificate

Installation on Kubernetes

chainhead

Introduction

This gist describes an MQTT client writing sensor data to an Server Sent Events (SSE) end-point.

Getting started

git clone https://gist.github.com/chainhead/715e48a2f157e2bfe3f012f587f8bf5b
npm i express mqtt
node server.js

chainhead

Introduction

Installation

• https://www.keycloak.org/docs/latest/server_installation/
• https://medium.com/@hasnat.saeed/setup-keycloak-server-on-ubuntu-18-04-ed8c7c79a2d9
• Ubuntu 18.04, 4 GB RAM
• Pre-requisite: sudo timedatectl set-timezone Asia/Kolkata

Install Java

chainhead

Introduction

This is a short description of how to get git credentials in an EC2 instance set-up for CI/CD scripts. In the following scripts, we do the following:

• Install the AWS CLI. See here for description of steps on Linux.
• Install jq to parse the JSON output from CLI.
• Run the aws CLI for ssm (AWS Systems Manager) to extract parameter values for git user.
• Set the git user name globally.
• Set the name of the script in GIT_ASKPASS that will return the git password.

chainhead

Introduction

This gist shows a basic implementation of a HTTP server that handles the request to upgrade connection to Websockets.

chainhead

Introduction

A basic implementation of logging with Go language. Copied from https://www.honeybadger.io/blog/golang-logging/

Usage

1. Run the following commands to test with built-in log package. Logs will be saved in logs.txt.

go run log.go

chainhead

Introduction

# https://raw.githubusercontent.com/eclipse/mosquitto/master/mosquitto.conf
kubectl create ns/mqtt
kubectl -n mqtt create configmap mosquitto-conf --from-file=mosquitto.conf
kubectl -n mqtt create -f deploy.yaml

chainhead

#!/usr/bin/python
import RPi.GPIO as GPIO
import time
 
#GPIO SETUP
channel = 21
GPIO.setmode(GPIO.BCM)
GPIO.setup(channel, GPIO.IN)
 
def moisture_detect(channel):

chainhead

Introduction

This is a sample Websocket client to send random JSON payload to a Websockets server.

Installation

After cloning this gist, run the following commands.

npm init -y