SahanaJSJ sahanasj

Building Docker image with Packer and provisioning with Ansible

Overview

Packer

Packer is used to build image from a base image, perform provisions and store (commit) the final image.
We use provisioners and Packer templates to do the actual work to create the final image.
We use Ansible for provisioning.

Building Docker image with Packer and provisioning with Ansible

Overview

Packer

Packer is used to build image from a base image, perform provisions and store (commit) the final image.
We use provisioners and Packer templates to do the actual work to create the final image.
We use Ansible for provisioning.

List of Linux networking tools

netstat (ss)

Displays contents of /proc/net files. It works with the Linux Network Subsystem, it will tell you what the status of ports are ie. open, closed, waiting, masquerade connections. It will also display various other things. It has many different options. Netstat (Network Statistic) command display connection info, routing table information etc. To displays routing table information use option as -r.

Sample output:

Proto Recv-Q Send-Q  Local Address          Foreign Address        (state)    
tcp4 0 0 127.0.0.1.62132 127.0.0.1.http ESTABLISHED

	spring:
	datasource:
	type: com.zaxxer.hikari.HikariDataSource
	hikari:
	idle-timeout: 10000
	platform: mysql
	username: ${DB_USERNAME}
	password: ${DB_PASSWORD}
	url: jdbc:mysql://${DB_HOST}/${DB_NAME}
	jpa:

	FROM openjdk:10-jre-slim
	RUN mkdir -p /opt/to-do-app/
	COPY ./target/to-do-listEntity-app-0.0.1-SNAPSHOT.jar /opt/to-do-app/
	WORKDIR /opt/to-do-app/
	EXPOSE 8080
	CMD ["java", "-jar", "to-do-listEntity-app-0.0.1-SNAPSHOT.jar"]

	FROM node:7.7-alpine

	# install dependencies
	ADD package.json /tmp/package.json
	RUN cd /tmp && npm install

	# Copy dependencies
	RUN mkdir -p /opt/to-do-app && cp -a /tmp/node_modules /opt/to-do-app

	# Setup workdir

	# Define 'Service' to expose backend application deployment
	apiVersion: v1
	kind: Service
	metadata:
	name: to-do-app-backend
	spec:
	selector: # backend application pod lables should match these
	app: to-do-app
	tier: backend
	ports:

	# Define 'Service' to expose FrontEnd Application
	apiVersion: v1
	kind: Service
	metadata:
	name: to-do-app-frontend
	spec:
	selector: # pod labels should match these
	app: to-do-app
	tier: frontend
	ports:

	# ConfigMap to expose configuration related to backend application
	apiVersion: v1
	kind: ConfigMap
	metadata:
	name: backend-conf # name of configMap
	data:
	server-uri: 34.66.207.42 # enternal ip of backend application 'Service'

	# Terminal Cheat Sheet

	pwd # print working directory
	ls # list files in directory
	cd # change directory
	~ # home directory
	.. # up one directory
	- # previous working directory
	help # get help
	-h # get help