Introduction

Keycloak – Open Source Identity and Access Management for Modern Applications and Services

Installation

Java

Using AdoptOpenJDK8

brew info adoptopenjdk8

Eclipse

Keycloak

WildFly

See Also

• Awesome Keycloak

Troubleshooting

Change Server Port

By default, executing standalone.sh (for Linux) / standalone.bat (for Windows) makes the server available at following urls:

https://localhost:8443/auth/
http://localhost:8080/auth/

If we need to run multiple instance of server at different ports, run the following command:

For Linux:

standalone.sh -Djboss.socket.binding.port-offset=100

For Windows:

standalone.bat -Djboss.socket.binding.port-offset=100

The above commands will add the offset of 100 to the defaults ports available for Keycloak server.

For example, previously the ports where 8443 and 8000. Now the new ports become 8443 + 100 = 8543 and 8080 + 100 = 8180.

References:

https://www.keycloak.org/docs/3.2/getting_started/topics/secure-jboss-app/before.html

Location of Server Logfile

\standalone\log

Additional Readings

• https://codehumsafar.wordpress.com/category/keycloak/

Introduction

Installation

Install on macOS

$ brew install maven

Maven Commands

Maven Commands

Let’s look into some popular and must know maven commands. We will use a sample Maven project to showcase the command output.

1. mvn clean

This command cleans the maven project by deleting the target directory. The command output relevant messages are shown below.

$ mvn clean
...
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ maven-example-jar ---
[INFO] Deleting /Users/pankaj/Desktop/maven-examples/maven-example-jar/target
...

2. mvn compiler:compile

This command compiles the java source classes of the maven project.

$ mvn compiler:compile
...
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-cli) @ maven-example-jar ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /Users/pankaj/Desktop/maven-examples/maven-example-jar/target/classes
...

3. mvn compiler:testCompile

This command compiles the test classes of the maven project.

$ mvn compiler:testCompile
...
[INFO] --- maven-compiler-plugin:3.8.1:testCompile (default-cli) @ maven-example-jar ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /Users/pankaj/Desktop/maven-examples/maven-example-jar/target/test-classes
...

4. mvn package

This command builds the maven project and packages them into a JAR, WAR, etc.

$ mvn package
...
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ maven-example-jar ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /Users/pankaj/Desktop/maven-examples/maven-example-jar/target/classes
...
-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running com.journaldev.maven.classes.AppTest
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.005 sec

Results :
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

[INFO] 
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ maven-example-jar ---
[INFO] Building jar: .../maven-examples/maven-example-jar/target/maven-example-jar-0.0.1-SNAPSHOT.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
...

The output shows the location of the JAR file just before the “BUILD SUCCESS” message. Notice the package goal executes compile, testCompile, and test goals before packaging the build.

5. mvn install

This command builds the maven project and installs the project files (JAR, WAR, pom.xml, etc) to the local repository.

$ mvn install
...
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ maven-example-jar ---
...
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ maven-example-jar ---
...

6. mvn deploy

This command is used to deploy the artifact to the remote repository. The remote repository should be configured properly in the project pom.xml file distributionManagement tag. The server entries in the maven settings.xml file is used to provide authentication details.

7. mvn validate

This command validates the maven project that everything is correct and all the necessary information is available.

8. mvn dependency:tree

This command generates the dependency tree of the maven project.

$ mvn dependency:tree
...
[INFO] --- maven-dependency-plugin:2.8:tree (default-cli) @ Mockito-Examples ---
[INFO] com.journaldev.mockito:Mockito-Examples:jar:1.0-SNAPSHOT
[INFO] +- org.junit.platform:junit-platform-runner:jar:1.2.0:test
[INFO] |  +- org.apiguardian:apiguardian-api:jar:1.0.0:test
[INFO] |  +- org.junit.platform:junit-platform-launcher:jar:1.2.0:test
...

9. mvn dependency:analyze

This command analyzes the maven project to identify the unused declared and used undeclared dependencies. It’s useful in reducing the build size by identifying the unused dependencies and then remove it from the pom.xml file.

$ mvn dependency:analyze
...
[INFO] --- maven-dependency-plugin:2.8:analyze (default-cli) @ Mockito-Examples ---
[WARNING] Used undeclared dependencies found:
[WARNING]    org.junit.jupiter:junit-jupiter-api:jar:5.2.0:test
[WARNING]    org.mockito:mockito-core:jar:2.19.0:test
[WARNING] Unused declared dependencies found:
[WARNING]    org.junit.platform:junit-platform-runner:jar:1.2.0:test
...

10. mvn archetype:generate

Maven archetypes is a maven project templating toolkit. We can use this command to generate a skeleton maven project of different types, such as JAR, web application, maven site, etc.

Recommended Reading: Creating a Java Project using Maven Archetypes

11. mvn site:site

This command generates a site for the project. You will notice a “site” directory in the target after executing this command. There will be multiple HTML files inside the site directory that provides information related to the project.

12. mvn test

This command is used to run the test cases of the project using the maven-surefire-plugin.

$ mvn test
...
[INFO] --- maven-surefire-plugin:2.22.0:test (default-test) @ Mockito-Examples ---
[INFO] 
[INFO] -------------------------------------------------------
[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running TestSuite
first-element
second-element
Employee setName Argument = Pankaj
...
[INFO] Results:
[INFO] 
[INFO] Tests run: 5, Failures: 0, Errors: 0, Skipped: 0
...

13. mvn compile

It’s used to compile the source Java classes of the project.

$ mvn compile
...
[INFO] --- maven-compiler-plugin:3.7.0:compile (default-compile) @ Mockito-Examples ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent!
[INFO] Compiling 10 source files to /Users/pankaj/Desktop/maven-examples/Mockito-Examples/target/classes
...

14. mvn verify

This command build the project, runs all the test cases and run any checks on the results of the integration tests to ensure quality criteria are met.

Maven Options

Maven provides a lot of command-line options to alter the maven build process. Let’s look at some of the important maven options.

15. mvn -help

This command prints the maven usage and all the available options for us to use.

16. mvn -f maven-example-jar/pom.xml package

This command is used to build a project from a different location. We are providing the pom.xml file location to build the project. It’s useful when you have to run a maven build from a script.

17. mvn -o package

This command is used to run the maven build in the offline mode. It’s useful when we have all the required JARs download in the local repository and we don’t want Maven to look for any JARs in the remote repository.

18. mvn -q package

Runs the maven build in the quiet mode, only the test cases results and errors are displayed.

$ mvn -q package         

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running com.journaldev.maven.classes.AppTest
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.006 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

19. mvn -X package

Prints the maven version and runs the build in the debug mode. It’s opposite of the quiet mode and you will see a lot of debug messages in the console.

mvn -X Debug Mode

20. mvn -v

Used to display the maven version information.

$ mvn -v
Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)
Maven home: /Users/pankaj/Downloads/apache-maven-3.6.3
Java version: 13.0.1, vendor: Oracle Corporation, runtime: /Library/Java/JavaVirtualMachines/jdk-13.0.1.jdk/Contents/Home
Default locale: en_IN, platform encoding: UTF-8
OS name: "mac os x", version: "10.15.1", arch: "x86_64", family: "mac"

21. mvn -V package

This command prints the maven version and then continue with the build. It’s equivalent to the commands mvn -v;mvn package.

22. mvn -DskipTests package

The skipTests system property is used to skip the unit test cases from the build cycle. We can also use -Dmaven.test.skip=true to skip the test cases execution.

23. mvn -T 4 package

This command tells maven to run parallel builds using the specified thread count. It’s useful in multiple module projects where modules can be built in parallel. It can reduce the build time of the project.

See also

• Maven Cheat Sheet

Trobleshooting

Could not find or load main class org.apache.maven.wrapper.MavenWrapperMain

You’re missing the .mvn folder in your git repository. You should have a folder called .mvn which contains the following files

• wrapper/maven-wrapper.jar, wrapper/maven-wrapper.properties
• jvm.config.

Try doing git add -f .mvn from the command line then commit and push.

Here is how to create .mvn directory with needed jar inside.

mvn -N io.takari:maven:wrapper

We can also specify the version of Maven:

mvn -N io.takari:maven:wrapper -Dmaven=3.5.2

Introduction

Installation

Install on macOS

$ brew tap adoptopenjdk/openjdk

Java 8

# Install Java 8
$ brew cask install adoptopenjdk8

# Install Java 11
$ brew cask install adoptopenjdk11

# Install Gradle
$ brew install gradle

# Install Maven
$ brew install maven

Managing different Version

Install jenv and setup

$ brew install jenv

Add java home folder to jenv

$ jenv add /Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home
$ jenv add /Library/Java/JavaVirtualMachines/adoptopenjdk-11.jdk/Contents/Home

Introduction

Spring makes programming Java quicker, easier, and safer for everybody. Spring’s focus on speed, simplicity, and productivity has made it the world’s most popular Java framework.

Required Software

Java

Spring recommend AdoptOpenJDK version 8 or version 11.

Oracle AdoptOpenJDK OpenJDK

Eclipse

Eclipse IDE for Enterprise Java Developers

Sprint Tools | 4

Spring Tools 4 for Eclipse

Create a new App from CLI

Create a starter app using spring.io from the commandline

$ curl https://start.spring.io/starter.zip -d language=java -d dependencies=web,mustache,jpa,h2,devtools -d packageName=com.example.blog -d name=Blog -o blog.zip

Working with Maven

Tipps and Tricks

Change App Port Number

Add line to file src/main/resources/application.properties

server.port=9010

Learning Path

Start with the following tutorials / guides:

• Spring Quickstart Guide
• Building a RESTful Web Service
• Consuming a RESTful Web Service
• Accessing Data with JPA

See Also

• Building a RESTful Web Service
• Consuming a RESTful Web Service
• Consuming a RESTful Web Service with AngularJS
• Consuming a RESTful Web Service with jQuery
• Consuming a RESTful Web Service with rest.js
• Accessing GemFire Data with REST
• Accessing MongoDB Data with REST
• Accessing data with MySQL
• Accessing JPA Data with REST
• Accessing Neo4j Data with REST
• Securing a Web Application
• Building an Application with Spring Boot

• Building REST services with Spring
• React.js and Spring Data REST

• Creating API Documentation with Restdocs
• Enabling Cross Origin Requests for a RESTful Web Service
• Building a Hypermedia-Driven RESTful Web Service
• Circuit Breaker

References

https://github.com/AGWA/git-crypt

https://blog.francium.tech/secure-your-credentials-using-git-crypt-1ccbacc483c7

https://buddy.works/guides/git-crypt

TL;DR

COMMON COMMANDS

git-crypt init
git-crypt status
git-crypt lock

GPG COMMANDS

git-crypt add-gpg-user GPG_USER_ID
git-crypt unlock

SYMMETRIC KEY COMMANDS

git-crypt export-key OUTPUT_KEY_FILE
git-crypt unlock KEY_FILE

Installation

$ brew install git-crypt

Prepare Repository

$ cd <repository>

$ git crypt init
Generating key…

Create .gitattributes file

secretfile filter=git-crypt diff=git-crypt
*.key filter=git-crypt diff=git-crypt
secretdir/** filter=git-crypt diff=git-crypt
.gitattributes !filter !diff # prevent file from encrypted

General Readings

• https://reactjs.org/
• https://reactnative.dev/
• https://facebook.github.io/metro/
• https://expo.io/

Create App

Expo CLI Quickstart

Assuming that you have Node 12 LTS or greater installed, you can use npm to install the Expo CLI command line utility:

npm install -g expo-cli

Then run the following commands to create a new React Native project called “GettingStarted”:

expo init app-getting-started
cd app-getting-started
npm start # you can also use: expo start

React Native CLI Quickstart

npx react-native init app-getting-started

or create new project based on a template

npx react-native init app-getting-started--template react-native-template-typescript

Start App

Step 1: Start Metro

First, you will need to start Metro (Docs), the JavaScript bundler that ships with React Native. Metro “takes in an entry file and various options, and returns a single JavaScript file that includes all your code and its dependencies.”

npx react-native start

Then, visit the Website or the Metro Page (http://localhost:8081/)

Step 2: Start your application

Let Metro Bundler run in its own terminal. Open a new terminal inside your React Native project folder. Run the following:

# For running app on iOS
npx react-native run-ios

# For running app on Android
npx react-native run-android

Installation

Install Python 3

Install Ansible

pip install ansible

Setup virtual machines

In this example, we use Vagrant. But using docker is also a good choice

Create Vagrantfile

Change IP Address and Hostname for each virtual machine

Vagrant.configure("2") do |config|
  config.vm.box = "hashicorp/bionic64"
  config.vm.network "public_network", ip: "172.16.2.191", bridge: "en0: Ethernet"

  config.vm.synced_folder "./data", "/DATA"
  config.vm.hostname = "host1"
end

Start virtual machine

vagrant up
vagrant ssh

Configure virtual machine

Install required programm sshpass for running ansible commands as root on target machines.

sudo apt-get install sshpass

Setup SSH permissions

Create ssh key

ssh-keygen -t rsa

Add id_rsa_<user>.pub to virtual machines into $HOME/.ssh/authorized_keys

Setup config files

etc/ansible/hosts

ansible1
ansible2
ansible3

etc/ansible/ansible.cfg

Create Ansible configuration file in current directory with this content:

[defaults]
interpreter_python = auto

Ansible searches for configuration files in the following order, processing the first file it finds and ignoring the rest:

1. $ANSIBLE_CONFIG if the environment variable is set.
2. ansible.cfg if it’s in the current directory.
3. ~/.ansible.cfg if it’s in the user’s home directory.
4. /etc/ansible/ansible.cfg, the default config file.

First Test

 ansible -i etc/ansible/hosts all -m ping -u vagrant

Set default Python version on Ubuntu

update-alternatives --install /usr/bin/python python /usr/bin/python3.6 1

Working with Playbooks

Create simple playbook

Create file httpd.yaml

---
- hosts: webservers
  remote_user: ansible
  tasks:
  - name: Ensure apache is installed and updated
    yum:
      name: httpd
      state: latest
    become: yes

Run playbook

ansible-playbook -i etc/ansible/hosts  httpd.yaml -kK

Troubleshooting

Allow SSH root login

$ sudo sed -i 's/#PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config

Certifications: 1 2

Azure Solutions Architect Expert

Qualification

• Implementierung von Management- und Sicherheitslösungen
• Implementieren und Überwachen einer Azure-Infrastruktur
• Implementieren Sie Lösungen für Apps
• Implementierung und Verwaltung von Datenplattformen
• Entwurfsüberwachung
• Entwurf Identität und Sicherheit
• Entwerfen eines Datenspeichers
• Entwicklung von Geschäftskontinuität
• Infrastruktur entwerfen

Exams

• AZ-303: Microsoft Azure Architect Technologies
• AZ-304: Microsoft Azure Architect Design

Exams

• AZ-204: Developing Solutions for Microsoft Azure
• AZ-303: Microsoft Azure Architect Technologies

• AZ-304: Microsoft Azure Architect Design

Exam Preparation

• AZ-300 Exam Preparation: Technologies for Microsoft Azure Architects
• AZ-301 Exam Preparation: Designing a Microsoft Azure Architecture

Readings

• How to Become a Microsoft Certified Azure Solutions Architect

Learning Path

AZ-303 / AZ-304

Introduction

NestJS (just Nest from here on out), is a Node framework meant to build server-side applications. Not only is it a framework, but it is also a platform to meet many backend application needs, like writing APIs, building microservices, or doing real-time communications through web sockets.

Nest is also heavily influenced by Angular, and you will immediately find its concepts familiar. The creators of Nest strived to make the learning curve as small as possible, while still taking advantage of many higher level concepts such as modules, controllers, and dependency injection.

Installation

Install NodeJS

Download NodeJS from here and install as described here.

For example, on macOS using Homebrew

brew install node

Or download the package

curl "https://nodejs.org/dist/latest/node-${VERSION:-$(wget -qO- https://nodejs.org/dist/latest/ | sed -nE 's|.*>node-(.*)\.pkg</a>.*|\1|p')}.pkg" > "$HOME/Downloads/node-latest.pkg" && sudo installer -store -pkg "$HOME/Downloads/node-latest.pkg" -target "/"

Install NextJS

npm i -g @nestjs/cli

Create server App

Create new server App

nest new demo.server

Start server App

cd demo.server

npm run start:dev

Now open browser on http: localhost:3000

App Structure

main.ts

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  await app.listen(3000);
}
bootstrap();

app.module.ts

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';

@Module({
  imports: [],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

app.controller.ts

import { Controller, Get } from '@nestjs/common';
import { AppService } from './app.service';

@Controller()
export class AppController {
  constructor(private readonly appService: AppService) {}

  @Get()
  getHello(): string {
    return this.appService.getHello();
  }
}

app.service.ts

import { Injectable } from '@nestjs/common';

@Injectable()
export class AppService {
  getHello(): string {
    return 'Hello World!';
  }
}

Add Functionality

Create service and controller

nest g service missions
nest g controller missions

Modify mission service

@Injectable()
export class MissionsService {
  missions: Mission[] = [
    { id: 1, title: 'Rescue cat stuck in asteroid', reward: 500, active: true, },
    { id: 2, title: 'Escort Royal Fleet', reward: 5000, active: true, },
    { id: 3, title: 'Pirates attacking the station', reward: 2500, active: false, },
  ];

  async getMissions(): Promise<Mission[]> {
    return this.missions;
  }
}

Modify mission controller

@Controller('missions')
export class MissionsController {
  constructor(private missionsService: MissionsService) {}

  @Get()
  getMissions() {
    return this.missionsService.getMissions();
  }
}

Open in browser: http://localhost:3000

Create Frontend App

Create new frontend App

ionic start demo.frontend sidemenu

Working with Database and TypeORM

Create / Sync database with schema

Add command to package.json

"scripts": {
    "typeorm": "ts-node -r tsconfig-paths/register ./node_modules/typeorm/cli.js"
}

npm run typeorm schema:sync

TypeORM Commands

schema:sync         
Synchronizes your entities with database schema. It runs schema update queries on all connections you have. To run update queries on a concrete connection use -c option.
schema:log          
Shows sql to be executed by schema:sync command. It shows sql log only for your default connection. To run update queries on a concrete connection use -c option.
schema:drop         
Drops all tables in the database on your default connection. To drop table of a concrete connection's database use -c option.
query               
Executes given SQL query on a default connection. Specify connection name to run query on a specific connection.
entity:create       
Generates a new entity.
subscriber:create   
Generates a new subscriber.
migration:create    
Creates a new migration file. [Aliase: migrations:create]
migration:generate  Generates a new migration file with sql needs to be executed to update schema. [Aliase: migrations:generate]
migration:run       
Runs all pending migrations. [Aliase: migrations:run]
migration:show      
Show all migrations and whether they have been run or not
migration:revert    
Reverts last executed migration. [Aliase: migrations:revert]
version             
Prints TypeORM version this project uses.
cache:clear         
Clears all data stored in query runner cache.
init                
Generates initial TypeORM project structure. If name specified then creates files inside directory called as name. If its not specified then creates files inside current directory.

Additional readings

• Full-Stack TypeScript with Ionic, Angular, and NestJS Part 1
• Nest.js Tutorial: Build your First REST API CRUD App with TypeORM/
• NestJS TypeORM Pagination – Step By Step Guide/
• Getting started with NestJS & TypeORM (+bonus NestJS Admin)
• TypeORM With NEST JS Basic Tutorial
• Learning nestjs I
• NestJS, TypeORM and PostgreSQL — full example development and project setup working with database migrations.

Installation Overview

NodeJS

Angular

Ionic

Install

npm install -g @ionic/cli

Create App

ionic start Getting-Started tabs --type react

Start App

ionic serve

React / ReactJS

Install

React Native

Stencil

npm init stencil
npm install --save-exact @stencil/core@latest 
npm install --save-dev @types/jest@26.0.12 jest@26.4.2 jest-cli@26.4.2 
npm install --save-dev @types/puppeteer@3.0.1 puppeteer@5.2.1
npm test
npm start

Gatsby

NextJS

NestJS

Usefull Libraries

More to read

• https://medium.com/better-programming/heres-a-list-of-top-css-front-end-libraries-eb0330c04148