====================
Nexus Repository
====================

=> Nexus is called as Artifactory Server.

=> It is used to store project artifacts (jar/war files) as backup.

=> It is also used as Maven Remote Repository.

=> Remote Repositories are used to store shared libraries (jars).

=> Shared libs means the jars which are required for several projects in the same company

Note: In realtime, every company will have their own remote repository.

=================
Nexus vs Git Hub
=================

=> Git Hub is used as version control system 
=> Git Hub is used for storing project source code

=> Nexus is used as artifactory server
=> Nexus is used for storing project build artifacts & shared libs


==========================
Nexus Setup using Docker
=========================

URL : https://github.com/ashokitschool/DevOps-Documents/blob/main/07-Nexus-Setup-Docker.md

==========================================
Configure Nexus Server details in maven
==========================================

-> Add nexus server details in maven settings.xml file

		<server>
			<id>nexus</id>
			<username>admin</username>
			<password>admin</password>
		</server>

=============================================
How to upload project artifact into Nexus ?
=============================================

=> When we package our maven application it will generate a jar / war file. That jar/war is called as project build artifact.

=> Project build artifacts we will store into nexus for backup purpose.

=> To store project artifacts we will create nexus repositories.

=> We have 2 types repositories in nexus to store build artifacts.

		1) snapshot repository

		2) release repository

-> If project is under development then that project build artifacts will be stored into snapshot repository.

-> If project development completed and released to production then that project build artifacts will be stored to release repository.

=> Create Two Repositories one as snapshot and another one as release.

	Snapshot Repo URL : http://3.109.184.254:8081/repository/ashokit-snapshot-repo/

	Release Repo URL : http://3.109.184.254:8081/repository/ashokit-release-repo/

-> Nexus Repository details we will configure in project pom.xml  file like below

<distributionManagement>  

	<repository>
		<id>nexus</id>
		<name>Ashok IT Releases Nexus Repo</name>
		<url>http://3.109.184.254:8081/repository/ashokit-release-repo/</url>
	</repository>
	
	<snapshotRepository>
		<id>nexus</id>
		<name>Ashok IT Snapshots Nexus Repo</name>
		<url>http://3.109.184.254:8081/repository/ashokit-snapshot-repo/</url>
	</snapshotRepository>	

</distributionManagement>


-> Once these details are configured then we can run below maven goal to upload build artifacts to Nexus Server.

	$ mvn clean deploy

Note: When we execute maven deploy goal, internally it will execute 'compile + test + package + install + deploy' goals.	


Note: Based on <version/> name available in project pom.xml file it will decide artifacts should be stored to which repository.

<version>0.0.1-SNAPSHOT</version> : Upload to snapshot repository

<version>0.0.1-RELEASE</version> : Upload to release repository


==================
Remote Repository 
=================

-> Remote repository used for maintaining shared libraries (common jars required for multiple projects)

-> If we want to use few jar files in multiple projects in the company then we will use Remote Repository to store those jars (libraries).

-> Remote repository is specific to our company projects.

=======================================
Create Remote Repo and Upload Jar file
=======================================

-> Go to Settings
-> Go to Repositories
-> Create New Repository
-> Choose Maven (Hosted) Repository
-> Give a name for Repository (Ex: ashokit-remote-repository) & Complete the process

Note: With above steps Remote Repository got created.

Remote Repo URL : http://3.109.184.254:8081/repository/ashokit-remote-repo/	

=> Now upload jar file into remote repository

	-> Go to BrowseSection
	-> Select Remote Repository (By default it is empty)
	-> Click on Upload Component
	-> Upload Jar file and give groupId, artifactId and Version		

		groupId : in.ashokit
		artifactId : pwd-utils
		version : 1.0	

-> Take dependency details of uploaded jar file and add in project pom.xml as a dependency like below

<dependency>
  <groupId>in.ashokit</groupId>
  <artifactId>pwd-utils</artifactId>
  <version>1.0</version>
</dependency>

> We need to add Remote Repository Details in pom.xml above <dependencies/> tag

	<repositories>
		<repository>
			<id>nexus</id>
			<url>http://3.109.184.254:8081/repository/ashokit-remote-repo/</url>
		</repository>
	</repositories>		

-> After adding the remote repository details in pom.xml then execute maven package goal and see dependency is downloading from nexus repo or not.

		$ mvn clean package


=========================================
How to resolve HTTP Mirror Block Issue ?
=========================================

=> Make below change in maven settings.xml

<mirror>
      <id>maven-default-http-blocker</id>
      <mirrorOf>dummy</mirrorOf>
      <name>Pseudo repository to mirror external repositories initially using HTTP.</name>
      <url>http://0.0.0.0/</url>
      <blocked>false</blocked>
</mirror>

===================
Nexus Summary
===================

1) What is Nexus and Why we need to go for Nexus ?

2) How to setup Nexus Server using Docker

3) How to create Repositories in Nexus (snapshot & release)

4) How to upload build artifacts into Nexus Repositories

5) What are Shared Libraries ?

6) How to create Remote Repository ?

7) How to upload Shared Libraries into remote repository

8) How to configure remote repository in pom.xml file

9) Download shared libraries from Remote Repository.