DevOps Classroomnotes 16/Jul/2023

Dependencies

• Whenever a software project is developed, they have lot of dependencies
• before building the code, dependencies have to be present locally
• To manage these dependencies, every programming language has some kind of package manager
  • dotnet: nuget is the package manager
    • packages.config/packages.json
  • java: maven can handle package management
  • python: pip is the package manager
  • nodejs: npm can handle package management
• Scope of Work
  

Maven

• Maven is a tool which can be use to build, package, distribute, test and generate documentation for java and java based languages
• Maven follows convention over configuration
• The maven uses a file called as pom.xml
• pom (Project object model)
• Maven Installation:

# install java 17
sudo apt update
sudo apt install openjdk-17-jdk -y

• Lets try installing maven 3.9.3 Refer Here

cd /tmp
wget https://dlcdn.apache.org/maven/maven-3/3.9.3/binaries/apache-maven-3.9.3-bin.tar.gz
sudo mkdir /usr/share/maven
sudo tar -xvzf apache-maven-3.9.3-bin.tar.gz -C /usr/share/maven
# add /usr/share/maven/apache-maven-3.9.3/bin to the PATH variable
# add to ~/.bashrc or /etc/environment
mvn --version

* Maven goals Refer Here
* validate: validates the pom and its project
* compile: this converts the java code into byte code (.java to .class). It stores the class files in target/classes
* test: it will run the unit tests written and generates test results in xml format in text format. folder will be /target/surefire-reports/TEST-*.xml
* package: This creates the packaging format (jar/war/ear). will be <artifact-id>-<version>.<packaging-format>
* install: This copies the package and its definition into M2_HOME or ~/.m2/repository
* deploy: copying package and its definition to remote repository for other users in other systems to use what you have built
* clean: clean removes target folder
* Lifecycle Refer Here
* To execute any lifecycle goal mvn <goal>
* We have written a simple pom

<project>
  <modelVersion>4.0.0</modelVersion>
  <groupId>io.learningthoughts.samples</groupId>
  <artifactId>hello-maven</artifactId>
  <version>1.0.0-SNAPSHOT</version>
  <properties>
     <maven.compiler.source>11</maven.compiler.source>
     <maven.compiler.target>11</maven.compiler.target>
  </properties>
  <dependencies>
    <dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.13.2</version>
    <scope>test</scope>
   </dependency>
  </dependencies>
</project>

• Maven packaging formats: Refer Here
• Maven goals downloads dependencies and stores in
  • M2_HOME where ever this environment variable points to and if not found does in <home-dir>/.m2

Exercise

• Try installing maven as mentioned above
• Create a simple jenkins project
• build steps:

git clone https://github.com/spring-projects/spring-petclinic.git
cd spring-petclinic && mvn package

Terms

• Artifact => For generating artifacts we use build tools msbuild, maven/gradle
• unit test => junit, mstest/nunit, pytest, jasmine, mocha, most ci cd systems understand junit xml reports to generate test results
• code coverage => we do this from sonar qube
• Static Code Analysis => we do this from sonar qube
• artifact repository => we would use jfrog (azure artifacts)