DevOps Classroom Series – 09/May/2020

Day Builds and Night Builds

  • The trigger to Start CI/CD will be
    • A Schedule (Every day at 7:00 AM )
    • Whenever developer commits code
  • Whenever above events are triggered we should start ci/cd, so any ci/cd engine will start its journey for Version Control System to Production Systems. The whole steps are called as pipelines.
  • Lets look at popular steps in the order of execution in a Typical Continuous Delivery Pipeline
    • Developer Pushes the code to Git

    • Build the Code

      • This is very much dependent on Development Language
        • C => Make, GCC
        • Java => Ant, Maven, Gradle
        • .net => MSBuild, dotnet build
        • Generic tools: buildbot etc
        • Container => Docker Image Build
    • Test the Code using Unit Tests written by Dev Teams

      • Running Unit Tests (JUnit, MSTest, Pytest, Jasmine)
    • Create a Package

    • Create all the possible test Environments (QA, SystemTest, PerformanceTest) and deploy the package to the respective Environment and Execute tests

      • To Create Environment we use
        • InfraProvisioning (Terraform)
        • Configuration Management (Ansible)
        • Orchestration (Kubernetes)
      • Automated System Tests and Performance tests are triggered from Jenkins
        • Selenium
        • JMeter
        • Karate
    • Gather all the Test Results and Give Feedback

Maven Installation

  • Windows:
  • MAC:
    • Use homebrew to install mac
  • Ubuntu:
    sudo apt-get update
    sudo apt-get install maven -y
    
  • Centos/Redhat: Refer Here

Scenario-1: Java Web Application without much knowledge of build

  • Preparation:

    • Fork the Spring Pet Clinic Project from here Preview
    • My repo is located at here
  • Target:

    • We need to Create a package for the Java Code and this needs to be generated whenever developer pushes the commit
  • Implementation

    • Create a freestyle project Preview Preview Preview Preview Preview

    • Both PollSCM and schedule uses cron syntax to schedule the job and poll time. You can use cron generators as shown Preview Preview

    • Developer has asked you to install maven3 and execute “`mvn package“

    • Installing maven on ubuntu machine

    sudo apt-get install maven -y
    
    • Configure Build as shown below and save the project (Wait for build or do manual) Preview

Maven

  • Maven is a Popular tool and known for Java and Java Based Languages.

    • Builds
    • Dependency Management
    • Reporting
    • Documentation
    • Release Management
  • Prior to Maven, Java Projects used to use a tool called as Ant to build the projects. ANT is a configuration based tool.

  • In ANT to Build the code

    • Configure Build file
    • Add configuration in XML file with target Sections Refer Here
  • Maven had wonderful dependency resolution and followed a convention approach. (Convention over Configuration)

Maven Model

  • Project Object Model (POM) is used to manage projects build, reporting, dependencies and dcumentation.

  • Convention Over Configuration:

    • Every Maven Project starts with pom.xml => Projects base directory => ${project-dir}
    • Java Code => ${project-dir}/src/main/java
    • Groovy Code => ${project-dir}/src/main/groovy
    • Scala Code => ${project-dir}/src/main/scala
    • Resources => ${project-dir}/src/main/resources
    • Tests => ${project-dir}/src/test
    • Folder for Packages and Classes => ${project-dir}/target
  • Lets Create a Simple Java Project

    • Create a directory hello-maven
    mkdir hello-maven
    cd hello-maven
    touch pom.xml
    
    • Copy the following content into pom.xml
    <?xml version="1.0" encoding="UTF-8"?>
    <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://maven.apache.org/POM/4.0.0"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.qualitythought.devops</groupId>
    <artifactId>hello-maven</artifactId>
    <version>1.0</version>
    
    </project>
    
    
    • Create a directory tree as mentioned below and create a file Application.java
    mkdir src
    mkdir src/main
    mkdir src/main/java
    touch src/main/java/Application.java
    
    • Copy the following code into Application.java
    class Application {
        public static void main(String args[]) {
            System.out.println("Hello World Continues");
        }
    }
    
    
    • navigate to projects base directory and execute “`mvn package“
  • Maven Phases:

    • compile: This creates class files by compiling Java Code. To execute this phase mvn compile Preview
    • Test: This Phase executes the unit tests. To execute use mvn test
    • package: This Phase creates the Java Package (JAR/WAR/EAR) mvn package Preview
    • install
    • Deploy
    • clean: Will Remove Target folder Preview
  • Maven Dependencies:

    • When developers develop applications they will use lot of libraries which are defined as dependencies in pom.xml
    • So change pom.xml in the hello-maven/pom.xml to
    <?xml version="1.0" encoding="UTF-8"?>
    <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://maven.apache.org/POM/4.0.0"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.qualitythought.devops</groupId>
    <artifactId>hello-maven</artifactId>
    <version>1.0</version>
    
    <dependencies>
        <dependency>
        <groupId>com.google.guava</groupId>
        <artifactId>guava</artifactId>
        <version>29.0-jre</version>
        </dependency>
        
        
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>
    
    </dependencies>
    
    </project>
    
    
    • Now execute mvn compile and Maven tries to download dependencies for this it has a repository system Preview

    • Repositories in Maven Preview

    • Local Repository:

      • Generally present in HOME_DIRECTORY/.m2 folder and can be changed with Environmental Variable M2_HOME
    • Central Repository:

    • Remote Repository:

      • Hosted with in Organization to resolve dependencies, Organizations use Artifactory(JFrog), Nexus Softwares for Remote Repository
    • In Maven we configure the builds using pom. With POM we need to understand the concept of Super POM and effective POM

    • Super POM is Mavens Default POM. ALL POM inherit from default.

    • While building any project have a look at effective pom by executing mvn help:effective-pom . Below is effective pom of the hello-maven

<?xml version="1.0" encoding="UTF-8"?>
<!-- ====================================================================== -->
<!--                                                                        -->
<!-- Generated by Maven Help Plugin on 2020-05-09T04:23:58Z                 -->
<!-- See: http://maven.apache.org/plugins/maven-help-plugin/                -->
<!--                                                                        -->
<!-- ====================================================================== -->
<!-- ====================================================================== -->
<!--                                                                        -->
<!-- Effective POM for project                                              -->
<!-- 'com.qualitythought.devops:hello-maven:jar:1.0'                        -->
<!--                                                                        -->
<!-- ====================================================================== -->
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.qualitythought.devops</groupId>
  <artifactId>hello-maven</artifactId>
  <version>1.0</version>
  <dependencies>
    <dependency>
      <groupId>com.google.guava</groupId>
      <artifactId>guava</artifactId>
      <version>29.0-jre</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-java8</artifactId>
      <version>5.4.15.Final</version>
      <scope>compile</scope>
    </dependency>
  </dependencies>
  <repositories>
    <repository>
      <snapshots>
        <enabled>false</enabled>
      </snapshots>
      <id>central</id>
      <name>Central Repository</name>
      <url>https://repo.maven.apache.org/maven2</url>
    </repository>
  </repositories>
  <pluginRepositories>
    <pluginRepository>
      <releases>
        <updatePolicy>never</updatePolicy>
      </releases>
      <snapshots>
        <enabled>false</enabled>
      </snapshots>
      <id>central</id>
      <name>Central Repository</name>
      <url>https://repo.maven.apache.org/maven2</url>
    </pluginRepository>
  </pluginRepositories>
  <build>
    <sourceDirectory>/home/ubuntu/hello-maven/src/main/java</sourceDirectory>
    <scriptSourceDirectory>/home/ubuntu/hello-maven/src/main/scripts</scriptSourceDirectory>
    <testSourceDirectory>/home/ubuntu/hello-maven/src/test/java</testSourceDirectory>
    <outputDirectory>/home/ubuntu/hello-maven/target/classes</outputDirectory>
    <testOutputDirectory>/home/ubuntu/hello-maven/target/test-classes</testOutputDirectory>
    <resources>
      <resource>
        <directory>/home/ubuntu/hello-maven/src/main/resources</directory>
      </resource>
    </resources>
    <testResources>
      <testResource>
        <directory>/home/ubuntu/hello-maven/src/test/resources</directory>
      </testResource>
    </testResources>
    <directory>/home/ubuntu/hello-maven/target</directory>
    <finalName>hello-maven-1.0</finalName>
    <pluginManagement>
      <plugins>
        <plugin>
          <artifactId>maven-antrun-plugin</artifactId>
          <version>1.3</version>
        </plugin>
        <plugin>
          <artifactId>maven-assembly-plugin</artifactId>
          <version>2.2-beta-5</version>
        </plugin>
        <plugin>
          <artifactId>maven-dependency-plugin</artifactId>
          <version>2.8</version>
        </plugin>
        <plugin>
          <artifactId>maven-release-plugin</artifactId>
          <version>2.5.3</version>
        </plugin>
      </plugins>
    </pluginManagement>
    <plugins>
      <plugin>
        <artifactId>maven-clean-plugin</artifactId>
        <version>2.5</version>
        <executions>
          <execution>
            <id>default-clean</id>
            <phase>clean</phase>
            <goals>
              <goal>clean</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <artifactId>maven-resources-plugin</artifactId>
        <version>2.6</version>
        <executions>
          <execution>
            <id>default-testResources</id>
            <phase>process-test-resources</phase>
            <goals>
              <goal>testResources</goal>
            </goals>
          </execution>
          <execution>
            <id>default-resources</id>
            <phase>process-resources</phase>
            <goals>
              <goal>resources</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <artifactId>maven-jar-plugin</artifactId>
        <version>2.4</version>
        <executions>
          <execution>
            <id>default-jar</id>
            <phase>package</phase>
            <goals>
              <goal>jar</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.1</version>
        <executions>
          <execution>
            <id>default-compile</id>
            <phase>compile</phase>
            <goals>
              <goal>compile</goal>
            </goals>
          </execution>
          <execution>
            <id>default-testCompile</id>
            <phase>test-compile</phase>
            <goals>
              <goal>testCompile</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.12.4</version>
        <executions>
          <execution>
            <id>default-test</id>
            <phase>test</phase>
            <goals>
              <goal>test</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <artifactId>maven-install-plugin</artifactId>
        <version>2.4</version>
        <executions>
          <execution>
            <id>default-install</id>
            <phase>install</phase>
            <goals>
              <goal>install</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <artifactId>maven-deploy-plugin</artifactId>
        <version>2.7</version>
        <executions>
          <execution>
            <id>default-deploy</id>
            <phase>deploy</phase>
            <goals>
              <goal>deploy</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <artifactId>maven-site-plugin</artifactId>
        <version>3.3</version>
        <executions>
          <execution>
            <id>default-site</id>
            <phase>site</phase>
            <goals>
              <goal>site</goal>
            </goals>
            <configuration>
              <outputDirectory>/home/ubuntu/hello-maven/target/site</outputDirectory>
              <reportPlugins>
                <reportPlugin>
                  <groupId>org.apache.maven.plugins</groupId>
                  <artifactId>maven-project-info-reports-plugin</artifactId>
                </reportPlugin>
              </reportPlugins>
            </configuration>
          </execution>
          <execution>
            <id>default-deploy</id>
            <phase>site-deploy</phase>
            <goals>
              <goal>deploy</goal>
            </goals>
            <configuration>
              <outputDirectory>/home/ubuntu/hello-maven/target/site</outputDirectory>
              <reportPlugins>
                <reportPlugin>
                  <groupId>org.apache.maven.plugins</groupId>
                  <artifactId>maven-project-info-reports-plugin</artifactId>
                </reportPlugin>
              </reportPlugins>
            </configuration>
          </execution>
        </executions>
        <configuration>
          <outputDirectory>/home/ubuntu/hello-maven/target/site</outputDirectory>
          <reportPlugins>
            <reportPlugin>
              <groupId>org.apache.maven.plugins</groupId>
              <artifactId>maven-project-info-reports-plugin</artifactId>
            </reportPlugin>
          </reportPlugins>
        </configuration>
      </plugin>
    </plugins>
  </build>
  <reporting>
    <outputDirectory>/home/ubuntu/hello-maven/target/site</outputDirectory>
  </reporting>
</project>

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