How to generate report to list unused dependencies in Maven

In this post, we will see how to generate a report to list the unused dependencies of a Java project built using Maven.

We will use the dependency plugin to do so. Let's use the dependency:analyze-report goal as below

mvn dependency:analyze-report -DignoreNonCompile=true

This will basically generate an HTML report containing the list of dependencies with the following classification :

• used and declared.
• used and undeclared.
• unused and declared.

Ideally, it's always a good idea to cleanup the pom's by removing and/or commenting the unused but declared dependencies.

How to deploy specific file to Artifactory using Maven from Jenkins

This post will be helpful in a scenario where you are required to deploy i.e upload just a specific individual file (eg: xyz.zip or abc.jar) to Artifactory using Maven from Jenkins.

For illustration, configure a deploy-file job in Jenkins and add the following Maven goal.

clean deploy:deploy-file
-DgroupId=com.company.abc.message -DartifactId=message -Dversion=${version}
-DgeneratePom=false
-Dpackaging=jar
-DrepositoryId=artifactory
-Durl=http://17.16.18.12:8080/artifactory/simple/libs-release-local/
-Dusername=admin -Dpassword=admin-password
-Dfile=C:\Users\ironcladzone\Desktop\messageTest\message-${version}.jar

This will basically upload the message jar with a dynamically passed version parameter. Assuming the ${version} parameter value is defined 5.3.2 in Jenkins, the above command will essentially deploy message-5.3.2.jar to the libs-release-local repository.

Ciao!

Version increment and/or update using Maven

In today's fresh post, we will look into how to increment and/or update version numbers in pom.xml of your project using Maven.

Let's assume your project has a multi-module/multi-component setup. Each of the module/component has its own pom.xml with a list of dependencies and the overall bill of materials in general.

As a good practice, it's always a good idea to have about 2 pom's on the topmost levels. 1st pom should have all the project dependencies, which will be the parent pom of all modules. The 2nd pom should contain all third party non-project dependencies. This 2nd toplevel pom should be the parent of the 1st toplevel pom. These 2 toplevel pom's collectively define the project and 3rd party dependencies. Note that the versions of all dependencies should be defined in these 2 pom's. The individual module pom's should not carry the version number of dependencies. It will fetch them from the above 2 toplevel pom's.

Also, the module's own version should not be explicitly defined within it's own pom. It should only carry the version of it's parent pom. The below diagram should you help you visualize the ideal structure.

Let's say for instance the current version in current sprint is 5.3.3-7 and you want to update the version to 5.3.4-1 for going on to the next sprint. The following command can get that job done.

• mvn versions:set -DnewVersion=5.3.4-1

Refer the following maven versions plugin page for information.

Note however, that if your source code is under version control (for eg: IBM Clearcase), you may want to check out the files first, then update the versions in pom.xml and then check them in. In such a scenario, use the following sequence of commands to do so :

• cleartool find . -name pom.xml -exec "cleartool co -nc %CLEARCASE_PN%"

This will recursively checkout all pom.xml files within your Clearcase view.

• mvn versions:set -DnewVersion=5.3.4-1

This will increment all pom versions to 5.3.4-1

• cleartool find . -name pom.xml -exec "cleartool ci -nc %CLEARCASE_PN%"

Once the versions are updated, all you have to do is recursively checkin all the pom.xml's. The above command will do that. 

Please note that the above cleartool commands will only work if you're using IBM Clearcase for source control.

For any questions, queries or discussion's kindly drop a comment or two. Peace. Cheers!

How to manually install a plugin in Jenkins

Sometimes in corporate environments, accessing certain things from the internet is blocked by the firewall due to restricted access. In case if you ever come across such a scenario, wherein you are not able to install a plugin in Jenkins due to firewall and/or proxy issue, you always have a workaround to manually install the plugin.

Firstly go to the specific plugin page and download it. For instance, consider the Email-ext plugin page for Jenkins and download it. It will have .hpi extension.

Now go the plugins configuration in Jenkins i.e Manage Jenkins => Manage Plugins => Advanced.
Here you'll see the option to upload the plugin .hpi file

Hope it helps. Cheers!

Print Area of a circle using Python

Let us write a small program today to print the area of circle in Python. The program will accept user input in the form of radius of the circle. There is a constant pi whose value we will be set to 3.142

Code :

print ('Program to calculate area of circle \n')

pi = 3.142
r = float(input('Enter radius : '))

a = pi*(r**2)

print ('Area of circle :', a )

Output :

OR

How to get username from IP address of remote computer

On a network (Home LAN or WiFi or corporate intranet), it is possible to get username from the assigned IP address of a remote machine. Assuming you have a bunch of users using Windows machines on the same network, lets look into the windows command to get the username.

For example, type the following in command prompt :

wmic.exe /node:17.16.15.28 computersystem get username
UserName
IRONCLADZONE\Special.User

Note that this works only for the remote machines which are connected on the same network.

Customized Build email notifications in Jenkins

When using Jenkins for automated builds, as most of you guys may be aware, we can setup SMTP settings for email notifications of build related events. We will cover the topic of SMTP setup in another separate post. In this post, let us just stick to the email customization part. Note that the SMTP settings must be configured in Jenkins for this plugin to work smoothly. For customized email notifications, we will use the Email-ext plugin to replace the default Jenkins'email settings.

With this plugin, we can setup email settings for various trigger conditions like a successful build, aborted build or a build failure etc.

In today's illustration, we'll cover the notification for Failure - Any trigger. In other words, Jenkins will fire a notification the moment there is any kind of build failure. We will use the HTML formatting in the notification. Use the following variables in the job configuration as shown in below screenshot.

In the Content field, try the following piece of code as below :

As you see, we include information like the Jenkins job URL, the cause of the failure which will be a short description of the error, the changes that went into the build and a link to the console URL.

Note the line which includes a regex - we basically do a simple pattern matching i.e we look for the words "BUILD FAILURE" and then display only that part from the build error. In better words, we truncate the verbose build log and show only the relevant error information in the mail notification.

${BUILD_LOG_REGEX, regex="^.*?BUILD FAILURE.*?$", linesAfter=10, matchedLineHtmlStyle="width:100%", showTruncatedLines="false", defaultValue="For detailed information, please check job console link below to find cause of failure"}  

Apart from this, the plugin also allows us to optionally attach the build log. However note that the build logs usually tend to be of big sizes (depending on the size of the project) and could fill your mailboxes fast.

Now with the email notification configured, let us look into how the notifications will actually look like. So here's the output - check the screenshot below :

Signing out for now. Hope it helps. Ciao guys!