100 Days of DevOps: Day 70

Installing Git and GitLab Plugins on Jenkins via the UI

Overview

As part of the Nautilus DevOps setup, I configured a new Jenkins server to handle CI/CD jobs.
The initial goal was to install two essential plugins — Git and GitLab — which allow Jenkins to integrate with source control systems for continuous integration.

During installation via the Jenkins UI, I ran into several dependency errors, but eventually discovered that a simple Jenkins restart solved the issue completely.

Step 1: Accessing Jenkins

I started by logging in to Jenkins through the web interface:

Login credentials:

• Username: admin
• Password: Adm!n321

Once logged in, the Jenkins dashboard appeared — the starting point for all administrative actions.

Step 2: Navigating to Plugin Manager

From the left-hand sidebar, I selected:

Manage Jenkins → Plugins

This opened the Jenkins Plugin Manager, where plugins can be installed, updated, or removed.
I switched to the Available plugins tab and searched for:

• Git
• GitLab

I selected both and clicked Install without restart to begin installation.

Step 3: Encountering the Installation Errors

While the installation began, several red error messages appeared:

Failed to load: Jenkins Git client plugin (git-client 6.2.1)
 - Failed to load: Mina SSHD API :: Common (mina-sshd-api-common)

and later:

Failed to load: Mina SSHD API :: Common
 - Update required: BouncyCastle API Plugin to version 2.30.1.80 or higher

At first, this looked like a dependency issue — as if Jenkins was missing a required plugin.
However, after checking the Installed Plugins tab, I noticed that the BouncyCastle API plugin was already installed.

Step 4: The Fix — Restart Jenkins

Instead of downloading anything manually, I decided to try a restart directly from the Jenkins UI.

To do this, I navigated to:

Manage Jenkins → Restart Jenkins when installation is complete and no jobs are running

Jenkins restarted automatically.
After waiting for the login page to reappear, I signed in again and returned to the Plugin Manager.

Step 5: Reinstalling Plugins After Restart

Once Jenkins was back online, I retried the installation:

Manage Jenkins → Plugins → Available tab

I searched again for Git and GitLab, selected both, and clicked Install without restart.

This time, the installation completed successfully, with all plugins showing green checkmarks and no errors.

Step 6: Verification

After the installation finished, I went to:

Manage Jenkins → Plugins → Installed tab

I confirmed the following plugins were now active:

• Git plugin
• Git Client plugin
• Mina SSHD API Common
• BouncyCastle API plugin
• GitLab plugin

All dependencies were properly loaded after the restart.

Step 7: Outcome

• Jenkins now has Git and GitLab plugins installed and working.
• All dependency errors resolved through a simple UI restart.
• The environment is ready for setting up CI/CD pipelines and GitLab webhooks.