🦊 Module 3: GitLab for Network Teams

Familiarize yourself with the GitLab interface.

1. Open GitLab in the browser (URL from the instructor)
2. Create a new project:
   • Click on New project
   • Select Create blank project
   • Name: network-config-YOURNAME
   • Visibility: Private
   • ✅ Enable "Initialize repository with a README"
3. Explore the project:
   • Open Repository → Files
   • Check out Repository → Commits
   • Open Settings → General
4. Clone the project:

   Open PowerShell and navigate to your Desktop:

   📋 Copycd C:\Users\admin\Desktop
   
   # Disable SSL verification (self-signed certificate)
   git config --global http.sslVerify false
   
   # Copy the HTTPS URL from GitLab (Clone button)
   git clone https://198.18.133.100/gitlab-instance-668e631e/network-config-YOURNAME.git
   cd network-config-YOURNAME
   dir

   ⚠️Self-Signed Certificate

   The lab GitLab uses a self-signed certificate. The command git config --global http.sslVerify false is necessary so that Git accepts the HTTPS connection.

Update the existing README with a meaningful project description.

1. Edit README.md:

   The file README.md already exists in the project foldernetwork-config-YOURNAME (it was created along with the project). Open it in VS Code and replace the content with the following:

   📄 README.md

   📋 Copy# Network Configuration
   
   This repository contains the network configuration for our VXLAN fabric.
   
   ## Structure
   
   ```
   .
   ├── inventory/        # Device inventory
   ├── host_vars/        # Device-specific variables
   ├── group_vars/       # Group variables (Spines, Leafs)
   ├── templates/        # Jinja2 templates
   └── playbooks/        # Ansible Playbooks
   ```
   
   ## Usage
   
   ```bash
   # Validate configuration
   ansible-playbook playbooks/validate.yml
   
   # Deploy configuration (staging only)
   ansible-playbook playbooks/deploy.yml -l staging
   ```
   
   ## Contact
   
   Maintainer: YOUR NAME

2. Commit and push changes (in PowerShell):

   📋 Copygit status
   git add README.md
   git commit -m "docs: README mit Projektstruktur aktualisiert"
   git push origin master

3. Alternative: Commit and push directly in VS Code

   You can also commit changes directly via the VS Code Source Control sidebar without using the terminal:

   1. Click on the Source Control icon on the left (branch symbol, or Ctrl+Shift+G)
   2. You will see the changed files under "Changes"
   3. Click on the + next to the file (or "Stage All Changes") to stage it
   4. Enter a commit message in the text field at the top
   5. Click the "Commit" button (✓ checkmark)
   6. Click on "Sync Changes" or the three dots → Push to push to the server

   

   🔍 Enlarge

4. Verify in GitLab: Open your project in the browser and verify that the README is displayed.

Protect your main branch from direct pushes.

1. Navigate in GitLab:
   • Open your project
   • Go to Settings → Repository
   • Expand Protected branches
2. Protect the branch:
   • Branch: main
   • Allowed to merge: Maintainers
   • Allowed to push and merge: No one
   • Click Protect
3. Test the protection (in PowerShell):

   📋 Copy# Try to push directly to main
   Add-Content -Path README.md -Value "# Test"
   git add .
   git commit -m "test: direkter push"
   git push origin main
   
   # Expected result: ERROR!
   # remote: GitLab: You are not allowed to push code to protected branches

4. Undo the change:

   📋 Copygit reset --hard HEAD~1

5. Disable Protected Branch again:

   So that we can push directly to main again in the following exercises, remove the branch protection:

   • Go to Settings → Repository → Protected branches
   • Click Unprotect next to main
   • Confirm the action

Create a complete Merge Request.

1. Create a feature branch (in PowerShell):

   📋 Copycd netzwerk-config-IHRNAME
   git checkout main
   git pull origin main
   git checkout -b feature/add-vlan-200
   
   # Create directory
   New-Item -ItemType Directory -Force -Path vlans

   Create a new file vlans/vlan200.yaml in VS Code with the following content:

   📄 vlans/vlan200.yaml

   📋 Copy---
   vlan:
     id: 200
     name: Clients
     description: "Client-Netzwerk für Arbeitsplätze"
     ip_range: "10.200.0.0/24"
     gateway: "10.200.0.1"
     dhcp_enabled: true

   Then commit and push:

   📋 Copygit add .
   git commit -m "feat: VLAN 200 für Client-Netzwerk"
   git push -u origin feature/add-vlan-200

2. Create MR in GitLab:
   • Click the link in the push output OR
   • Go to Merge requests → New merge request
   • Source: feature/add-vlan-200
   • Target: main
3. Fill in the MR:
   • Title: "feat: VLAN 200 für Client-Netzwerk hinzufügen"
   • Description: What, why, how to test?
   • Reviewer: Leave the field empty or assign yourself (in practice, you would assign a colleague as reviewer)

Practice the Code Review workflow by reviewing your own Merge Request. In practice, a colleague would perform this review -- here you learn the tools and features.

1. Open your MR:
   • Go to Merge requests
   • Open your MR from Exercise 4
   • Switch to the Changes tab
2. Leave comments:
   • Click on a line to leave a comment
   • Add at least 3 comments with different prefixes:
   • question: Why /24 instead of /23 for the client network?
   • nit: VLAN name could be more descriptive
   • praise: Clean YAML structure! 👍
3. Create a suggestion:
   • Create a new comment on a code line
   • Click on the Suggestion icon (💡)
   • Write a concrete change proposal in the code block
   • E.g. change the VLAN name from "Clients" to "Client-Workstations"
4. Respond to comments and resolve threads:
   • Reply to your own comments (e.g. "Good point, will be adjusted")
   • For the suggestion: Click Apply suggestion
   • Resolve all addressed threads via the Resolve thread button

Complete the review process by approving and merging your own MR.

1. Approve your own MR:
   • Open your MR from Exercise 4
   • Make sure all threads are resolved
   • Click on Approve
   ℹ️Self-Approval in the Workshop

   As a root/admin user, you can approve your own MR. In a production environment, this would be prevented by approval rules -- there, another colleague must approve the MR (four-eyes principle).
2. Merge the MR:
   • Click on Merge
   • Option: Enable Delete source branch
3. Update locally (in PowerShell):

   📋 Copygit checkout main
   git pull origin main
   
   # Verify that the changes are there
   dir vlans/
   Get-Content vlans/vlan200.yaml

4. Verify in GitLab:
   • The MR shows status Merged
   • The feature branch was deleted
   • The file vlans/vlan200.yaml is visible on main

Create an issue and resolve it with a Merge Request.

1. Create an issue:
   • Go to Issues → New issue
   • Title: "Set up VLAN 300 for Guest WiFi"
   • Description:

     📋 Copy## Requirement
     Guest WiFi needs its own VLAN with internet access.
     
     ## Technical Details
     - VLAN ID: 300
     - Name: Guest-WiFi
     - IP Range: 10.30.0.0/24
     - Gateway: 10.30.0.1
     
     ## Acceptance Criteria
     - [ ] VLAN configured
     - [ ] Gateway reachable
     - [ ] Internet access working

   • Add a label: feature
   • Note the issue number (e.g. #1)
2. Feature branch with issue reference (in PowerShell):

   📋 Copygit checkout main
   git pull origin main
   git checkout -b feature/issue-1-vlan-300

   Create a new file vlans/vlan300.yaml in VS Code:

   📄 vlans/vlan300.yaml

   📋 Copy---
   vlan:
     id: 300
     name: Guest-WiFi
     description: "Gäste-WLAN mit Internet-Zugang"
     ip_range: "10.30.0.0/24"
     gateway: "10.30.0.1"
     dhcp_enabled: true
     internet_access: true
     internal_access: false

   Then commit and push:

   📋 Copygit add .
   git commit -m "feat: VLAN 300 für Gäste-WLAN
   
   Closes #1"
   git push -u origin feature/issue-1-vlan-300

3. Create MR:
   • In the description: Closes #1
   • Verify that the issue is shown as linked
4. Merge MR and check issue:
   • After the merge: Open the issue
   • It should be automatically closed!