docs: [#10] update all Ubuntu version references from 22.04 to 24.04

- Update cloud-init configuration to reference Ubuntu 24.04 LTS
- Update documentation across infrastructure and guides
- Update Makefile to reference ubuntu-24.04-base.qcow2 image
- Update terraform.tfvars.example with correct Ubuntu 24.04 image URL
- Replace jammy (22.04) URL with noble (24.04) release URL
- Ensure consistency across all documentation and configuration files

All changes maintain backward compatibility and follow existing patterns.
Linting validation passed for all modified files.

Author: josecelano

Makefile

@@ -182,7 +182,7 @@ clean-and-fix: ## Clean up all VMs and fix libvirt permissions
 	@echo "2. Removing OpenTofu state:"
 	@cd $(TERRAFORM_DIR) && rm -f terraform.tfstate terraform.tfstate.backup .terraform.lock.hcl 2>/dev/null || true
 	@echo "3. Cleaning libvirt images:"
-	@sudo rm -f /var/lib/libvirt/images/torrust-tracker-demo* /var/lib/libvirt/images/ubuntu-22.04-base.qcow2 2>/dev/null || true
+	@sudo rm -f /var/lib/libvirt/images/torrust-tracker-demo* /var/lib/libvirt/images/ubuntu-24.04-base.qcow2 2>/dev/null || true
 	@echo "4. Fixing libvirt setup:"
 	@$(MAKE) fix-libvirt
 	@echo "✓ Clean up complete. You can now run 'make apply' safely."

docs/guides/integration-testing-guide.md

@@ -249,7 +249,7 @@ time make apply
 **Expected During Deployment**:
 
 1. Libvirt permissions check and fixes
-2. Download of Ubuntu 22.04 cloud image (~600MB)
+2. Download of Ubuntu 24.04 cloud image (~600MB)
 3. VM disk creation
 4. Cloud-init ISO creation
 5. VM startup

infrastructure/README.md

@@ -81,7 +81,7 @@ make destroy
 Key features:
 
 - Uses KVM/libvirt provider for local virtualization
-- Downloads Ubuntu 22.04 cloud image automatically
+- Downloads Ubuntu 24.04 cloud image automatically
 - Configures VM with appropriate resources
 - Applies cloud-init configuration during boot
 
@@ -152,7 +152,7 @@ make test-syntax
 
 ### Default Configuration
 
-- **OS**: Ubuntu 22.04 LTS
+- **OS**: Ubuntu 24.04 LTS
 - **RAM**: 2GB
 - **CPU**: 2 cores
 - **Disk**: 20GB

infrastructure/cloud-init/user-data.yaml.tpl

@@ -169,7 +169,7 @@ final_message: |
   Torrust Tracker Demo VM setup completed!
 
   System Information:
-  - OS: Ubuntu 22.04 LTS
+  - OS: Ubuntu 24.04 LTS
   - User: torrust (with sudo privileges and password login)
   - Docker: Installed and configured
   - Firewall: UFW enabled with proper SSH rules

infrastructure/docs/bugs/001-ssh-authentication-failure/SSH_BUG_SUMMARY.md

@@ -171,7 +171,7 @@ Since all individual components work, we need to investigate:
 
 ## Technical Details
 
-- **VM Environment**: libvirt/KVM with Ubuntu 22.04 cloud image
+- **VM Environment**: libvirt/KVM with Ubuntu 24.04 cloud image
 - **SSH Configuration**: Both key and password authentication enabled
 - **Network**: UFW firewall with SSH explicitly allowed
 - **Testing Tools**: ssh, sshpass, nc, virsh net-dhcp-leases

infrastructure/docs/infrastructure-overview.md

@@ -48,7 +48,7 @@ Makefile                             # Build automation and shortcuts
 ### Local VM Testing
 
 - **KVM/libvirt virtualization** for local testing
-- **Ubuntu 22.04 LTS** base image with cloud-init
+- **Ubuntu 24.04 LTS** base image with cloud-init
 - **Automated VM provisioning** with OpenTofu
 - **Reproducible environments** identical to production
 
@@ -107,7 +107,7 @@ make destroy
 
 ### Default Configuration
 
-- **OS**: Ubuntu 22.04 LTS
+- **OS**: Ubuntu 24.04 LTS
 - **RAM**: 2GB (configurable)
 - **CPU**: 2 cores (configurable)
 - **Disk**: 20GB (configurable)

infrastructure/docs/local-testing-setup.md

@@ -153,7 +153,7 @@ tofu apply
 
 The deployment will:
 
-- Download Ubuntu 22.04 cloud image
+- Download Ubuntu 24.04 cloud image
 - Create a VM with specified resources
 - Apply cloud-init configuration
 - Set up basic system requirements
@@ -174,7 +174,7 @@ The deployed VM includes:
 
 ### System Configuration
 
-- Ubuntu 22.04 LTS
+- Ubuntu 24.04 LTS
 - User `torrust` with sudo privileges
 - SSH key authentication
 - Automatic security updates enabled

infrastructure/terraform/terraform.tfvars.example

@@ -12,6 +12,6 @@ vm_disk_size = 20   # GB - Disk size
 # vm_vcpus    = 4     # 4 CPU cores
 # vm_disk_size = 30   # 30GB disk
 
-# Base image (Ubuntu 22.04 LTS)
+# Base image (Ubuntu 24.04 LTS)
 # You can override this to use a different Ubuntu version
-# base_image_url = "https://cloud-images.ubuntu.com/jammy/current/jammy-server-cloudimg-amd64-disk-kvm.img"
+# base_image_url = "https://cloud-images.ubuntu.com/releases/24.04/release/ubuntu-24.04-server-cloudimg-amd64.img"