Router Configuration Template Generator

A powerful web-based tool for generating router and network device configurations using Jinja2-style templates. Create dynamic configuration templates with variables, loops, and conditionals, then generate complete configurations through an intuitive form interface.

🚀 Features

• Jinja2-style Template Engine: Full support for {{variables}}, {% for %} loops, and {% if %} conditionals
• Automatic Form Generation: Dynamically creates input forms based on template variables
• YAML Defaults Section: Define default values in a dedicated section at the top of templates
• Real-time Validation: Warning system for unchanged default values
• Syntax Highlighting: Professional highlighting for router configuration commands
• One-Click Export: Download configurations as .cfg files or copy to clipboard
• Responsive Design: Works seamlessly on desktop, tablet, and mobile devices

📖 How to Use

Basic Usage

1. Enter Your Template: Paste your Jinja2-style template in the input area
2. Auto-Parsing: The template is automatically parsed as you type (no button needed!)
3. Fill in Values: Enter values in the generated form fields
4. Generate Configuration: Click "Generate Configuration" to create the final output
5. Export Results: Use "Copy to Clipboard" or "Download as .cfg" to save your configuration

Template Syntax

Variables

hostname {{hostname}}
interface {{interface_name}}
 ip address {{ip_address}} {{subnet_mask}}

For Loops

{% for vlan in vlans %}
vlan {{vlan.id}}
 name {{vlan.name}}
{% endfor %}

Conditionals

{% if enable_ospf %}
router ospf {{ospf_process_id}}
 router-id {{router_id}}
{% endif %}

YAML Defaults Section

Define default values at the beginning of your template:

{% defaults %}
hostname: router-01
interface_name: GigabitEthernet0/1
description: Primary Uplink Interface
ip_address: 192.168.1.1
subnet_mask: 255.255.255.0
admin_state: enable
{% enddefaults %}

! Your template continues here
interface {{interface_name}}
 description {{description}}
 ip address {{ip_address}} {{subnet_mask}}
! {{admin_state}}

Note: If you don't include a defaults section, the application will automatically create one with all detected variables!

🎯 Example Templates

Basic Interface Configuration

{% defaults %}
hostname: core-router
interface: GigabitEthernet0/1
description: Uplink to Distribution
ip_address: 10.0.0.1
subnet_mask: 255.255.255.252
{% enddefaults %}

hostname {{hostname}}
!
interface {{interface}}
 description {{description}}
 ip address {{ip_address}} {{subnet_mask}}
 no shutdown

VLAN Configuration with Loops

{% defaults %}
vlans: [10, 20, 30, 40]
vlan_names: ['Management', 'Voice', 'Data', 'Guest']
{% enddefaults %}

!
{% for vlan in vlans %}
vlan {{vlan}}
 name {{vlan_names[loop.index0]}}
!
{% endfor %}

⚙️ Technical Details

Architecture

• Frontend: Pure HTML5, CSS3, and vanilla JavaScript (no frameworks)
• Template Engine: Custom-built Jinja2-like parser
• Processing: 100% client-side (no server required)
• Storage: Browser memory only (no data persistence)

File Structure

├── index.html          # Main application interface
├── styles.css          # Responsive styling and UI components
├── template-parser.js  # Template parsing and rendering engine
├── app.js             # Application logic and user interface
├── sample-template.txt # Comprehensive example templates
└── README.md          # This documentation

Browser Compatibility

• Chrome 60+
• Firefox 55+
• Safari 12+
• Edge 79+
• Mobile browsers (iOS Safari, Chrome Mobile)

🔧 Advanced Features

Default Value Validation

The application includes a safety feature that warns you if you're about to generate a configuration with unchanged default values. This prevents accidental use of inappropriate defaults in production environments.

Syntax Highlighting

Generated configurations include color-coded highlighting for:

• Router commands (blue)
• Interface names (green)
• Comments (gray)

Loop Management

Easily add or remove items from loops with intuitive controls. The form dynamically adjusts to handle multiple loop iterations.

🚦 Limitations

• Nested Loops: Basic support (complex nesting may have limited functionality)
• Advanced Conditionals: Simple evaluation (complex expressions may not work)
• Template Validation: Basic error checking
• No Persistence: Templates and data are not saved between sessions

🚀 Getting Started

1. Download or clone the project files
2. Open index.html in any modern web browser
3. Start typing your template or use the provided examples
4. No installation or build process required!

📝 Sample Templates

Check the sample-template.txt file for ready-to-use templates including:

• Basic interface configurations
• VLAN setups with loops
• OSPF routing configurations
• Access control lists (ACLs)
• Complex multi-device scenarios

🤝 Contributing

This is an open-source project. Feel free to:

• Report issues or bugs
• Suggest new features
• Submit pull requests
• Improve documentation

📄 License

MIT License - feel free to use this project for personal or commercial purposes.

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Happy Network Configuring! 🎯

This tool is designed for network engineers, DevOps professionals, and anyone who needs to generate consistent network device configurations quickly and efficiently.