librenms-librenms/doc/Developing/Getting-Started.md

# Get ready to contribute to LibreNMS

This document is intended to help you get your local environment set up to contribute code to the LibreNMS project.

## Setting up a development environment

When starting to develop, it may be tempting to just make changes on your production server, but that will make things harder
for you.  Taking a little time to set up somewhere to work on code changes can really help.

Possible options:
 * A Linux computer, VM, or container
 * Another directory on your LibreNMS server
 * Windows Subsystem for Linux
 
### Set up your development git clone
 1. Follow the [documentation on using git](Using-Git.md)
 2. Install development dependencies `./composer_wrapper.php install`
 3. Set variables in .env, including database settings.  Which could be a local or remote MySQL server including your production DB.
```dotenv
APP_ENV=local
APP_DEBUG=true
...
```
 4. Start a development webserver `./lnms serve`
 5. Access the Web UI at http://localhost:8000

### Automated testing
LibreNMS uses continuous integration to test code changes to help reduce bugs.  This also helps guarantee the changes you 
contribute won't be broken in the future.
You can find out more in our [Validating Code Documentation](Validating-Code.md)

### Polling debug output
You can see detailed info by running your polling code in debug mode. If you are looking at a specific 
```bash
./discovery.php -d -h HOSTNAME
./poller.php -d -h HOSTNAME
```

### Inspecting variables
Sometimes you want to find out what a variable contains (such as the data return from an snmpwalk).
You can dump one or more variables and halt execution with the dd() function.
```php
dd($variable1, $variable2);
```

### Inspecting web pages
Installing the development dependencies and setting APP_DEBUG enables the [Laravel Debugbar](https://github.com/barryvdh/laravel-debugbar)
This will allow you to inspect page generation and errors right in your web browser.

### Better code completion in IDEs and editors
You can generate some files to improve code completion. 
(These file are not updated automatically, so you may need to re-run these command periodically)

```bash
./lnms ide-helper:generate
./lnms ide-helper:models -N
```

### Emulating devices
You can capture and emulate devices using [Snmpsim](https://github.com/etingof/snmpsim).  LibreNMS has a set of scripts to make it easier to work with snmprec files.
[LibreNMS Snmpsim helpers](https://github.com/librenms/librenms-snmpsim)

### Laravel documentation
You can find a lot of how LibreNMS works by following the [Laravel Documentation](https://laravel.com/docs/)