Install Atatus Ruby APM agent in Rails server

Supported Versions

4.2 and above.

Installation steps

Add the Atatus agent gem to your Gemfile.

copy
```
gem 'atatus'
```
Install the Atatus Ruby agent.

copy
```
bundle install
```
The Ruby bundle install will automatically require Atatus.
Config File Structure:

The Ruby agent's atatus.yml is a YAML configuration file comprising a common section followed by environment-specific sections like development, testing, and production.

Environment Detection:

The agent selects the config section based on environment variables like RUBY_ENV, RAILS_ENV, or RACK_ENV. If none are set, it defaults to the development environment.

Failure to indent correctly may result in the agent throwing an error during startup, indicating "Unable to parse configuration file".
```
development:
  license_key: 'YOUR_LICENSE_KEY'
  app_name: "rails app (Development)"
production:
  license_key: 'YOUR_LICENSE_KEY'
  app_name: "rails app (Production)"
```
Example:

config/atatus.yml
```
development:
  license_key: 'lic_apm_******'
  app_name: "rails app (Development)"
production:
  license_key: 'lic_apm_******'
  app_name: "rails app (Production)"
```
Restart your Rails ruby server to view your performance data within minutes.