To integrate analytics into Rails application analytics-ruby gem can be used. By using this gem we can identify users and track their activity.

To install into gemfile:

gem 'analytics-ruby', :require => "segment"

After that initialize the gem with your Segment source’s Write Key and an optional error handler in config/initializers/analytics_ruby.rb

require 'segment/analytics'

Analytics = Segment::Analytics.new({
    write_key: 'PUT_YOUR_WRITE_KEY',
    on_error: Proc.new { |status, msg| print msg }
})

Now identify the user using identify method. It includes a unique User ID and any optional traits about the user.

Analytics.identify(
    {
        user_id: user.id,
        traits: {
            email: user.email,
            first_name: user.first_name,
            last_name: user.last_name
        }
    }
)

To track a user event

Analytics.track(
    {
        user_id: user.id,
        event: 'Logged in'
    }
)