Gist for ruby-jmeter that will happily down a production rails app for you. Assumes that the application is using devise. Change thread count, duration and rampup to your needs. This will sign in as two different types of uses as a sample. Modify for your needs.

ruby-jmeter test plan as rake file

desc 'Generate and execute jmeter test plan'
task :generate_jmeter_plan do |t, args|
  require 'ruby-jmeter'
  generate_report
end

def generate_report
  uri = URI('https://yourapp.com')
  domain = uri.host
  test do
    threads count: 1, duration: 60 do # rampup: 30
      cookies policy: 'rfc2109', clear_each_iteration: true

      transaction 'Load Tests User Type 1' do
        user_defined_variables [{name: 'email', value: 'put a login email here'}, {name: 'password', value: 'some password'}]

        visit name: 'Visit Signin', url: '/users/sign_in', domain: domain, protocol: 'https', port: 443 do
          extract name: 'csrf-token', xpath: "//meta[@name='csrf-token']/@content", tolerant: true
          extract name: 'csrf-param', xpath: "//meta[@name='csrf-param']/@content", tolerant: true
          extract name: 'authenticity_token', regex: 'name="authenticity_token" value="(.+?)"'
        end

        http_header_manager name: 'X-CSRF-Token', value: '${csrf-token}'

        submit name: 'Submit signin', url: '/users/sign_in', domain: domain, protocol: 'https', port: 443, fill_in: {
                        'authenticity_token' => '${authenticity_token}',
                        'user[email]' => '${email}',
                        'user[password]' => '${password}',
                        '${csrf-param}' => '${csrf-token}'
                      }

        visit name: 'Some Path 1', url: '/path/organization/active', domain: domain, protocol: 'https', port: 443
        visit name: 'Some Path 2', url: '/path/users', domain: domain, protocol: 'https', port: 443
      end

      transaction 'Load Tests User Type 2' do
        user_defined_variables [{name: 'email', value: 'another user type'}, {name: 'password', value: 'some other password'}]

        visit name: 'Visit Signin', url: '/users/sign_in', domain: domain, protocol: 'https', port: 443 do
          extract name: 'csrf-token', xpath: "//meta[@name='csrf-token']/@content", tolerant: true
          extract name: 'csrf-param', xpath: "//meta[@name='csrf-param']/@content", tolerant: true
          extract name: 'authenticity_token', regex: 'name="authenticity_token" value="(.+?)"'
        end

        http_header_manager name: 'X-CSRF-Token', value: '${csrf-token}'

        submit name: 'Submit signin', url: '/users/sign_in', domain: domain, protocol: 'https', port: 443, fill_in: {
                        'authenticity_token' => '${authenticity_token}',
                        'user[email]' => '${email}',
                        'user[password]' => '${password}',
                        '${csrf-param}' => '${csrf-token}'
                      }

        visit name: 'Dashboard', url: '/my_dashboard', domain: domain, protocol: 'https', port: 443
      end

      view_results_in_table
      view_results_tree
      graph_results
      aggregate_graph
    end
  end.run(
    file: 'jmeter.jmx',
    log: 'jmeter.log',
    jtl: 'results.jtl'
    )
end