Unable to deploy rails application using capistrano, bundle not found

I am trying to deploy my rails application using capistrano but it is giving me "bundle stdout: /home/deploy/.rvm/scripts/set: line 19: exec: bundle: not found" error. I have installed bundler gem on the server still capistrano unable to find bundle.

Capfile content:

require 'capistrano/setup'
require 'capistrano/deploy'
require 'capistrano/bundler'
require 'capistrano/rvm'
require 'capistrano/rails/assets' # for asset handling add
require 'capistrano/rails/migrations' # for running migrations
require 'capistrano/puma'
require 'capistrano/rake'

install_plugin Capistrano::Puma
# Load custom tasks from `lib/capistrano/tasks` if you have any defined
Dir.glob('lib/capistrano/tasks/*.rake').each { |r| import r }

Deploy.rb content :

lock '3.10.0'

set :application, 'app_name'
set :repo_url, 'my-repo-url' # Edit this to match your repository
set :branch, :branch_name
set :deploy_to, '/home/deploy/app_name'
set :pty, true
set :linked_files, %w{config/database.yml config/application.yml}
set :linked_dirs, %w{bin log tmp/pids tmp/cache tmp/sockets vendor/bundle public/system public/uploads}
set :keep_releases, 3
set :rvm_type, :user
set :rvm_ruby_version, 'ruby-2.3.1' # Edit this if you are using MRI Ruby

set :puma_rackup, -> { File.join(current_path, 'config.ru') }
set :puma_state, "#{shared_path}/tmp/pids/puma.state"
set :puma_pid, "#{shared_path}/tmp/pids/puma.pid"
set :puma_bind, "unix://#{shared_path}/tmp/sockets/puma.sock"    #accept array for multi-bind
set :puma_conf, "#{shared_path}/puma.rb"
set :puma_access_log, "#{shared_path}/log/puma_error.log"
set :puma_error_log, "#{shared_path}/log/puma_access.log"
set :puma_role, :app
set :puma_threads, [0, 16]
set :puma_workers, 0
set :puma_worker_timeout, nil
set :puma_init_active_record, true
set :puma_preload_app, false
set :puma_prune_bundler, true

namespace :deploy do
    desc 'Restart application'
  task :restart do
    on roles(:app), in: :sequence, wait: 5 do
      invoke 'puma:restart'
    end
  end

  after  :finishing,    :compile_assets
  after  :finishing,    :cleanup
  after  :finishing,    :restart
end

Production.rb content :

server 'My-IP', user: 'deploy', roles: %w{web app db}
set :puma_env, fetch(:rack_env, fetch(:rails_env, 'production'))

Solution

When deploying a Rails app using capistrano with rvm, you have to be careful that capistrano will switch the ruby version, and it might not the same ruby version as you see.

You can ssh to the remote server and check yourself

ssh deploy@My-IP
ruby -v        # It's probably not 2.3.1
which bundle
rvm use 2.3.1  # This is the actual version that will be used by capistrano
which bundle

If you cannot see the bundle installed within ruby-2.3.1, you can manually install it by

rvm use 2.3.1
gem install bundler

After that, the capistrano deployment should work as expected.