Running commands on servers
You can use aliases for common commands.
Run command on all servers
$ kamal app exec 'ruby -v'
App Host: 192.168.0.1
ruby 3.1.3p185 (2022-11-24 revision 1a6b16756e) [x86_64-linux]
App Host: 192.168.0.2
ruby 3.1.3p185 (2022-11-24 revision 1a6b16756e) [x86_64-linux]
Run command on primary server
$ kamal app exec --primary 'cat .ruby-version'
App Host: 192.168.0.1
3.1.3
Run Rails command on all servers
$ kamal app exec 'bin/rails about'
App Host: 192.168.0.1
About your application's environment
Rails version 7.1.0.alpha
Ruby version ruby 3.1.3p185 (2022-11-24 revision 1a6b16756e) [x86_64-linux]
RubyGems version 3.3.26
Rack version 2.2.5
Middleware ActionDispatch::HostAuthorization, Rack::Sendfile, ActionDispatch::Static, ActionDispatch::Executor, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, ActionDispatch::RemoteIp, Rails::Rack::Logger, ActionDispatch::ShowExceptions, ActionDispatch::DebugExceptions, ActionDispatch::Callbacks, ActionDispatch::Cookies, ActionDispatch::Session::CookieStore, ActionDispatch::Flash, ActionDispatch::ContentSecurityPolicy::Middleware, ActionDispatch::PermissionsPolicy::Middleware, Rack::Head, Rack::ConditionalGet, Rack::ETag, Rack::TempfileReaper
Application root /rails
Environment production
Database adapter sqlite3
Database schema version 20221231233303
App Host: 192.168.0.2
About your application's environment
Rails version 7.1.0.alpha
Ruby version ruby 3.1.3p185 (2022-11-24 revision 1a6b16756e) [x86_64-linux]
RubyGems version 3.3.26
Rack version 2.2.5
Middleware ActionDispatch::HostAuthorization, Rack::Sendfile, ActionDispatch::Static, ActionDispatch::Executor, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, ActionDispatch::RemoteIp, Rails::Rack::Logger, ActionDispatch::ShowExceptions, ActionDispatch::DebugExceptions, ActionDispatch::Callbacks, ActionDispatch::Cookies, ActionDispatch::Session::CookieStore, ActionDispatch::Flash, ActionDispatch::ContentSecurityPolicy::Middleware, ActionDispatch::PermissionsPolicy::Middleware, Rack::Head, Rack::ConditionalGet, Rack::ETag, Rack::TempfileReaper
Application root /rails
Environment production
Database adapter sqlite3
Database schema version 20221231233303
Run Rails runner on primary server
$ kamal app exec -p 'bin/rails runner "puts Rails.application.config.time_zone"'
UTC
Run interactive commands over SSH
You can run interactive commands, like a Rails console or a bash session, on a server (default is primary, use --hosts to connect to another).
Start a bash session in a new container made from the most recent app image:
kamal app exec -i bash
Start a bash session in the currently running container for the app:
kamal app exec -i --reuse bash
Start a Rails console in a new container made from the most recent app image:
kamal app exec -i 'bin/rails console'