A tool to manage rack apps in development with puma
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Update README to mention support of subdomains
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Puma-dev: A fast, zero-config development server for OS X and Linux

Puma-dev is the emotional successor to pow. It provides a quick and easy way to manage apps in development on OS X and Linux.


  • Easy startup and idle shutdown of rack/rails apps
  • Easy access to the apps using the .test subdomain (configurable)
  • Run multiple custom domains at the same time, e.g. .test * .puma.

Why choose puma-dev?

  • https - it Just Works!
  • Supports Rails 5 actioncable via rack.hijack websockets
  • Supports Mac and Linux
  • The honorary pow is no longer maintained

Install on macOS

  • Via Homebrew is the easiest: brew install puma/puma/puma-dev
  • Or download the latest release from https://github.com/puma/puma-dev/releases
  • If you haven't run puma-dev before, run: sudo puma-dev -setup to configure some DNS settings that have to be done as root
  • Run puma-dev -install to configure puma-dev to run in the background on ports 80 and 443 with the domain .test.
    • If you're currently using pow, puma-dev taking control of .test will break it. If you want to just try out puma-dev and leave pow working, pass -d pdev on -install to use .pdev instead.

NOTE: if you had pow installed before in the system, please make sure to run pow's uninstall script. Read more details in the pow manual.

Install on Linux

Domains (.test or similar)

Install the dev-tld-resolver (https://github.com/puma/dev-tld-resolver) to make domains resolve.

Port 80/443 binding

There are 2 options to allow puma-dev to listen on port 80 and 443.

  1. sudo setcap CAP\_NET\_BIND\_SERVICE=+eip /path/to/puma-dev
  2. Use authbind.

You don't need to bind to port 80/443 to use puma-dev but obviously it makes using the .dev domain much nicer.

There is a shortcut for binding to 80/443 by passing -sysbind which overrides -http-port and -https-port.

Important Note On Ports and Domain Names

  • Default ports are 80 and 443
  • Default domain is .test. Previously it was .dev, but it is owned by Google and since Dec 2017 HSTS only with real websites hosted there.
    • Don't use .dev and .foo, as they are real domains
  • Using pow? To avoid conflicts, use different ports and domain or uninstall pow properly.


Run: puma-dev -h

You have the ability to configure most of the values that you'll use day-to-day.

Setup (OS X only)

Run: sudo puma-dev -setup.

This configures the bits that require root access, which allows your user access to the /etc/resolver directory.

Coming from v0.2

Puma-dev v0.3 and later use launchd to access privileged ports, so if you installed v0.2, you'll need to remove the firewall rules.

Run: sudo puma-dev -cleanup

Background Install/Upgrading for port 80 access (OS X only)

If you want puma-dev to run in the background while you're logged in and on a common port, then you'll need to install it.

NOTE: If you installed puma-dev v0.2, please run sudo puma-dev -cleanup to remove firewall rules that puma-dev no longer uses (and will conflict with puma-dev working)

Run puma-dev -install.

If you wish to have puma-dev use a port other than 80, pass it via the -install-port, for example to use port 81: puma-dev -install -install-port 81.

Running in the foreground

Run: puma-dev

Puma-dev will startup by default using the directory ~/.puma-dev, looking for symlinks to apps just like pow. Drop a symlink to your app in there as: cd ~/.puma-dev; ln -s /path/to/my/app test. You can now access your app as test.test.

Running puma-dev in this way will require you to use the listed http port, which is 9280 by default.

Coming from Pow

By default, puma-dev uses the domain .test to manage your apps. If you want to have puma-dev look for apps in ~/.pow, just run puma-dev -pow.


Puma-dev supports loading environment variables before puma starts. It checks for the following files in this order:

  • ~/.powconfig
  • .env
  • .powrc
  • .powenv

Additionally, puma-dev uses a few environment variables to control how puma is started that you can overwrite in your loaded shell config.

  • CONFIG: A puma configuration file to load, usually something like config/puma-dev.rb. Defaults to no config.
  • THREADS: How many threads puma should use concurrently. Defaults to 5.
  • WORKERS: How many worker processes to start. Defaults to 0, meaning only use threads.


If you would like to have puma-dev stop all the apps (for resource issues or because an app isn't restarting properly), you can send puma-dev the signal USR1. The easiest way to do that is:

puma-dev -stop

Uninstall (OS X only)

Run: puma-dev -uninstall

App usage

Simply symlink your apps directory into ~/.puma-dev! That's it!

Sub Directories

If you have a more complex set of applications you want puma-dev to manage, you can use subdirectories under ~/.puma-dev as well. This works by naming the app with a hyphen (-) where you'd have a slash (/) in the hostname. So for instance if you access cool-frontend.test, puma-dev will look for ~/.puma-dev/cool-frontend and if it finds nothing, try ~/.puma-dev/cool/frontend.

Proxy support

Puma-dev can also proxy requests from a nice dev domain to another app. To do so, just write a file (rather than a symlink'd directory) into ~/.puma-dev with the connection information.

For example, to have port 9292 show up as awesome.test: echo 9292 > ~/.puma-dev/awesome.

Or to proxy to another host: echo > ~/.puma-dev/awesome-elsewhere.


Puma-dev automatically makes the apps available via SSL as well. When you first run puma-dev, it will have likely caused a dialog to appear to put in your password. What happened there was puma-dev generates its own CA certification that is stored in ~/Library/Application Support/io.puma.dev/cert.pem.

That CA cert is used to dynamically create certificates for your apps when access to them is requested. It automatically happens, no configuration necessary. The certs are stored entirely in memory so future restarts of puma-dev simply generate new ones.

When -install is used (and let's be honest, that's how you want to use puma-dev), then it listens on port 443 by default (configurable with -install-https-port) so you can just do https://blah.test to access your app via https.

OS X Logging

When puma-dev is installed as a user agent (the default mode), it will log output from itself and the apps to ~/Library/Logs/puma-dev.log. You can refer to there to find out if apps have started and look for errors.

In the future, puma-dev will provide an integrated console for this log output.


Puma-dev supports websockets natively but you may need to tell your web framework to allow the connections.

In the case of rails, you need to configure rails to allow all websockets or websocket requests from certain domains. The quickest way is to add config.action_cable.disable_request_forgery_protection = true to config/environments/development.rb. This will allow all websocket connections while in development.

Do not use disable_request_forgery_protection in production!

Or you can add something like config.action_cable.allowed_request_origins = /(\.test$)|^localhost$/ to allow anything under .test as well as localhost.


Puma-dev supports xip.io domains. It will detect them and strip them away, so that your test app can be accessed as test.A.B.C.D.xip.io.

Run multiple domains

Puma-dev allows you to run multiple local domains. Handy if you're working with more than one client. Simply set up puma-dev like so: puma-dev -install -d first-domain:second-domain

Static file support

Like pow, puma-dev support serving static files. If an app has a public directory, then any urls that match files within that directory are served. The static files have priority over the app.

Subdomains support

Once a virtual host is installed, it's also automatically accessible from all subdomains of the named host. For example, a myapp virtual host could also be accessed at http://www.myapp.test/ and http://assets.www.myapp.test/. You can override this behavior to, say, point www.myapp.test to a different application: just create another virtual host symlink named www.myapp for the application you want.

Status API

Puma-dev is starting to evolve a status API that can be used to introspect it and the apps. To access it, send a request with the Host: puma-dev and the path /status, for example: curl -H "Host: puma-dev" localhost/status.

The status includes:

  • If it is booting, running, or dead
  • The directory of the app
  • The last 1024 lines the app output


puma-dev link [-n name] [dir]

Creates links to app directories into your puma-dev directory (~/.puma-dev by default).


To build puma-dev, follow these steps:

  • Install golang (http://golang.org)
  • Run go get github.com/puma/puma-dev/...
  • Run $GOPATH/bin/puma-dev to use your new binary

Puma-dev uses gb (http://getgb.io) to manage dependencies, so if you're working on puma-dev and need to introduce a new dependency, run gb vendor fetch <package path> to pull it into vendor/src. Then you can use it from within puma-dev/src