Invoker

What is Invoker?

Invoker is a utility belt for managing processes in development environment. Use it for managing multiple processes with ease.

Use it for developing web applications on different local domains without /etc/hosts hacks.

How to use it?

First we need to install invoker gem to get command line utility called invoker, we can do that via:

~> gem install invoker

Currently it only works with Ruby >= 1.9.3.

You need to start by creating a ini file which will define processes you want to manage using invoker. An example ini file is included in the repo.

[rails]
directory = /home/gnufied/god_particle
command = bundle exec rails s -p 5000

[dj]
directory = /home/gnufied/god_particle
command = bundle exec ruby script/delayed_job

[events]
directory = /home/gnufied/god_particle
command = bundle exec ruby script/event_server

After that you can start process manager via:

~> invoker start invoker.ini

Above command will start all your processes in one terminal with their stdout/stderr merged and labelled. You can also start Invoker by daeomonizing it, via:

~> invoker start invoker.ini -d

.dev TLD support for OSX and Linux.

You can access http services managed by invoker via command_label.dev domain locally.

To make it work though, you need to run following command, just once from anywhere:

~> sudo invoker setup # read below if you are migrating from Pow

This feature has been well tested to work on both OSX and Linux.

If you decide to remove Invoker, you can remove things installed by Invoker using command

~> sudo invoker uninstall

Now because invoker is making your app server available on a domain. It requires control over port(or needs to know the port) on which your applications will be listening. This can be simply done by replacing specific port number in ini file with $PORT or by specifying a port key. For example:

[terminal]
directory = /home/gnufied/ayr-terminal
port = 3000
command = node app

[cms]
directory = /home/gnufied/mezzainine
command = python manage.py runserver $PORT --noreload

[typo]
directory = /home/gnufied/typo
command = bundle exec rails s -p $PORT

Now these services can be accessed via http://terminal.dev , http://cms.dev http://typo.dev. You can also access them via wildcard subdomains such as *.*.dev.

You can also access any external http process via .dev DNS by running following command:

~> invoker add_http wordpress 8080

Above command will make wordpress available on wordpress.dev even if wordpress was original not started by Invoker. You can access any randomly started process via Invoker like this.

Https support

Invoker uses a self-signed certificate to make all your web applications available via https as well. You absolutely don't have to do anything. Access your webapps on https://app.dev and enjoy!

Procfile support

Invoker is 100% compatbile with Procfile format used by Heroku. If you have been using a Procfile to bootstrap your development stack, you can keep using it with Invoker.

The only thing to remember is, your Procfile must have $PORT in command - for .dev domain feature to work

rails: cd $HOME/rails_app && bundle exec rails s -p $PORT
cms: cd $HOME/cms && python manage.py runserver $PORT

Process managment

Additionally Invoker allows you to manage individual processes. You can start/stop/restart different processes managed by invoker without affecting others. Following commands work for processes started by Procfile as well.

# Will try to stop running delayed job by sending SIGINT to the process
~> invoker remove dj

# If Process can't be killed by SIGINT send a custom signal
~> invoker remove dj -s 9

# add and start running
~> invoker add dj

# List currently running processes managed by invoker
~> invoker list

# Restart process given by command Label
~> invoker reload dj

# Restart process given by command label using specific signal for killing
~> invoker reload dj -s 9

# tail logs of specified process. This is specially useful if you started
# invoker daemonized or you want to watch logs of just one process discarding
# others.
~> invoker tail dj

You can also enable OSX notifications for crashed processes by installing terminal-notifier gem. It is not a dependency, but can be useful if something crashed and you weren't paying attention.

Migrating from Pow

If you are migrating from Pow then first step before running invoker setup is to uninstall Pow:

curl get.pow.cx/uninstall.sh | sh

After that you should run invoker setup as usual. If for some reason you can't uninstall Pow via above command (in case you installed Pow using homebrew), then you should remove Pow daemon manually.

After running invoker setup you will have to switch off wi-fi and then switch it on for resettng OSX network configuration.

ZSH completion

Invoker comes with a ZSH completion script contrib/completion/invoker-completion.zsh. Drop this somewhere in your $fpath (~/.zsh for example) and rename the file to _invoker.

Credits

Invoker is hugely inspired by pow and Foreman. It stands on the shoulder of awesome work done by folks who created Pow & Foreman. The Codemancers team is immensely grateful to them.