Run multiple crab processes with a single command

Make sure you have installed crab... duh.

Download the relevant release for your machine from the GitHub releases.

First we need to make sure the file is executable e.g.

chmod +x ~/Downloads/crabs-macos

If you are using MacOS Catalina then you'll have to do a stupid thing before you can start using crabs.

Right click on the file you downloaded. Select "Open". A dialog will appear. Select "Open" again. You can then kill the terminal this opened.

Now just move it to somewhere on your path:

mv ~/Downloads/crabs-macos /usr/local/bin/crabs

Run all processes for a project (including a crab router):

crabs

Exclude process(es):

crabs -x worker -x scheduler

Run specified process(es):

crabs router web watch-js

Note: specifying processes will ignore excluded processes so the following would still run the "web" process:

crabs web -x web

You can even use ! and * wildcards e.g.

The following will start all processes beginning with "watch":

crabs 'watch*'

Either of the following will exclude processes containing "worker":

crabs -x '*worker*'
crabs '!*worker*'

You can add global excludes using the CRABS_EXCLUDE environment variable!

Just stick a comma separated list of the things you'd like to exclude in your bash profile (or wherever you put those things).

The following would exclude all processes containing "worker", "scheduler", or "email":

export CRABS_EXCLUDE='*worker*,*scheduler*,*email*'

Because of the special ! and * characters, you will need escape them if you want to match processes with those in the names (which would be really weird, why would you do that?).

E.g. if you had a process called "w*e*b" and a process called "web", running the following would start both:

crabs 'w*e*b'

You would have to escape the *s with something like:

crabs 'w\*e\*b'

View help and usage info:

crabs --help

Crabs uses the crab PROC_FILE environment variable to look for procfiles. You can read how that works in the crab documentation.

You can use the CRABS_EXCLUDE environment variable to globally exclude processes (comma separated) e.g.

export CRABS_EXCLUDE='*worker*,*scheduler*,*email*'

These can still be overridden by specifying them when running crabs. The following would still start a "worker" process even though "*worker*" is globally excluded:

crabs worker

Ensure you are using NodeJS 12.

If you have NVM installed you can simply run the following inside the project directory (each time you work on the project):

nvm use

If you don't have the correct version install already this may prompt you to run (just once):

nvm install

npm ci

npm run dist

This will output several binaries into ./bin.

This will remove any existing installation, output several binaries into ./bin, and symlink the macos binary:

rm /usr/local/bin/crabs && npm run dist && ln bin/crabs-macos /usr/local/bin/crabs