Make microservice apps easily.
npm install @nicferrier/crankitcrank is a tool for developing with the cranker HTTP(S) application router.
Install it like:
``shell`
$ npm install -g @nicferrier/crankit
and then you can find out about it like:
`shell`
$ crank help
in addition crank with no arguments will always give you a clue.
cranker is a sort of service discovery tool.
A service is a small node program (or anything really) providing an
HTTP API or UI.
To develop with cranker you want to:
* start a cranker router
* start the services that talk to each other or user-agents through cranker
* tell each service about the cranker endpoint so they can find each other
* connect each service to the cranker
* when any service changes then automatically restart it
And you want to do all this without any hassle.
If you are developing a blog with 3 services:
* blog-service
* user-service
* blog-frontend
to start a cranker dev environment, you might:
`shell
$ cd blog-service
$ crank 8080
$ crank startapp blog server.js
$ crank status
/blog blog-service/server.js running for 10 seconds
$ cd ../user-service
$ crank startapp users server.js
error - what router do you mean? specify a port like
crank startapp
$ crank startapp 8080 users server.js
$ crank status
/blog by ../blog-service/server.js on 6652 for 120 seconds
/users by server.js on 6670 for 2 seconds
`
crank saves a directory called .crankit in the directory in whichcrank
it was started. This directory records all the information about the
router running in the background and when you use a commandcrank
without specifying a router tries to find this file to tell it
what to do.
If you want to start something outside that directory you need
The crank process creates TCP ports for your programs to use andAPP_PORT
communicates them to your program through an environment variable:.
For example, your program, called server.js:
`javascript`
const express=require("express");
const app = express();
const listener = app.listen(process.env["APP_PORT"]);
can be started like this:
`
crank startapp blog server.js
crank starts a cranker connector process for server.js with the path
blog and a free port that it has allocated and passed to yourAPP_PORT
program on the environment variable.
crankit has built in directory serving as a handy extra. Don't
feel you have to use it. Making webservers is a trivial process
normally and can often have value.
But if you're needing to start webservers, perhaps for 2 or 3 static
directories of documentation as you develop then perhaps this is a
good way.
It goes like this:
`
$ crankit 9001 # start on port 9001
$ crankit startdir rustdoc ~/.rustup/toolchain/*/share/doc/html # serve the rust docs
$ curl http://localhost:9001/rustdoc # curl from the cranker
you can startdir as many times as you like, but each one has a
separate port internally, they're all internally cranked webservers.
To work with crank you might want to load the completion file.
crank can help with that by sending the completion bash source code
to the console for you:
If you had checked the repository out and were working without crank
installed, you might:
`
$ source <(node crank complete)
Alternatively, if you have installed it, you could just:
`
$ source <(crank complete)
the shell script will warn you if crank is not a defined variable
name.
A fully automated bash completion system could be achieved by putting
this in your .bashrc.
If you have a .crankit file you can shut down everything and restart with:
`
$ crank restart