knex-waitfordb

Does what it says on the tin. Reads your knexfile.js, tries to run

SELECT 1 + 1;

on your database, if it fails it waits 1000ms, tries again, and returns when it can run it. You can optionally pass a custom delay as last argv or via the --delay [delay] argument. If your knexfile.js is not located in the current working directory you can use the --knexfile [path/to/your/knexfile.js] argument.

What?

It's for use in your npm scripts. You might have something like this:

"scripts": {
  "migrate": "knex migrate:latest"
}

but you need to make sure the database is up to run this, right? So do:

"scripts": {
  "premigrate": "knex-waitfordb",
  "migrate": "knex migrate:latest"
}

and npm install --save-dev knex-waitfordb. Now npm run migrate waits for your database to be up. No hassle!

You can also use it directly in your code:

const waitForDB = require("@motowhere/knex-waitfordb")
waitForDB().then(() => {
  // Do cool database stuff in here
  knex.migrate.latest()
})

Err...

It's really useful in Docker containers. You'll see.

Okay?

And it's MIT.