Allow arbitrary command (via child process?)

[Sam Adams]

I currently use wait-on for http but have to write something separate for other cases.

E.g. because mysql listens on it's port even when it's not ready to accept connections, i do something like this:

#!/usr/bin/env bash

set -e
i=0
while ! mysqladmin ping -h"$DB_HOST" --silent; do
	i=$((i+1))
	if [[ "$i" -gt '20' ]]; then
		echo "mysql failed to start"
		exit 1
	fi
	sleep 1
done

npx wait-on http://somehttpcheck 

But if wait-on supported a command resource i could do this:

npx wait-on http://somehttpcheck "command:mysqladmin ping -h$DB_HOST"

I'm not sure command is the right naming but hopefully the intention is clear.

[slava hatnuke]

@sadams I have the same need. By custom command (CLI) the need is quite easily covered.
@jeffbski is it possible to bump the topic up? Or what @sadams or me (@slavahatnuke) could resolve such a case?

I feel like the protocol could be command: it describes the thing.

And for example waiting for not-empty directory #96 could look like

• EMPTY:wait-on command:"find /tmp/to-be-empty -maxdepth 0 -empty | grep tmp/to-be-empty"
• NON-EMPTY:wait-on command:"find /tmp/to-be-empty -maxdepth 0 | grep tmp/to-be-empty"

It covers a few topics at once in the issues

• #96 =mentioned before find + grep
• #95 =find + grep
• #90 =just curl it
• #71 =ps | grep it
• #15 =ps | grep

For Linux family systems the tool is brilliant.

For Windows, it could take more effort to cover all mentioned needs in the issues.

I feel like a lot of people are using wait-on in CI/dev/staging environments that are in node.js naturally Linux-based and this solution has a huge impact.

So, wait-on command:"any-command" looks quite promising and I would like to ask you @jeffbski to help.

[slava hatnuke]

@jeffbski I follow up, about improving the functionality of the wait-on command, could you help with the question or it's needed to be forked?