all processes are killed if one process exits

[jmcantrell]

I first noticed this when implementing a "release" task in my procfile for a heroku app.

https://devcenter.heroku.com/articles/release-phase#specifying-release-phase-tasks

According to that document, the Procfile spec should be ok with having a short-lived process run alongside a long-lived one. I've not used any other implementation of foreman, and I'm not sure which one is being used on heroku.

I can see here that a killall signal is being emitted whenever a child process exits. It seems intentional, but I'm trying to understand why that would be the desired behavior.

https://github.com/strongloop/node-foreman/blob/master/lib/proc.js#L50-L54

My test case is as follows:

In Procfile:

release: node release.js
server: node server.js

In release.js:

console.log("running release task");

In server.js:

const net = require("net");
const server = net.createServer(() => {});
server.listen(0, () => console.log("server listening"));
process.on("SIGINT", () => process.exit());

And see that all processes are killed when running nf start. If the release process is removed, you'll notice that the server is not killed.

[stale]

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[jmcantrell]

I wasn’t able to find anything in the documentation describing this behavior. Is this expected?

[hedinfaok]

@jmcantrell I don't maintain this package, but for anyone else out there that wants to use this package and follow the pattern that Heroku is using, here you go.

Looking at https://devcenter.heroku.com/articles/release-phase#specifying-release-phase-tasks, it looks like Heroku altered the Procfile format to include a specific process that runs only during the release phase on their platform. This breaks the idea behind the Procfile, which includes only long-running processes. If any of those processes exists, all processes exit. Why? So you can fix the reason why the service quit :)

To mimic the Heroku experience, you need to include each process in the Procfile in your command line. Given the following Procfile (which builds off of your example):

release: node release.js
server: node server.js
redis: /usr/bin/env redis-server
mongo: /usr/bin/env mongod

For your example, above, it would look like ./node_modules/.bin/nf start server redis mongo. This command will start your server, redis, and mongo processes and display colorful output in your terminal.

When you want to invoke the release process/command, you would run ./node_modules/.bin/nf run release.

Throw those in your yarn scripts or somewhere convenient.

References:

• https://github.com/ddollar/foreman
• http://blog.daviddollar.org/2011/05/06/introducing-foreman.html
• https://ddollar.github.io/foreman/#PROCFILE
• https://github.com/ddollar/foreman/wiki

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[romgrk-comparative]

ping @slnode @rmg ?