[Slack] Create subscription checkboxes for new Slack user signups

[leecalcote]

Current Behavior
The http://slack.layer5.io sign up form does not provide users the option to subscribe to the community mailing list (https://layer5.io/subscribe).

Desired Behavior
Offer a checkbox to allow users to subscribe to the community mailing list like the two subscription checkboxes offered on the Linkerd Slack signup:

[chandrashritii]

@leecalcote Could you shed some light on where I could find the source file or how I can edit the slack sign up form?
I made and built the changes locally. I'm attaching a screenshot to show the effect.

[leecalcote]

Oh, perfect. Yes, this change will be done a little differently than almost all others across our projects. This is an instance of slackin and is running in a free dyno on Heroku. It's been too long since this deployment has been touched. Let dig up and get you these details.

[chandrashritii]

@leecalcote
Any idea where I could find details (links, config files etc.) about the dyno used on Heroku?

I looked up slackin and found a slackin-extended version of the original slackin repo, which seems to be a better idea.
Following the Readme instructions should help us set up a new sign up form with the added subscription checkbox and any other updates you would like.
Also, going by the instructions in extras, I would need an admin to generate the legacy token. Can that be done?

[leecalcote]

@chandrashritii great suggestion on use of slackin-extended. Let's do it. Yes, I have a legacy Slack token waiting for you and the Heroku credentials as well. 👍

[chandrashritii]

@leecalcote Slack doesn't support generating new API legacy tokens anymore. It instead only allows the creation of Slack apps (refer ~ Legacy-tokens/Slack). A new Legacy token is a requirement for slackin, which is why deploying through Heroku isn't possible.
This is an official issue listed in the slackin as well as slackin-extended repo.
As an alternative to using slackin, Slack now allows work spaces to generate invite URLs without an expiry date, which notifies the admin every time a user signs up and can be shared to up to 2000 people.

I realize this doesn't solve the original issue of adding a checkbox for the community mailing list but the only way to do that now (that I can think of) is to build a node.js app and deploy independently through Heroku or another platform. Please let me know if you want to try that :)
Also, I tried creating a new workspace "Trials" and generated a sign up form using Slack. I'm attaching a screenshot of the same to give you an idea of the end result

[kushthedude]

A better option, let's fork the slackin repository and make changes according to our need. I went through the code and it's pretty much a traditional spa with gulp.

[leecalcote]

Given today's discussion, let's set aside this request for the time being. Thank you for digging into this, @chandrashritii.