Add Dockerfiles and scripts for Heroku-22

[dzuelke]

Almost no changes over heroku-20 right now; only bumped libwebp and sorted out a few package versions or name changes (e.g. mime-support to media-types).

Removed postgresql-server-dev-14; libpq-dev is enough since nobody will be building Postgres extensions.

libheif1 is now an explicitly installed package, with headers.

ImageMagick policy hasn't changed since 20.04.

To discuss:

• Ruby removal?
• python2 removal?
• add libssl1.1 runtime library?

GUS-W-10340283

[edmorley]

Thank you for opening this! :-)

Ruby removal?

Yeah I'd like to remove system Ruby from the stack image, since:

• it's been the cause of confusion and support tickets for users who've intended to use Ruby from the Ruby buildpack, but have had invalid buildpack configs or binstubs (and so have actually inadvertently been using system Ruby, which is often not clear from the resultant error messages)
• aside from Python (which is used by Ubuntu, so unavoidable to include) we don't include any other languages in the base image,
• dropping it reduces image size plus security surface area in terms of things that may cause us to need to do an urgent stack image release,
• worst case we can add it back later if needed.

python2 removal?

Yeah I'm happy to remove Python 2 (or more, not add it back given it's not in there as-is). People who need Python 2 for system Python can use heroku-20 in the meantime.

add libssl1.1 runtime library?

It seems there isn't a libssl1.1-dev package available (like there was libssl1.0-dev for 1.0), so it means the most we can do is provide the libssl1.1 runtime library. As such, unless people are attempting to run assets compiled on an older stack on Heroku-22, the runtime library on it's own won't be any use? As such, perhaps we don't include it for now, unless we hear of a use-case that really does need it?

[dzuelke]

Yup agreed on all points @edmorley. I forgot to mention it'll likely be useless to include libssl1.1 for the reason you mentioned; also note that in bionic, you could not install headers for both versions, since the header file paths are identical and the packages thus conflict.

[edmorley]

This is great thank you!