Yarn: Environment variable for yarn cache directory location

[colinodell]

Do you want to request a feature or report a bug?
Feature

What is the current behavior?
Cache location can only be configured via the cache-folder config option.

What is the expected behavior?
Being able to configure the cache location using an environment variable.

Other prominent package managers offer this functionality:

• Composer: COMPOSER_CACHE_DIR
• npm: NPM_CONFIG_CACHE
• RubyGems: GEM_SPEC_CACHE
• bower: bower_storage__packages (unconfirmed)
• pip: PIP_DOWNLOAD_CACHE (unconfirmed)

This is extremely useful for continuous integration - you may want jobs to use a shared cache, but each individual job may not know (or perhaps shouldn't know) where that global cache exists. Additionally, if that global cache directory changes, it's much easier to update a single environment variable in the CI system than updating the yarn commands in every individual project.

I therefore propose using an envvar like YARN_CONFIG_CACHE_FOLDER. If defined, this would take precedence over the default cache directory. (However, it would not take precedence over any cache-folder option used on the command line.)

[zurawiki]

Sounds like a good first bug @colinodell

Can I take take a look and try to send in a PR?

[colinodell]

Yeah absolutely!

[zurawiki]

This feature already seems to exist. The env variable name is YARN_CACHE_FOLDER

$ YARN_CACHE_FOLDER="foo" ./bin/yarn cache dir
foo/v1

[bestander]

Yes, actually Yarn converts all environment variables into
YarnRegistry.config if they have yarn_ prefix.

That is not a widely known fact, do you want to write start a doc on the website for that, @zurawiki ?

[glensc]

@bestander never link to branches! now, what line you had in mind?

🚧 Never link to branches, share a permalink 🚧

• see https://news.ycombinator.com/item?id=8046710
  and https://help.github.com/articles/getting-permanent-links-to-files/
  and https://docs.gitlab.com/ee/user/shortcuts.html#project-files
• hit y
• and perhaps for https://github.com/josephfrazier/octopermalinker (GitHub)