Change tarball metadata file to an erlang term file

[ericmj]

• Support it on the server
• Bump tarball version support on the client (2014-08-12) (Hex v0.4.1) (Elixir v0.15.0)
• Build the new tarballs on the client when publishing (2015-02-11) (Hex v0.7.0)
• Change existing tarballs

[jcspencer]

The main changes we'll need to make to build the new tarballs on the client when publishing are:

1. Add a case here to add either metadata.exs or metadata.config to the blob to create the checksum
2. Line 4 and 26 need to changed to support metadata.config
3. And finally, we need to change Line 19 to build an erlang term file instead of serialized Elixir (this logic has already been completed for hex.config updating)

If this is correct, I'll open a PR. (:+1: or :-1: @ericmj?)

Note: After that, we need to create a job that converts the current tarballs to the new format, and recalculates the checksum both inside the tarball and the registry. I've still got to work out how this will work.

[ericmj]

This is blocking while we wait for people to upgrade their Elixir versions. It is too early to break Hex for all versions pre 0.15.0.

[jcspencer]

Note: The erlang term file config logic will be implemented after #57

[jcspencer]

This makes sense. Would we be able to push this change at the time Elixir 1.0 comes around?

[jaimerson]

I think I may have run into this issue. Apparently cowlib, which is a dependency of phoenix framework, only provides metadata.config. I get a ** (Mix) Missing files metadata.exs in /home/jaimerson/.hex/packages/cowlib-1.0.1.tar when trying to install dependencies via mix deps.get. Please disregard this if this has nothing to do with hex, I'm just getting started with elixir.

[josevalim]

@jaimerson Try running mix local.hex and see if updating your hex version fixes the issue.

[ericmj]

@jaimerson Should be fixed now.

[jaimerson]

Ok, working now, thank you, guys 😉

[jcspencer]

@ericmj Are we now able to convert existing v2 tarballs to the new v3 format, or are we still waiting for more adoption?

[ericmj]

@jcspencer It can be done now, I just need to get some time over to do the actual migration.