Infura Problems with Required API key

[kclowes]

What was wrong?

If there is no Infura environment variable set, web3 v5 tests can't run because ethpm is loading Infura here: https://github.com/ethpm/py-ethpm/blob/master/ethpm/backends/registry.py#L5

How can it be fixed?

@pipermerriam suggested a few things:
Since we need to get this out before 3/27, we can back out ethpm from v5 for a minute, and then add it back in after we've made "the fix"
"The fix" might look like:

• Passing a web3 instance to ethpm (least user friendly option, but least error prone)
• Check for the environment variable and auto connect to infura if the environment variable is set
• Something else...?

Probably all of these options require some documentation updates

[njgheorghita]

piggy backing off this issue

Removing it from constants and coming up with the mechanism that 1) doesn't require users to use infura since it effectively leaks privacy information and we shouldn't have a hard dependency on a centralized solution but 2) still preserves as much ease of usability as possible.

I recognize moving away from infura probably goes opposite of conversations you and I had about it being a fine solution, but with this stuff moving into production I think it's now time to address that particular piece of debt.

This probably really means leaving the ethpm library such that it require more manual configuration and addressing the usability component in the web3.py codebase.