Eth1 connections

[michaelneuder]

What type of PR is this?
Feature

What does this PR do? Why is it needed?
This implements an API to get the info about current ETH1 connections. It was a feature request opened in #9972.

Which issues(s) does this PR fix?
Fixes #9972.

Other notes for review

1. I added functions to the ChainInfoFetcher interface rather than creating a new interface in the powchain package.
2. For the beacon-chain/powchain/service_test.go, I was only able to unit test CurrentETH1Endpoint() and ETH1Endpoints(). I couldn't find a test that calls dialETH1Nodes. Since the functions are really quite simple, hopefully living without the coverage is OK. But let me know if there is something I am missing.
3. For beacon-chain/rpc/prysm/v1alpha1/node/service_test.go I needed a mock that implemented the powchain.ChainInfoFetcher interface. I added it to the testutil package in beacon-chain/rpc/testutil/mock_powchain_info_fetcher.go. The mock just returns the fields it was constructed with or with the zero values.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
2 out of 3 committers have signed the CLA.

✅ michaelneuder
✅ rauljordan
❌ Michael Neuder

---

Michael Neuder seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[rauljordan]

Awesome work @michaelneuder this works as expected! I hope you don't mind I pushed a few commits to generate the protos and some Bazel fixes. I have just tested this out locally and it works as expected:

curl http://localhost:3500/eth/v1alpha1/node/eth1/connections
{"currentAddress":"http://localhost:8545","currentConnectionError":"Post \"http://localhost:8545\": dial tcp [::1]:8545: connect: connection refused","addresses":["http://localhost:8545"],"connectionErrors":["Post \"http://localhost:8545\": dial tcp [::1]:8545: connect: connection refused"]}%  

I even found out my eth1 node was down due to your feature, so thanks a lot :)

[rauljordan]

For some reason our CLA assistant wants a second Michael to sign the agreement. Ill see if I can skip that, because it might have been from a commit on another computer you had

[michaelneuder]

cool! thanks for the review!! I am going to try to sort out these failing checks in order to merge.

[rauljordan]

hi @michaelneuder I see some failures in building due to
https://github.com/prysmaticlabs/prysm/runs/4794010970?check_suite_focus=true

Once the PR is green, ill make an exception for the CLA assistant and merge

[michaelneuder]

Ok I made a few more changes in regards to the errors we were looking at. I think I messed up the git state a bit, but it seems like all the changes are here. A few notes:

1. I added GetETH1ConnectionStatus to testing/mock/node_service_mock.go. This fixes one of the interface issues.
2. I added the mock interfaces for the powchain side to beacon-chain/powchain/testing/mock_powchain.go. This fixed the other interface issue, and also allowed me to remove my mock fetcher, because I can just use mockPOW.POWChain struct in my beacon-chain/rpc/prysm/v1alpha1/node/server_test.go.

Hoping this fixes the checks that we were erroring out on.

[rauljordan]

Thank you @michaelneuder this is merged!

[nisdas]

It seems I was too late to review this before it was merged in, but there is a resource leak here with regards to dialing the eth1 json-rpc server.

[nisdas]

The clients should be closed after we dial them otherwise there is a resource leak and the connection is
kept active.

[michaelneuder]

sorry, totally missed this. thanks for addressing!

[nisdas]

Same thing applies here

[prestonvanloon]

@michaelneuder Could you kindly address the feedback from @nisdas?
We'll need to fix those concerns or revert these changes prior to next release.
Thanks!

[michaelneuder]

Sorry missed these comments!