Add partial support for admin_peers JSON-RPC API

[cburgdorf]

What was wrong?

As part of the things that we want to ship with our first beta, we want to support the admin_peers RPC endpoint.

The response looks something like this in Geth:

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": [
        {
            "enode": "enode://2ea727082ae93766342646f8ac1c98a20a4d14b1c1ca043e1b3c99dfa5a36767692eec2baf7b66474f6bdaca516322fcb45db58173c08a936f6ebab8928d4562@3.1.27.148:30303",
            "id": "e8191234978143d641f1df9898fde0a7a080ef3feb0f6149d857b1fa7d8a4549",
            "name": "Geth/source/linux/go1.10.4",
            "caps": [
                "eth/62",
                "eth/63"
            ],
            "network": {
                "localAddress": "172.17.0.2:56092",
                "remoteAddress": "3.1.27.148:30303",
                "inbound": false,
                "trusted": false,
                "static": false
            },
            "protocols": {
                "eth": {
                    "version": 63,
                    "difficulty": 729514544367193473735,
                    "head": "0x66f682d761aaabe7a98a1bc1b35303ef9c21b1b6c0a35c61965bce13f5499d28"
                }
            }
        },
        {
            "enode": "enode://c25a1d915f9cc87705690bd59af1776cf0ccc3fb7e8dfd31f5f37ef4a8b6a758a743a379bad6f0793c1413b10cdc26aa9aacb5bc1581c4625e22bb414af5840e@139.199.66.86:20182",
            "id": "e81f6a84023ea00c66bfc87857d14080136e91412afe2421816cd4c3be96e686",
            "name": "Geth/qk_client 1.0.1.202 0x4C1a41639D5bf12b8F5D1A83B2aFcbB6100174Eb/v1.9.11-stable-6a62fe39/windows-amd64/go1.13.8",
            "caps": [
                "eth/63",
                "eth/64",
                "eth/65",
                "les/2",
                "les/3"
            ],
            "network": {
                "localAddress": "172.17.0.2:51214",
                "remoteAddress": "139.199.66.86:20182",
                "inbound": false,
                "trusted": false,
                "static": false
            },
            "protocols": {
                "eth": "handshake"
            }
        }
    ]
}

How was it fixed?

Actual Trintiy API response:

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": [
        {
            "enode": "enode://c25a56161448824a805edda3de2ca2de1e5ff498fa0ff6d6bc05939a075805d7217ff791bc003b8fe7cf05d8f1338ac578e1e68dc8e3358f5d27ff78799bcbb8@47.94.236.241:30303",
            "id": "40d4dbe8-675c-48c2-867f-b6a0ea919a94",
            "name": "Geth/v1.9.9-stable-01744997/linux-amd64/go1.13.5",
            "caps": [
                "eth/63",
                "eth/64",
                "shh/6"
            ],
            "network": {
                "localAddress": "0.0.0.0:30303",
                "remoteAddress": "47.94.236.241:30303"
            }
        }
    ]
}

Eagle eyes might spot that this is missing the protocols part which I aim to add in a different PR. The current implementation is based only on the information that we can obtain from the BasePeerPool.

To-Do

• Add tests

• Clean up commit history

• Add entry to the release notes

Cute Animal Picture

[cburgdorf]

@pipermerriam So, our GetConnectedPeersResponse contains SessionAPIs now but all the interesting stuff that geth prints out is sitting on the peer. The obvious answer would be to change to not return a list of SessionAPI but something that includes more information (a subset of the actual peer) but I know you've been really deep into the p2p stack the last months and formed an idea of how these things could work in the future so I'm reaching out to here your thoughts before I just hack myself through until I have the missing data :)

[pipermerriam]

I think it would be very reasonable to have a new object returned that aggregates information about the session like:

class PeerInfo(NamedTuple):
    session: SessionAPI
    capabilities: Capabilities
    ...

[pipermerriam]

Lol, it looks like you implemented pretty much the exact thing I typed up 👍