Log initial peer connection failures

[teor2345]

Motivation

While testing #1762, I noticed that Zebra appears to hang if peers take a long time to connect.

What is actually happening is that peers time out, but those timeouts aren't logged.

Feb 17 10:44:30.545  INFO {zebrad="d524da7a" net="Main"}: zebrad::commands::start: Starting zebrad
Feb 17 10:44:30.546  INFO {zebrad="d524da7a" net="Main"}: zebrad::commands::start: config=ZebradConfig { consensus: Config { checkpoint_sync: false }, metrics: MetricsSection { endpoint_addr: None }, network: Config { listen_addr: 0.0.0.0:8233, network: Mainnet, initial_mainnet_peers: {"dnsseed.str4d.xyz:8233", "dnsseed.z.cash:8233", "mainnet.seeder.zfnd.org:8233", "mainnet.is.yolo.money:8233"}, initial_testnet_peers: {"testnet.seeder.zfnd.org:18233", "dnsseed.testnet.z.cash:18233", "testnet.is.yolo.money:18233"}, peerset_initial_target_size: 50, new_peer_interval: 60s }, state: Config { cache_dir: "/home/dev/.cache/zebra", ephemeral: false, debug_stop_at_height: None }, tracing: TracingSection { use_color: true, filter: None, endpoint_addr: None, flamegraph: None }, sync: SyncSection { max_concurrent=_block_requests: 50, lookahead_limit: 2000 } }
Feb 17 10:44:30.546  INFO {zebrad="d524da7a" net="Main"}: zebrad::commands::start: initializing node state
Feb 17 10:44:30.546  INFO {zebrad="d524da7a" net="Main"}: zebra_state::config: the open file limit is at or above the specified limit new_limit=1024 current_limit=1024 hard_rlimit=Some(524288)
Feb 17 10:44:30.553  INFO {zebrad="d524da7a" net="Main"}: zebra_state::service::finalized_state: Opened Zebra state cache at /home/dev/.cache/zebra/state/v4/mainnet
Feb 17 10:44:30.554  INFO {zebrad="d524da7a" net="Main"}: zebrad::commands::start: initializing chain verifier
Feb 17 10:44:30.570  INFO {zebrad="d524da7a" net="Main"}:init{config=Config { checkpoint_sync: false } network=Mainnet}: zebra_consensus::chain: initializing chain verifier tip=Some((Height(0), block::Hash("00040fe8ec8471911baa1db1266ea15dd06b4a8a5c453883c000b031973dce08"))) max_checkpoint_height=Height(419581)

Feb 17 10:44:30.570  INFO {zebrad="d524da7a" net="Main"}: zebrad::commands::start: initializing network
Feb 17 10:44:30.570  INFO {zebrad="d524da7a" net="Main"}: zebra_network::peer_set::initialize: Sending initial request for peers
Feb 17 10:44:30.570  INFO {zebrad="d524da7a" net="Main"}:listen{addr=0.0.0.0:8233}: zebra_network::peer_set::initialize: Opened Zcash protocol endpoint at 0.0.0.0:8233
Feb 17 10:44:30.571  INFO {zebrad="d524da7a" net="Main"}:add_initial_peers: zebra_network::peer_set::initialize: Connecting to initial peer set initial_peers={95.217.78.170:8233, 144.217.253.98:8233, 173.249.20.4:8233, 167.172.101.107:8233, 13.209.30.221:8233, 8.131.253.129:8233, [2a01:4f9:c010:a1e9::1]:8233, [2a01:4f8:140:2393::2]:8233, 172.104.180.119:8233, 138.201.252.11:8233, [2a01:4f8:201:8367::2]:8233, 94.23.220.214:8233, 47.254.176.240:8233, 45.79.223.173:8233, 194.135.81.61:8233, 138.201.120.49:8233, 59.110.243.62:8233, 46.4.65.10:8233, 75.152.21.54:8233, 118.24.175.14:8233, 37.59.57.96:8233, 91.206.16.214:8233, [2a01:4f8:120:72a3::2]:8233, 54.38.81.80:8233, [2001:41d0:8:cdd7::]:8233, 136.144.215.219:8233, 172.104.189.59:8233, 107.20.83.62:8233, 34.90.231.182:8233, [2a01:7c8:d002:10f:5054:ff:fe5c:dac7]:8233, [2a01:4f9:4a:1e15::2]:8233, 52.15.111.162:8233, 54.37.81.148:8233, 77.93.223.9:8233, 47.254.179.213:8233, 67.183.29.123:8233, 94.156.174.100:8233, 116.62.229.19:8233, 116.202.132.28:8233, 185.148.146.90:8233, 47.90.248.68:8233, 195.201.110.220:8233, 135.181.20.223:8233, 148.251.22.104:8233, 161.97.68.118:8233, 209.141.47.197:8233, 47.253.0.14:8233, 151.80.96.105:8233, [2a01:4f9:4b:42cb::2]:8233, [2a01:7e01::f03c:92ff:fea1:ec5]:8233, 165.22.76.97:8233, 8.210.14.154:8233, 213.136.78.68:8233, 209.145.48.22:8233, [2001:41d0:203:2f50::]:8233, 172.104.127.76:8233, 198.187.30.208:8233, 8.131.230.189:8233, [2001:41d0:303:d64b::]:8233, 161.53.201.188:8233, 85.15.179.171:8233, 147.135.65.99:8233,3.91.227.122:8233, 3.92.60.219:8233, 139.162.138.168:8233, 95.216.46.146:8233, 135.181.49.198:8233, 39.97.242.143:8233, 47.254.178.251:8233, 3.112.252.179:8233, 120.78.77.73:8233, [2605:6400:20:cd0:e56e:e74:bb7:a80]:8233, 149.56.135.165:8233, [2001:41d0:700:223b::]:8233, [2001:41d0:2:5fd6::1]:8233, 116.202.13.16:8233, 161.35.171.22:8233, [2001:41d0:8:ce33::]:8233, [2a01:4f8:b0:920a::5502]:8233, 116.202.129.35:8233, 93.51.53.177:8233, 8.140.105.213:8233, 195.201.11.54:8233, 47.90.244.88:8233, 35.198.119.137:8233}

Solution

Log initial peer connection failures
And standardise another log message

The logs are a bit verbose, but they only happen at startup, and they're better than just hanging with no output.

Review

This fix should be merged when we get time to review it, because we've actually seen this bug happen in CI.