go-ethereum/p2p
Lucas 804d45cc2e
p2p: DNS resolution for static nodes (#30822)
Closes #23210 

# Context 
When deploying Geth in Kubernetes with ReplicaSets, we encountered two
DNS-related issues affecting node connectivity. First, during startup,
Geth tries to resolve DNS names for static nodes too early in the config
unmarshaling phase. If peer nodes aren't ready yet (which is common in
Kubernetes rolling deployments), this causes an immediate failure:


```
INFO [11-26|10:03:42.816] Starting Geth on Ethereum mainnet...
INFO [11-26|10:03:42.817] Bumping default cache on mainnet         provided=1024 updated=4096
Fatal: config.toml, line 81: (p2p.Config.StaticNodes) lookup idontexist.geth.node: no such host
``` 

The second issue comes up when pods get rescheduled to different nodes -
their IPs change but peers keep using the initially resolved IP, never
updating the DNS mapping.

This PR adds proper DNS support for enode:// URLs by deferring resolution
to connection time. It also handles DNS failures gracefully instead of failing
fatally during startup, making it work better in container environments where
IPs are dynamic and peers come and go during rollouts.

---------

Co-authored-by: Felix Lange <fjl@twurst.com>
2024-12-13 12:46:12 +01:00
..
discover metrics, cmd/geth: change init-process of metrics (#30814) 2024-12-10 13:27:29 +01:00
dnsdisc p2p/dnsdisc: using clear builtin func (#29418) 2024-04-04 12:19:48 +02:00
enode p2p: DNS resolution for static nodes (#30822) 2024-12-13 12:46:12 +01:00
enr p2p/enode: add quic ENR entry (#30283) 2024-09-13 23:47:18 +02:00
msgrate log: remove lazy, remove unused interfaces, unexport methods (#28622) 2023-12-05 11:54:44 +01:00
nat p2p/nat: return correct port for ExtIP NAT (#30234) 2024-07-27 10:18:05 +02:00
netutil p2p/netutil: unittests for addrutil (#30439) 2024-11-11 11:43:22 +01:00
pipes p2p/simulations: remove packages (#30250) 2024-08-12 10:36:48 +02:00
rlpx p2p/simulations: remove packages (#30250) 2024-08-12 10:36:48 +02:00
tracker metrics, cmd/geth: change init-process of metrics (#30814) 2024-12-10 13:27:29 +01:00
dial.go p2p: DNS resolution for static nodes (#30822) 2024-12-13 12:46:12 +01:00
dial_test.go p2p: DNS resolution for static nodes (#30822) 2024-12-13 12:46:12 +01:00
message.go p2p: use atomic types (#27764) 2023-08-01 23:20:52 +02:00
message_test.go p2p: move rlpx into separate package (#21464) 2020-09-22 10:17:39 +02:00
metrics.go metrics, cmd/geth: change init-process of metrics (#30814) 2024-12-10 13:27:29 +01:00
peer.go p2p: fix DiscReason encoding/decoding (#30855) 2024-12-12 12:33:42 +01:00
peer_error.go p2p: fix DiscReason encoding/decoding (#30855) 2024-12-12 12:33:42 +01:00
peer_test.go p2p: DNS resolution for static nodes (#30822) 2024-12-13 12:46:12 +01:00
protocol.go all: update golang/x/ext and fix slice sorting fallout (#27909) 2023-08-12 00:04:12 +02:00
server.go p2p: use package slices to sort in PeersInfo (#29957) 2024-06-09 22:50:22 +02:00
server_nat.go p2p: fix ip change log parameter (#30158) 2024-07-15 10:15:35 +02:00
server_nat_test.go p2p: fix flaky test TestServerPortMapping (#30241) 2024-07-30 07:31:27 -06:00
server_test.go cmd/bootnode, p2p: support for alternate mapped ports (#26359) 2023-07-14 14:58:27 +02:00
transport.go p2p: fix DiscReason encoding/decoding (#30855) 2024-12-12 12:33:42 +01:00
transport_test.go p2p: fix DiscReason encoding/decoding (#30855) 2024-12-12 12:33:42 +01:00
util.go all: assign zero after resize in implementations of heap.Interface (#26296) 2022-12-05 13:49:54 +01:00
util_test.go p2p: new dial scheduler (#20592) 2020-02-13 11:10:03 +01:00