tree ac04077adea875cf28f8c52f427c72c780b383ae
parent 5f1a7de2dfb5db1884fcb677a0bd38daf6dd3c97
author Jan Schär <jan@monogon.tech> 1726569534 +0200
committer Jan Schär <jan@monogon.tech> 1726761554 +0000

third_party/go: patch etcd to fix panic in IsLocalMemberLearner

After removing etcd membership from a node, etcd panics in
IsLocalMemberLearner. Because we currently run etcd embedded in the core
process, this causes the entire machine to reboot.

The panic happens in the Status RPC handler, which we call to obtain the
current etcd leader. Stack trace:

go.etcd.io/etcd/server/v3/etcdserver/api/membership.(*RaftCluster).IsLocalMemberLearner(0xc000879380)
	external/gazelle~~go_deps~io_etcd_go_etcd_server_v3/etcdserver/api/membership/cluster.go:859 +0x26d
go.etcd.io/etcd/server/v3/etcdserver.(*EtcdServer).IsLearner(0xc001020c18?)
	external/gazelle~~go_deps~io_etcd_go_etcd_server_v3/etcdserver/server.go:2813 +0x1a
go.etcd.io/etcd/server/v3/etcdserver/api/v3rpc.(*maintenanceServer).Status(0xc001020bb0, {0xc001d38638?, 0xc001d38638?}, 0xc001d38690?)
	external/gazelle~~go_deps~io_etcd_go_etcd_server_v3/etcdserver/api/v3rpc/maintenance.go:228 +0x137
go.etcd.io/etcd/server/v3/etcdserver/api/v3rpc.(*authMaintenanceServer).Status(0x4a5c340?, {0x3122cf8?, 0xc0026f2f00?}, 0x2d0ebd8?)
	external/gazelle~~go_deps~io_etcd_go_etcd_server_v3/etcdserver/api/v3rpc/maintenance.go:306 +0x25

A node that is no longer a member is also not a learner anymore, so just
return false instead of panicking.

Change-Id: I6fa3d710836852772d5c2bf05dbd63a3d68b1a8b
Reviewed-on: https://review.monogon.dev/c/monogon/+/3436
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
Tested-by: Jenkins CI