open-consul/agent/router/serf_flooder.go

89 lines
2.2 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package router
import (
"fmt"
"strings"
"github.com/hashicorp/consul/agent/metadata"
"github.com/hashicorp/go-hclog"
"github.com/hashicorp/serf/serf"
)
// FloodAddrFn gets the address and port to use for a given server when
// flood-joining. This will return false if it doesn't have one.
type FloodAddrFn func(*metadata.Server) (string, error)
// FloodJoins attempts to make sure all Consul servers in the src Serf
// instance are joined in the dst Serf instance. It assumes names in the
// src area are of the form <node> and those in the dst area are of the
// form <node>.<dc> as is done for WAN and general network areas in Consul
// Enterprise.
func FloodJoins(logger hclog.Logger, addrFn FloodAddrFn,
localDatacenter string, srcSerf *serf.Serf, dstSerf *serf.Serf) {
// Names in the dst Serf have the datacenter suffixed.
suffix := fmt.Sprintf(".%s", localDatacenter)
// Index the dst side so we can do one pass through the src side
// with cheap lookups.
index := make(map[string]*metadata.Server)
for _, m := range dstSerf.Members() {
ok, server := metadata.IsConsulServer(m)
if !ok {
continue
}
if server.Datacenter != localDatacenter {
continue
}
srcName := strings.TrimSuffix(server.Name, suffix)
index[srcName] = server
}
// Now run through the src side and look for joins.
for _, m := range srcSerf.Members() {
if m.Status != serf.StatusAlive {
continue
}
ok, server := metadata.IsConsulServer(m)
if !ok {
continue
}
if _, ok := index[server.Name]; ok {
continue
}
addr, err := addrFn(server)
if err != nil {
logger.Debug("Failed to flood-join server", "server",
server.Name, "address", server.Addr.String(),
"error", err,
)
continue
}
dstServerName := fmt.Sprintf("%s.%s", server.Name, server.Datacenter)
// Do the join!
n, err := dstSerf.Join([]string{dstServerName + "/" + addr}, true)
if err != nil {
logger.Debug("Failed to flood-join server at address",
"server", dstServerName,
"address", addr,
"error", err,
)
} else if n > 0 {
logger.Debug("Successfully performed flood-join for server at address",
"server", dstServerName,
"address", addr,
)
}
}
}