// regionLeaders returns a map of regions to the IP of the member that is the
// leader.
func regionLeaders(client *api.Client, mem []*api.AgentMember) (map[string]string, error) {
// Determine the unique regions.
leaders := make(map[string]string)
regions := make(map[string]struct{})
for _, m := range mem {
regions[m.Tags["region"]] = struct{}{}
}
if len(regions) == 0 {
return leaders, nil
}
status := client.Status()
for reg := range regions {
l, err := status.RegionLeader(reg)
if err != nil {
// This error means that region has no leader.
if strings.Contains(err.Error(), "No cluster leader") {
continue
}
return nil, err
}
leaders[reg] = l
}
return leaders, nil
}
