open-consul/agent/dns/dns.go
Blake Covarrubias 441a6c9969
Add DNS recursor strategy option (#10611)
This change adds a new `dns_config.recursor_strategy` option which
controls how Consul queries DNS resolvers listed in the `recursors`
config option. The supported options are `sequential` (default), and
`random`.

Closes #8807

Co-authored-by: Blake Covarrubias <blake@covarrubi.as>
Co-authored-by: Priyanka Sengupta <psengupta@flatiron.com>
2021-07-19 15:22:51 -07:00

35 lines
681 B
Go

package dns
import (
"math/rand"
"regexp"
)
// MaxLabelLength is the maximum length for a name that can be used in DNS.
const MaxLabelLength = 63
// InvalidNameRe is a regex that matches characters which can not be included in
// a DNS name.
var InvalidNameRe = regexp.MustCompile(`[^A-Za-z0-9\\-]+`)
type RecursorStrategy string
const (
RecursorStrategySequential RecursorStrategy = "sequential"
RecursorStrategyRandom RecursorStrategy = "random"
)
func (s RecursorStrategy) Indexes(max int) []int {
switch s {
case RecursorStrategyRandom:
return rand.Perm(max)
default:
idxs := make([]int, max)
for i := range idxs {
idxs[i] = i
}
return idxs
}
}