Mirrors/coredns
1
0
Fork 0
mirror of https://github.com/coredns/coredns.git synced 2025-10-31 10:13:14 -04:00
Code Issues Packages Projects Releases Wiki Activity

plugin/etcd: Filter empty host field by qtype (#2499)

Browse Source 
When a query, different from a TXT lookup is performed, all services
with a missing `Host` field should be filtered out, as these otherwize
cause a line in the answer section with a single dot (`.`) as the
result. This behavior manifests for example when a TXT record is present
on a domain, eg. an A or SRV lookup is performed on said domain.

If there are no services containing a `Host` field, a `NODATA` response
should be given. If there are other Services, these alone should be
returned for the query.

Filter any service that has an empty Host field from all lookup types
other than TXT to solve this issue. At the same time the check for empty
`Text` fields in TXT queries are also moved to the same check in the
etcd ServiceBackend.
This commit is contained in:
Carl-Magnus Björkell
2019-01-28 17:38:27 +01:00
committed by Miek Gieben
parent e343556687
commit a84c26d78b
4 changed files with 33 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
plugin/etcd/etcd.go
View File

@@ -78,7 +78,7 @@ func (e *Etcd) Records(state request.Request, exact bool) ([]msg.Service, error)
return nil, err
}
segments := strings.Split(msg.Path(name, e.PathPrefix), "/")
return e.loopNodes(r.Kvs, segments, star)
return e.loopNodes(r.Kvs, segments, star, state.QType())
}
func (e *Etcd) get(path string, recursive bool) (*etcdcv3.GetResponse, error) {
@@ -115,7 +115,7 @@ func (e *Etcd) get(path string, recursive bool) (*etcdcv3.GetResponse, error) {
return r, nil
}
func (e *Etcd) loopNodes(kv []*mvccpb.KeyValue, nameParts []string, star bool) (sx []msg.Service, err error) {
func (e *Etcd) loopNodes(kv []*mvccpb.KeyValue, nameParts []string, star bool, qType uint16) (sx []msg.Service, err error) {
bx := make(map[msg.Service]struct{})
Nodes:
for _, n := range kv {
@@ -149,7 +149,10 @@ Nodes:
if serv.Priority == 0 {
serv.Priority = priority
}
sx = append(sx, *serv)
if shouldInclude(serv, qType) {
sx = append(sx, *serv)
}
}
return sx, nil
}
@@ -173,3 +176,13 @@ func (e *Etcd) TTL(kv *mvccpb.KeyValue, serv *msg.Service) uint32 {
}
return serv.TTL
}
// shouldInclude returns true if the service should be included in a list of records, given the qType. For all the
// currently supported lookup types, the only one to allow for an empty Host field in the service are TXT records.
// Similarly, the TXT record in turn requires the Text field to be set.
func shouldInclude(serv *msg.Service, qType uint16) bool {
if qType == dns.TypeTXT {
return serv.Text != ""
}
return serv.Host != ""
}