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Fix tests

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Add a whole bunch of comments to document what we are trying to do.
This commit is contained in:
Miek Gieben
2017-08-19 10:45:19 +01:00
parent 118ef3dfa0
commit 4cbf015517
5 changed files with 68 additions and 53 deletions
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47
middleware/kubernetes/parse.go
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@@ -24,15 +24,15 @@ type recordRequest struct {
}
// parseRequest parses the qname to find all the elements we need for querying k8s. Anything
// that is not parsed will have the wildcard "*" value. Potential underscores are stripped
// from _port and _protocol.
// that is not parsed will have the wildcard "*" value (except r.endpoint).
// Potential underscores are stripped from _port and _protocol.
func (k *Kubernetes) parseRequest(state request.Request) (r recordRequest, err error) {
// 3 Possible cases:
// o SRV Request: _port._protocol.service.namespace.pod|svc.zone
// o A Request (endpoint): endpoint.service.namespace.pod|svc.zone
// o A Request (service): service.namespace.pod|svc.zone
// 1. _port._protocol.service.namespace.pod|svc.zone
// 2. (endpoint): endpoint.service.namespace.pod|svc.zone
// 3. (service): service.namespace.pod|svc.zone
//
// Federations are handled in the federation middleware.
// Federations are handled in the federation middleware. And aren't parsed here.
base, _ := dnsutil.TrimZone(state.Name(), state.Zone)
segs := dns.SplitDomainName(base)
@@ -40,8 +40,9 @@ func (k *Kubernetes) parseRequest(state request.Request) (r recordRequest, err e
r.port = "*"
r.protocol = "*"
r.service = "*"
r.endpoint = "" // TODO(miek): dangerous; should just work with "*", but "" is checked in k.get()
r.namespace = "*"
// r.endpoint is the odd one out, we need to know if it has been set or not. If it is
// empty we should skip the endpoint check in k.get(). Hence we cannot set if to "*".
// start at the right and fill out recordRequest with the bits we find, so we look for
// pod|svc.namespace.service and then either
@@ -70,27 +71,31 @@ func (k *Kubernetes) parseRequest(state request.Request) (r recordRequest, err e
return r, nil
}
if segs[last][0] == '_' {
r.protocol = segs[last][1:]
} else {
// Becuase of ambiquity we check the labels left: 1: an endpoint. 2: port and protocol.
// Anything else is a query that is too long to answer and can safely be delegated to return an nxdomain.
switch last {
case 0: // endpoint only
r.endpoint = segs[last]
}
last--
if last < 0 {
return r, nil
}
case 1: // service and port
r.protocol = stripUnderscore(segs[last])
r.port = stripUnderscore(segs[last-1])
if segs[last][0] == '_' {
r.port = segs[last][1:]
}
if last > 0 { // Too long, so NXDOMAIN these.
default: // too long
return r, errInvalidRequest
}
return r, nil
}
// stripUnderscore removes a prefixed underscore from s.
func stripUnderscore(s string) string {
if s[0] != '_' {
return s
}
return s[1:]
}
// String return a string representation of r, it just returns all fields concatenated with dots.
// This is mostly used in tests.
func (r recordRequest) String() string {