plugin/forward: various cleanup (coredns#1949)

Fix documentation and remove the unused From method.

Signed-off-by: Miek Gieben <miek@miek.nl>

plugin/forward/README.md

@@ -63,8 +63,7 @@ forward FROM TO... {
 * `force_tcp`, use TCP even when the request comes in over UDP.
 * `prefer_udp`, try first using UDP even when the request comes in over TCP. If response is truncated
   (TC flag set in response) then do another attempt over TCP. In case if both `force_tcp` and
-  `prefer_udp`.
-  options specified the `force_tcp` takes precedence.
+  `prefer_udp` options specified the `force_tcp` takes precedence.
 * `max_fails` is the number of subsequent failed health checks that are needed before considering
   an upstream to be down. If 0, the upstream will never be marked as down (nor health checked).
   Default is 2.

plugin/forward/forward.go

@@ -112,7 +112,7 @@ func (f *Forward) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg
 			if err == ErrCachedClosed { // Remote side closed conn, can only happen with TCP.
 				continue
 			}
-			// Retry with TCP if truncated and prefer_udp configured
+			// Retry with TCP if truncated and prefer_udp configured.
 			if err == dns.ErrTruncated && !opts.forceTCP && f.opts.preferUDP {
 				opts.forceTCP = true
 				continue
@@ -166,9 +166,7 @@ func (f *Forward) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg
 }
 
 func (f *Forward) match(state request.Request) bool {
-	from := f.from
-
-	if !plugin.Name(from).Matches(state.Name()) || !f.isAllowedDomain(state.Name()) {
+	if !plugin.Name(f.from).Matches(state.Name()) || !f.isAllowedDomain(state.Name()) {
 		return false
 	}
 
@@ -188,9 +186,6 @@ func (f *Forward) isAllowedDomain(name string) bool {
 	return true
 }
 
-// From returns the base domain to match for the request to be forwarded.
-func (f *Forward) From() string { return f.from }
-
 // ForceTCP returns if TCP is forced to be used even when the request comes in over UDP.
 func (f *Forward) ForceTCP() bool { return f.opts.forceTCP }
 
@@ -201,11 +196,11 @@ func (f *Forward) PreferUDP() bool { return f.opts.preferUDP }
 func (f *Forward) List() []*Proxy { return f.p.List(f.proxies) }
 
 var (
-	// ErrNoHealthy means no healthy proxies left
+	// ErrNoHealthy means no healthy proxies left.
 	ErrNoHealthy = errors.New("no healthy proxies")
-	// ErrNoForward means no forwarder defined
+	// ErrNoForward means no forwarder defined.
 	ErrNoForward = errors.New("no forwarder defined")
-	// ErrCachedClosed means cached connection was closed by peer
+	// ErrCachedClosed means cached connection was closed by peer.
 	ErrCachedClosed = errors.New("cached connection was closed by peer")
 )
 
@@ -218,6 +213,7 @@ const (
 	sequentialPolicy
 )
 
+// options holds various options that can be set.
 type options struct {
 	forceTCP  bool
 	preferUDP bool