plugins: set upstream unconditionally (#2956)

`upstream` is not needed as a setting; just set if unconditionally and
remove all documentation and tests for it.

At some point we want remove the hanlding for `upstream` as well and
error out on seeing it.

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

plugin/file/README.md

@@ -28,7 +28,6 @@ If you want to round-robin A and AAAA responses look at the *loadbalance* plugin
 file DBFILE [ZONES... ] {
     transfer to ADDRESS...
     reload DURATION
-    upstream
 }
 ~~~
 
@@ -39,9 +38,6 @@ file DBFILE [ZONES... ] {
 * `reload` interval to perform a reload of the zone if the SOA version changes. Default is one minute.
   Value of `0` means to not scan for changes and reload. For example, `30s` checks the zonefile every 30 seconds
   and reloads the zone when serial changes.
-* `upstream` resolve external names found (think CNAMEs) pointing to external names. This is only
-  really useful when CoreDNS is configured as a proxy; for normal authoritative serving you don't
-  need *or* want to use this. CoreDNS will resolve CNAMEs against itself.
 
 ## Examples
 

plugin/file/setup.go

@@ -113,8 +113,8 @@ func fileParse(c *caddy.Controller) (Zones, error) {
 				reload = d
 
 			case "upstream":
-				// ignore args, will be error later.
-				c.RemainingArgs() // clear buffer
+				// remove soon
+				c.RemainingArgs()
 
 			default:
 				return Zones{}, c.Errf("unknown property '%s'", c.Val())

plugin/file/setup_test.go

@@ -41,13 +41,6 @@ func TestFileParse(t *testing.T) {
 			false,
 			Zones{Names: []string{"10.in-addr.arpa."}},
 		},
-		{
-			`file ` + zoneFileName1 + ` example.net. {
-				upstream a
-			}`,
-			false, // OK for now as we disregard any options for the `upstream`.
-			Zones{Names: []string{"example.net."}},
-		},
 		// errors.
 		{
 			`file ` + zoneFileName1 + ` miek.nl {