fixes ingester querier not honoring filters (#594)

pkg/ingester/instance.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/cortexproject/cortex/pkg/ingester/client"
 	"github.com/cortexproject/cortex/pkg/ingester/index"
+	cutil "github.com/cortexproject/cortex/pkg/util"
 
 	"github.com/grafana/loki/pkg/helpers"
 	"github.com/grafana/loki/pkg/iter"
@@ -149,18 +150,27 @@ func (i *instance) lookupStreams(req *logproto.QueryRequest, matchers []*labels.
 	i.streamsMtx.RLock()
 	defer i.streamsMtx.RUnlock()
 
-	var err error
+	filters, matchers := cutil.SplitFiltersAndMatchers(matchers)
 	ids := i.index.Lookup(matchers)
-	iterators := make([]iter.EntryIterator, len(ids))
-	for j := range ids {
-		stream, ok := i.streams[ids[j]]
+	iterators := make([]iter.EntryIterator, 0, len(ids))
+
+outer:
+	for _, streamID := range ids {
+		stream, ok := i.streams[streamID]
 		if !ok {
 			return nil, ErrStreamMissing
 		}
-		iterators[j], err = stream.Iterator(req.Start, req.End, req.Direction)
+		lbs := client.FromLabelAdaptersToLabels(stream.labels)
+		for _, filter := range filters {
+			if !filter.Matches(lbs.Get(filter.Name)) {
+				continue outer
+			}
+		}
+		iter, err := stream.Iterator(req.Start, req.End, req.Direction)
 		if err != nil {
 			return nil, err
 		}
+		iterators = append(iterators, iter)
 	}
 	return iterators, nil
 }