Improve API compatibility.

- keep supporting regex for old endpoint.
- use reserved keyword for removed property in grpc

docs/api.md

@@ -28,7 +28,7 @@ The Loki server has the following API endpoints (_Note:_ Authentication is out o
   For doing instant queries at a single point in time, accepts the following parameters in the query-string:
 
   - `query`: a logQL query
-  - `limit`: max number of entries to return (not used for sample expression)
+  - `limit`: max number of entries to return (not used for metric queries)
   - `time`: the evaluation time for the query, as a nanosecond Unix epoch (nanoseconds since 1970). Default is always now.
   - `direction`: `forward` or `backward`, useful when specifying a limit. Default is backward.
 
@@ -107,7 +107,7 @@ The Loki server has the following API endpoints (_Note:_ Authentication is out o
   For doing queries over a range of time, accepts the following parameters in the query-string:
 
   - `query`: a logQL query
-  - `limit`: max number of entries to return (not used for sample expression)
+  - `limit`: max number of entries to return (not used for metric queries)
   - `start`: the start time for the query, as a nanosecond Unix epoch (nanoseconds since 1970). Default is always one hour ago.
   - `end`: the end time for the query, as a nanosecond Unix epoch (nanoseconds since 1970). Default is always now.
   - `step`: query resolution step width in seconds. Default 1 second.
@@ -211,7 +211,8 @@ The Loki server has the following API endpoints (_Note:_ Authentication is out o
   so you need to specify the start and end labels accordingly. Querying a long time into the history will cause additional
   load to the index server and make the query slower.
 
-  > This endpoint doesn't accept [sample query](./usage.md#counting-logs).
+  > This endpoint will be deprecated in the future you should use `api/v1/query_range` instead.
+  > You can only query for logs, it doesn't accept [queries returning metrics](./usage.md#counting-logs).
 
   Responses looks like this:
 

pkg/logproto/logproto.proto

@@ -32,6 +32,7 @@ message QueryRequest {
   google.protobuf.Timestamp start = 3 [(gogoproto.stdtime) = true, (gogoproto.nullable) = false];
   google.protobuf.Timestamp end = 4 [(gogoproto.stdtime) = true, (gogoproto.nullable) = false];
   Direction direction = 5;
+  reserved 6;
 }
 
 enum Direction {
@@ -66,9 +67,10 @@ message Entry {
 
 message TailRequest {
   string query = 1;
-  uint32 delayFor = 2;
-  uint32 limit = 3;
-  google.protobuf.Timestamp start = 4 [(gogoproto.stdtime) = true, (gogoproto.nullable) = false];
+  reserved 2;
+  uint32 delayFor = 3;
+  uint32 limit = 4;
+  google.protobuf.Timestamp start = 5 [(gogoproto.stdtime) = true, (gogoproto.nullable) = false];
 }
 
 message TailResponse {

pkg/logql/ast.go

@@ -148,7 +148,7 @@ func (e *filterExpr) Filter() (Filter, error) {
 		}
 
 	default:
-		return nil, fmt.Errorf("unknow matcher: %v", e.match)
+		return nil, fmt.Errorf("unknown matcher: %v", e.match)
 	}
 	next, ok := e.left.(*filterExpr)
 	if ok {

pkg/loki/modules.go

@@ -143,8 +143,12 @@ func (t *Loki) initQuerier() (err error) {
 		t.httpAuthMiddleware,
 	)
 	t.server.HTTP.Path("/ready").Handler(http.HandlerFunc(t.querier.ReadinessHandler))
+
 	t.server.HTTP.Handle("/api/v1/query_range", httpMiddleware.Wrap(http.HandlerFunc(t.querier.RangeQueryHandler)))
 	t.server.HTTP.Handle("/api/v1/query", httpMiddleware.Wrap(http.HandlerFunc(t.querier.InstantQueryHandler)))
+	t.server.HTTP.Handle("/api/v1/label", httpMiddleware.Wrap(http.HandlerFunc(t.querier.LabelHandler)))
+	t.server.HTTP.Handle("/api/v1/label/{name}/values", httpMiddleware.Wrap(http.HandlerFunc(t.querier.LabelHandler)))
+
 	t.server.HTTP.Handle("/api/prom/query", httpMiddleware.Wrap(http.HandlerFunc(t.querier.LogQueryHandler)))
 	t.server.HTTP.Handle("/api/prom/label", httpMiddleware.Wrap(http.HandlerFunc(t.querier.LabelHandler)))
 	t.server.HTTP.Handle("/api/prom/label/{name}/values", httpMiddleware.Wrap(http.HandlerFunc(t.querier.LabelHandler)))

pkg/querier/http.go

@@ -10,17 +10,16 @@ import (
 	"strings"
 	"time"
 
-	"github.com/prometheus/prometheus/promql"
-	"github.com/weaveworks/common/httpgrpc/server"
-
-	"github.com/weaveworks/common/httpgrpc"
-
 	"github.com/cortexproject/cortex/pkg/util"
 	"github.com/go-kit/kit/log/level"
 	"github.com/gorilla/mux"
 	"github.com/gorilla/websocket"
 	"github.com/grafana/loki/pkg/logproto"
 	"github.com/grafana/loki/pkg/logql"
+	"github.com/prometheus/prometheus/pkg/labels"
+	"github.com/prometheus/prometheus/promql"
+	"github.com/weaveworks/common/httpgrpc"
+	"github.com/weaveworks/common/httpgrpc/server"
 )
 
 const (
@@ -166,6 +165,22 @@ func httpRequestToLookback(httpRequest *http.Request) (limit uint32, start, end
 	return
 }
 
+// parseRegexQuery parses regex and query querystring from httpRequest and returns the combined LogQL query.
+// This is used only to keep regexp query string support until it gets fully deprecated.
+func parseRegexQuery(httpRequest *http.Request) (string, error) {
+	params := httpRequest.URL.Query()
+	query := params.Get("query")
+	regexp := params.Get("regexp")
+	if regexp != "" {
+		expr, err := logql.ParseLogSelector(query)
+		if err != nil {
+			return "", err
+		}
+		query = logql.NewFilterExpr(expr, labels.MatchRegexp, regexp).String()
+	}
+	return query, nil
+}
+
 type QueryResponse struct {
 	ResultType promql.ValueType `json:"resultType"`
 	Result     promql.Value     `json:"result"`
@@ -255,6 +270,12 @@ func (q *Querier) LogQueryHandler(w http.ResponseWriter, r *http.Request) {
 		server.WriteError(w, err)
 		return
 	}
+	request.query, err = parseRegexQuery(r)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
 	query := q.engine.NewRangeQuery(q, request.query, request.start, request.end, request.step, request.direction, request.limit)
 	result, err := query.Exec(ctx)
 	if err != nil {
@@ -326,6 +347,12 @@ func (q *Querier) TailHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	tailRequestPtr.Query, err = parseRegexQuery(r)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
 	if tailRequestPtr.DelayFor > maxDelayForInTailing {
 		server.WriteError(w, fmt.Errorf("delay_for can't be greater than %d", maxDelayForInTailing))
 		level.Error(util.Logger).Log("Error in upgrading websocket", fmt.Sprintf("%v", err))