feat(http): add flux query service client

http/query_handler.go

@@ -8,6 +8,8 @@ import (
 	"io"
 	"net/http"
 
+	"github.com/influxdata/flux"
+	"github.com/influxdata/flux/csv"
 	"github.com/influxdata/platform"
 	pcontext "github.com/influxdata/platform/context"
 	"github.com/influxdata/platform/kit/errors"
@@ -138,8 +140,64 @@ func (s *FluxService) Query(ctx context.Context, w io.Writer, r *query.ProxyRequ
 		return 0, err
 	}
 	defer resp.Body.Close()
+
 	if err := CheckError(resp); err != nil {
 		return 0, err
 	}
 	return io.Copy(w, resp.Body)
 }
+
+var _ query.QueryService = (*FluxQueryService)(nil)
+
+// FluxQueryService implements query.QueryService by making HTTP requests to the /v2/query API endpoint.
+type FluxQueryService struct {
+	URL                string
+	Token              string
+	InsecureSkipVerify bool
+}
+
+// Query runs a flux query against a influx server and decodes the result
+func (s *FluxQueryService) Query(ctx context.Context, req *query.Request) (flux.ResultIterator, error) {
+	u, err := newURL(s.URL, fluxPath)
+	if err != nil {
+		return nil, err
+	}
+
+	preq := &query.ProxyRequest{
+		Request: *req,
+		Dialect: csv.DefaultDialect(),
+	}
+	var body bytes.Buffer
+	if err := json.NewEncoder(&body).Encode(preq); err != nil {
+		return nil, err
+	}
+
+	hreq, err := http.NewRequest("POST", u.String(), &body)
+	if err != nil {
+		return nil, err
+	}
+
+	tok, err := pcontext.GetToken(ctx)
+	if err != nil {
+		tok = s.Token
+	}
+	SetToken(tok, hreq)
+
+	hreq.Header.Set("Content-Type", "application/json")
+	hreq.Header.Set("Accept", "text/csv")
+	hreq = hreq.WithContext(ctx)
+
+	hc := newClient(u.Scheme, s.InsecureSkipVerify)
+	resp, err := hc.Do(hreq)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if err := CheckError(resp); err != nil {
+		return nil, err
+	}
+
+	decoder := csv.NewMultiResultDecoder(csv.ResultDecoderConfig{})
+	return decoder.Decode(resp.Body)
+}