Merge pull request prometheus#16437 from zenador/unwrap-read-client-error

remote: Allow unwrapping of errors when reading from remote client

Author: krajorama

storage/remote/client.go

@@ -384,7 +384,8 @@ func (c *Client) Read(ctx context.Context, query *prompb.Query, sortSeries bool)
 		_ = httpResp.Body.Close()
 
 		cancel()
-		return nil, fmt.Errorf("remote server %s returned http status %s: %s", c.urlString, httpResp.Status, string(body))
+		err := errors.New(string(body))
+		return nil, fmt.Errorf("remote server %s returned http status %s: %w", c.urlString, httpResp.Status, err)
 	}
 
 	contentType := httpResp.Header.Get("Content-Type")

storage/remote/client_test.go

@@ -225,6 +225,7 @@ func TestReadClient(t *testing.T) {
 		expectedSamples       [][]model.SamplePair
 		expectedErrorContains string
 		sortSeries            bool
+		unwrap                bool
 	}{
 		{
 			name:        "sorted sampled response",
@@ -336,6 +337,14 @@ func TestReadClient(t *testing.T) {
 			timeout:               5 * time.Millisecond,
 			expectedErrorContains: "context deadline exceeded: request timed out after 5ms",
 		},
+		{
+			name: "unwrap error",
+			httpHandler: http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+				http.Error(w, "test error", http.StatusBadRequest)
+			}),
+			expectedErrorContains: "test error\n",
+			unwrap:                true,
+		},
 	}
 
 	for _, test := range tests {
@@ -366,6 +375,10 @@ func TestReadClient(t *testing.T) {
 			ss, err := c.Read(context.Background(), query, test.sortSeries)
 			if test.expectedErrorContains != "" {
 				require.ErrorContains(t, err, test.expectedErrorContains)
+				if test.unwrap {
+					err = errors.Unwrap(err)
+					require.EqualError(t, err, test.expectedErrorContains)
+				}
 				return
 			}