Merge branch 'sh-ignore-not-our-ref-errors' into 'main'

Ignore "not our ref" errors from gitlab-sshd error metrics

See merge request gitlab-org/gitlab-shell!656

internal/sshd/connection.go

@@ -21,7 +21,10 @@ import (
 	"gitlab.com/gitlab-org/labkit/log"
 )
 
-const KeepAliveMsg = "keepalive@openssh.com"
+const (
+	KeepAliveMsg   = "keepalive@openssh.com"
+	NotOurRefError = `exit status 128, stderr: "fatal: git upload-pack: not our ref `
+)
 
 var EOFTimeout = 10 * time.Second
 
@@ -173,6 +176,8 @@ func (c *connection) trackError(ctxlog *logrus.Entry, err error) {
 	grpcCode := grpcstatus.Code(err)
 	if grpcCode == grpccodes.Canceled || grpcCode == grpccodes.Unavailable {
 		return
+	} else if grpcCode == grpccodes.Internal && strings.Contains(err.Error(), NotOurRefError) {
+		return
 	}
 
 	metrics.SliSshdSessionsErrorsTotal.Inc()

internal/sshd/connection_test.go

@@ -221,6 +221,7 @@ func TestSessionsMetrics(t *testing.T) {
 		{"unavailable Gitaly", grpcstatus.Error(grpccodes.Unavailable, "unavailable")},
 		{"api error", &client.ApiError{"api error"}},
 		{"disallowed command", disallowedcommand.Error},
+		{"not our ref", grpcstatus.Error(grpccodes.Internal, `rpc error: code = Internal desc = cmd wait: exit status 128, stderr: "fatal: git upload-pack: not our ref 9106d18f6a1b8022f6517f479696f3e3ea5e68c1"`)},
 	} {
 		t.Run(ignoredError.desc, func(t *testing.T) {
 			conn, chans = setup(1, newChannel)