sidechannel: Check error code when closing Unix socket listener

Check the error code when closing the Unix socket listener and drop the
corresponding exclude from our linting rules.

2 files changed, 13 insertions, 3 deletions

diff --git a/.golangci.yml b/.golangci.yml
index b86dc3e55..36368721c 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -71,7 +71,6 @@ linters-settings:
       - (*google.golang.org/grpc.ServerConn).Close
       - (*io.PipeReader).Close
       - (*io.PipeWriter).Close
-      - (*net.UnixConn).Close
       - (*os.File).Close
       - (io.Closer).Close
       - (io/fs.File).Close
diff --git a/internal/gitaly/hook/sidechannel.go b/internal/gitaly/hook/sidechannel.go
index 62c32a059..14fa5304e 100644
--- a/internal/gitaly/hook/sidechannel.go
+++ b/internal/gitaly/hook/sidechannel.go
@@ -107,7 +107,10 @@ func (wt *SidechannelWaiter) run(callback func(*net.UnixConn) error) {
 		if err != nil {
 			return err
 		}
-		defer c.Close()
+		defer func() {
+			// Error is already checked below.
+			_ = c.Close()
+		}()
 
 		// Eagerly remove the socket directory, in case the process exits before
 		// wt.Close() can run.
@@ -115,7 +118,15 @@ func (wt *SidechannelWaiter) run(callback func(*net.UnixConn) error) {
 			return err
 		}
 
-		return callback(c)
+		if err := callback(c); err != nil {
+			return err
+		}
+
+		if err := c.Close(); err != nil {
+			return err
+		}
+
+		return nil
 	}()
 }