enable errcheck linter

The errcheck linter makes sure that errors are always check and not
ignored by accident. It spotted a lot of unchecked errors, mostly in the
tests but also some real problem in the code.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

7 files changed, 43 insertions, 12 deletions

diff --git a/libpod/container_copy_linux.go b/libpod/container_copy_linux.go
index 91e712c74..7566fbb12 100644
--- a/libpod/container_copy_linux.go
+++ b/libpod/container_copy_linux.go
@@ -48,7 +48,11 @@ func (c *Container) copyFromArchive(path string, chown bool, rename map[string]s
 		if err != nil {
 			return nil, err
 		}
-		unmount = func() { c.unmount(false) }
+		unmount = func() {
+			if err := c.unmount(false); err != nil {
+				logrus.Errorf("Failed to unmount container: %v", err)
+			}
+		}
 	}
 
 	if c.state.State == define.ContainerStateRunning {
@@ -117,7 +121,11 @@ func (c *Container) copyToArchive(path string, writer io.Writer) (func() error,
 		if err != nil {
 			return nil, err
 		}
-		unmount = func() { c.unmount(false) }
+		unmount = func() {
+			if err := c.unmount(false); err != nil {
+				logrus.Errorf("Failed to unmount container: %v", err)
+			}
+		}
 	}
 
 	statInfo, resolvedRoot, resolvedPath, err := c.stat(mountPoint, path)
diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go
index 31edff762..3c88cc75f 100644
--- a/libpod/container_internal_linux.go
+++ b/libpod/container_internal_linux.go
@@ -1180,7 +1180,11 @@ func (c *Container) createCheckpointImage(ctx context.Context, options Container
 		return err
 	}
 	// Clean-up buildah working container
-	defer importBuilder.Delete()
+	defer func() {
+		if err := importBuilder.Delete(); err != nil {
+			logrus.Errorf("Image builder delete failed: %v", err)
+		}
+	}()
 
 	if err := c.prepareCheckpointExport(); err != nil {
 		return err
@@ -1201,7 +1205,9 @@ func (c *Container) createCheckpointImage(ctx context.Context, options Container
 
 	// Copy checkpoint from temporary tar file in the image
 	addAndCopyOptions := buildah.AddAndCopyOptions{}
-	importBuilder.Add("", true, addAndCopyOptions, options.TargetFile)
+	if err := importBuilder.Add("", true, addAndCopyOptions, options.TargetFile); err != nil {
+		return err
+	}
 
 	if err := c.addCheckpointImageMetadata(importBuilder); err != nil {
 		return err
@@ -1543,7 +1549,11 @@ func (c *Container) importCheckpointImage(ctx context.Context, imageID string) e
 	}
 
 	mountPoint, err := img.Mount(ctx, nil, "")
-	defer img.Unmount(true)
+	defer func() {
+		if err := c.unmount(true); err != nil {
+			logrus.Errorf("Failed to unmount container: %v", err)
+		}
+	}()
 	if err != nil {
 		return err
 	}
diff --git a/libpod/kube.go b/libpod/kube.go
index 8b75a0c44..5a5fe9d35 100644
--- a/libpod/kube.go
+++ b/libpod/kube.go
@@ -1034,7 +1034,11 @@ func generateKubeSecurityContext(c *Container) (*v1.SecurityContext, error) {
 			if err != nil {
 				return nil, errors.Wrapf(err, "failed to mount %s mountpoint", c.ID())
 			}
-			defer c.unmount(false)
+			defer func() {
+				if err := c.unmount(false); err != nil {
+					logrus.Errorf("Failed to unmount container: %v", err)
+				}
+			}()
 		}
 		logrus.Debugf("Looking in container for user: %s", c.User())
 
diff --git a/libpod/networking_linux.go b/libpod/networking_linux.go
index 2770b040e..0c124cf0b 100644
--- a/libpod/networking_linux.go
+++ b/libpod/networking_linux.go
@@ -488,7 +488,7 @@ func (r *Runtime) GetRootlessNetNs(new bool) (*RootlessNetNS, error) {
 		pid := strconv.Itoa(cmd.Process.Pid)
 		err = ioutil.WriteFile(filepath.Join(rootlessNetNsDir, rootlessNetNsSilrp4netnsPidFile), []byte(pid), 0700)
 		if err != nil {
-			errors.Wrap(err, "unable to write rootless-netns slirp4netns pid file")
+			return nil, errors.Wrap(err, "unable to write rootless-netns slirp4netns pid file")
 		}
 
 		defer func() {
diff --git a/libpod/oci_attach_linux.go b/libpod/oci_attach_linux.go
index b5eabec1f..c6af294d5 100644
--- a/libpod/oci_attach_linux.go
+++ b/libpod/oci_attach_linux.go
@@ -274,11 +274,15 @@ func readStdio(conn *net.UnixConn, streams *define.AttachStreams, receiveStdoutE
 	var err error
 	select {
 	case err = <-receiveStdoutError:
-		conn.CloseWrite()
+		if err := conn.CloseWrite(); err != nil {
+			logrus.Errorf("Failed to close stdin: %v", err)
+		}
 		return err
 	case err = <-stdinDone:
 		if err == define.ErrDetach {
-			conn.CloseWrite()
+			if err := conn.CloseWrite(); err != nil {
+				logrus.Errorf("Failed to close stdin: %v", err)
+			}
 			return err
 		}
 		if err == nil {
diff --git a/libpod/runtime_ctr.go b/libpod/runtime_ctr.go
index fd3ffd199..df7174ac6 100644
--- a/libpod/runtime_ctr.go
+++ b/libpod/runtime_ctr.go
@@ -513,7 +513,9 @@ func (r *Runtime) setupContainer(ctx context.Context, ctr *Container) (_ *Contai
 	case define.NoLogging, define.PassthroughLogging:
 		break
 	case define.JournaldLogging:
-		ctr.initializeJournal(ctx)
+		if err := ctr.initializeJournal(ctx); err != nil {
+			return nil, fmt.Errorf("failed to initialize journal: %w", err)
+		}
 	default:
 		if ctr.config.LogPath == "" {
 			ctr.config.LogPath = filepath.Join(ctr.config.StaticDir, "ctr.log")
diff --git a/libpod/util.go b/libpod/util.go
index 51fe60427..1753b4f34 100644
--- a/libpod/util.go
+++ b/libpod/util.go
@@ -55,8 +55,11 @@ func WaitForFile(path string, chWait chan error, timeout time.Duration) (bool, e
 		if err := watcher.Add(filepath.Dir(path)); err == nil {
 			inotifyEvents = watcher.Events
 		}
-		defer watcher.Close()
-		defer watcher.Remove(filepath.Dir(path))
+		defer func() {
+			if err := watcher.Close(); err != nil {
+				logrus.Errorf("Failed to close fsnotify watcher: %v", err)
+			}
+		}()
 	}
 
 	var timeoutChan <-chan time.Time