Remove all instances of named return "err" from Libpod

This was inspired by https://github.com/cri-o/cri-o/pull/3934 and
much of the logic for it is contained there. However, in brief,
a named return called "err" can cause lots of code confusion and
encourages using the wrong err variable in defer statements,
which can make them work incorrectly. Using a separate name which
is not used elsewhere makes it very clear what the defer should
be doing.

As part of this, remove a large number of named returns that were
not used anywhere. Most of them were once needed, but are no
longer necessary after previous refactors (but were accidentally
retained).

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

13 files changed, 98 insertions, 99 deletions

diff --git a/libpod/container_api.go b/libpod/container_api.go
index c7df9d66c..487f75e67 100644
--- a/libpod/container_api.go
+++ b/libpod/container_api.go
@@ -29,7 +29,7 @@ import (
 // Init requires that all dependency containers be started (e.g. pod infra
 // containers). The `recursive` parameter will, if set to true, start these
 // dependency containers before initializing this container.
-func (c *Container) Init(ctx context.Context, recursive bool) (err error) {
+func (c *Container) Init(ctx context.Context, recursive bool) error {
 	span, _ := opentracing.StartSpanFromContext(ctx, "containerInit")
 	span.SetTag("struct", "container")
 	defer span.Finish()
@@ -85,7 +85,7 @@ func (c *Container) Init(ctx context.Context, recursive bool) (err error) {
 // Start requites that all dependency containers (e.g. pod infra containers) be
 // running before being run. The recursive parameter, if set, will start all
 // dependencies before starting this container.
-func (c *Container) Start(ctx context.Context, recursive bool) (err error) {
+func (c *Container) Start(ctx context.Context, recursive bool) error {
 	span, _ := opentracing.StartSpanFromContext(ctx, "containerStart")
 	span.SetTag("struct", "container")
 	defer span.Finish()
@@ -112,7 +112,7 @@ func (c *Container) Start(ctx context.Context, recursive bool) (err error) {
 // Attach call occurs before Start).
 // In overall functionality, it is identical to the Start call, with the added
 // side effect that an attach session will also be started.
-func (c *Container) StartAndAttach(ctx context.Context, streams *define.AttachStreams, keys string, resize <-chan remotecommand.TerminalSize, recursive bool) (attachResChan <-chan error, err error) {
+func (c *Container) StartAndAttach(ctx context.Context, streams *define.AttachStreams, keys string, resize <-chan remotecommand.TerminalSize, recursive bool) (<-chan error, error) {
 	if !c.batched {
 		c.lock.Lock()
 		defer c.lock.Unlock()
@@ -150,7 +150,7 @@ func (c *Container) StartAndAttach(ctx context.Context, streams *define.AttachSt
 }
 
 // RestartWithTimeout restarts a running container and takes a given timeout in uint
-func (c *Container) RestartWithTimeout(ctx context.Context, timeout uint) (err error) {
+func (c *Container) RestartWithTimeout(ctx context.Context, timeout uint) error {
 	if !c.batched {
 		c.lock.Lock()
 		defer c.lock.Unlock()
@@ -160,7 +160,7 @@ func (c *Container) RestartWithTimeout(ctx context.Context, timeout uint) (err e
 		}
 	}
 
-	if err = c.checkDependenciesAndHandleError(); err != nil {
+	if err := c.checkDependenciesAndHandleError(); err != nil {
 		return err
 	}
 
@@ -760,7 +760,7 @@ func (c *Container) Checkpoint(ctx context.Context, options ContainerCheckpointO
 }
 
 // Restore restores a container
-func (c *Container) Restore(ctx context.Context, options ContainerCheckpointOptions) (err error) {
+func (c *Container) Restore(ctx context.Context, options ContainerCheckpointOptions) error {
 	logrus.Debugf("Trying to restore container %s", c.ID())
 	if !c.batched {
 		c.lock.Lock()
diff --git a/libpod/container_exec.go b/libpod/container_exec.go
index 69da6fcfe..bd04ee9b9 100644
--- a/libpod/container_exec.go
+++ b/libpod/container_exec.go
@@ -779,25 +779,25 @@ func (c *Container) execOCILog(sessionID string) string {
 }
 
 // create a bundle path and associated files for an exec session
-func (c *Container) createExecBundle(sessionID string) (err error) {
+func (c *Container) createExecBundle(sessionID string) (retErr error) {
 	bundlePath := c.execBundlePath(sessionID)
-	if createErr := os.MkdirAll(bundlePath, execDirPermission); createErr != nil {
-		return createErr
+	if err := os.MkdirAll(bundlePath, execDirPermission); err != nil {
+		return err
 	}
 	defer func() {
-		if err != nil {
-			if err2 := os.RemoveAll(bundlePath); err != nil {
-				logrus.Warnf("error removing exec bundle after creation caused another error: %v", err2)
+		if retErr != nil {
+			if err := os.RemoveAll(bundlePath); err != nil {
+				logrus.Warnf("error removing exec bundle after creation caused another error: %v", err)
 			}
 		}
 	}()
-	if err2 := os.MkdirAll(c.execExitFileDir(sessionID), execDirPermission); err2 != nil {
+	if err := os.MkdirAll(c.execExitFileDir(sessionID), execDirPermission); err != nil {
 		// The directory is allowed to exist
-		if !os.IsExist(err2) {
-			err = errors.Wrapf(err2, "error creating OCI runtime exit file path %s", c.execExitFileDir(sessionID))
+		if !os.IsExist(err) {
+			return errors.Wrapf(err, "error creating OCI runtime exit file path %s", c.execExitFileDir(sessionID))
 		}
 	}
-	return
+	return nil
 }
 
 // readExecExitCode reads the exit file for an exec session and returns
diff --git a/libpod/container_internal.go b/libpod/container_internal.go
index 12132cf41..e98e20b9b 100644
--- a/libpod/container_internal.go
+++ b/libpod/container_internal.go
@@ -210,7 +210,7 @@ func (c *Container) handleExitFile(exitFile string, fi os.FileInfo) error {
 // Handle container restart policy.
 // This is called when a container has exited, and was not explicitly stopped by
 // an API call to stop the container or pod it is in.
-func (c *Container) handleRestartPolicy(ctx context.Context) (restarted bool, err error) {
+func (c *Container) handleRestartPolicy(ctx context.Context) (_ bool, retErr error) {
 	// If we did not get a restart policy match, exit immediately.
 	// Do the same if we're not a policy that restarts.
 	if !c.state.RestartPolicyMatch ||
@@ -241,7 +241,7 @@ func (c *Container) handleRestartPolicy(ctx context.Context) (restarted bool, er
 	logrus.Debugf("Restarting container %s due to restart policy %s", c.ID(), c.config.RestartPolicy)
 
 	// Need to check if dependencies are alive.
-	if err = c.checkDependenciesAndHandleError(); err != nil {
+	if err := c.checkDependenciesAndHandleError(); err != nil {
 		return false, err
 	}
 
@@ -263,9 +263,9 @@ func (c *Container) handleRestartPolicy(ctx context.Context) (restarted bool, er
 	}
 
 	defer func() {
-		if err != nil {
-			if err2 := c.cleanup(ctx); err2 != nil {
-				logrus.Errorf("error cleaning up container %s: %v", c.ID(), err2)
+		if retErr != nil {
+			if err := c.cleanup(ctx); err != nil {
+				logrus.Errorf("error cleaning up container %s: %v", c.ID(), err)
 			}
 		}
 	}()
@@ -768,7 +768,7 @@ func (c *Container) save() error {
 // Checks the container is in the right state, then initializes the container in preparation to start the container.
 // If recursive is true, each of the containers dependencies will be started.
 // Otherwise, this function will return with error if there are dependencies of this container that aren't running.
-func (c *Container) prepareToStart(ctx context.Context, recursive bool) (err error) {
+func (c *Container) prepareToStart(ctx context.Context, recursive bool) (retErr error) {
 	// Container must be created or stopped to be started
 	if !c.ensureState(define.ContainerStateConfigured, define.ContainerStateCreated, define.ContainerStateStopped, define.ContainerStateExited) {
 		return errors.Wrapf(define.ErrCtrStateInvalid, "container %s must be in Created or Stopped state to be started", c.ID())
@@ -785,9 +785,9 @@ func (c *Container) prepareToStart(ctx context.Context, recursive bool) (err err
 	}
 
 	defer func() {
-		if err != nil {
-			if err2 := c.cleanup(ctx); err2 != nil {
-				logrus.Errorf("error cleaning up container %s: %v", c.ID(), err2)
+		if retErr != nil {
+			if err := c.cleanup(ctx); err != nil {
+				logrus.Errorf("error cleaning up container %s: %v", c.ID(), err)
 			}
 		}
 	}()
@@ -1133,7 +1133,7 @@ func (c *Container) reinit(ctx context.Context, retainRetries bool) error {
 // Initialize (if necessary) and start a container
 // Performs all necessary steps to start a container that is not running
 // Does not lock or check validity
-func (c *Container) initAndStart(ctx context.Context) (err error) {
+func (c *Container) initAndStart(ctx context.Context) (retErr error) {
 	// If we are ContainerStateUnknown, throw an error
 	if c.state.State == define.ContainerStateUnknown {
 		return errors.Wrapf(define.ErrCtrStateInvalid, "container %s is in an unknown state", c.ID())
@@ -1151,9 +1151,9 @@ func (c *Container) initAndStart(ctx context.Context) (err error) {
 	}
 
 	defer func() {
-		if err != nil {
-			if err2 := c.cleanup(ctx); err2 != nil {
-				logrus.Errorf("error cleaning up container %s: %v", c.ID(), err2)
+		if retErr != nil {
+			if err := c.cleanup(ctx); err != nil {
+				logrus.Errorf("error cleaning up container %s: %v", c.ID(), err)
 			}
 		}
 	}()
@@ -1335,7 +1335,7 @@ func (c *Container) unpause() error {
 }
 
 // Internal, non-locking function to restart a container
-func (c *Container) restartWithTimeout(ctx context.Context, timeout uint) (err error) {
+func (c *Container) restartWithTimeout(ctx context.Context, timeout uint) (retErr error) {
 	if !c.ensureState(define.ContainerStateConfigured, define.ContainerStateCreated, define.ContainerStateRunning, define.ContainerStateStopped, define.ContainerStateExited) {
 		return errors.Wrapf(define.ErrCtrStateInvalid, "unable to restart a container in a paused or unknown state")
 	}
@@ -1372,9 +1372,9 @@ func (c *Container) restartWithTimeout(ctx context.Context, timeout uint) (err e
 		}
 	}
 	defer func() {
-		if err != nil {
-			if err2 := c.cleanup(ctx); err2 != nil {
-				logrus.Errorf("error cleaning up container %s: %v", c.ID(), err2)
+		if retErr != nil {
+			if err := c.cleanup(ctx); err != nil {
+				logrus.Errorf("error cleaning up container %s: %v", c.ID(), err)
 			}
 		}
 	}()
@@ -1696,7 +1696,7 @@ func (c *Container) cleanup(ctx context.Context) error {
 
 // delete deletes the container and runs any configured poststop
 // hooks.
-func (c *Container) delete(ctx context.Context) (err error) {
+func (c *Container) delete(ctx context.Context) error {
 	span, _ := opentracing.StartSpanFromContext(ctx, "delete")
 	span.SetTag("struct", "container")
 	defer span.Finish()
@@ -1715,7 +1715,7 @@ func (c *Container) delete(ctx context.Context) (err error) {
 // postDeleteHooks runs the poststop hooks (if any) as specified by
 // the OCI Runtime Specification (which requires them to run
 // post-delete, despite the stage name).
-func (c *Container) postDeleteHooks(ctx context.Context) (err error) {
+func (c *Container) postDeleteHooks(ctx context.Context) error {
 	span, _ := opentracing.StartSpanFromContext(ctx, "postDeleteHooks")
 	span.SetTag("struct", "container")
 	defer span.Finish()
@@ -1838,7 +1838,7 @@ func (c *Container) saveSpec(spec *spec.Spec) error {
 }
 
 // Warning: precreate hooks may alter 'config' in place.
-func (c *Container) setupOCIHooks(ctx context.Context, config *spec.Spec) (extensionStageHooks map[string][]spec.Hook, err error) {
+func (c *Container) setupOCIHooks(ctx context.Context, config *spec.Spec) (map[string][]spec.Hook, error) {
 	allHooks := make(map[string][]spec.Hook)
 	if c.runtime.config.Engine.HooksDir == nil {
 		if rootless.IsRootless() {
@@ -1952,7 +1952,7 @@ func (c *Container) checkReadyForRemoval() error {
 
 // writeJSONFile marshalls and writes the given data to a JSON file
 // in the bundle path
-func (c *Container) writeJSONFile(v interface{}, file string) (err error) {
+func (c *Container) writeJSONFile(v interface{}, file string) error {
 	fileJSON, err := json.MarshalIndent(v, "", "  ")
 	if err != nil {
 		return errors.Wrapf(err, "error writing JSON to %s for container %s", file, c.ID())
@@ -1967,7 +1967,7 @@ func (c *Container) writeJSONFile(v interface{}, file string) (err error) {
 
 // prepareCheckpointExport writes the config and spec to
 // JSON files for later export
-func (c *Container) prepareCheckpointExport() (err error) {
+func (c *Container) prepareCheckpointExport() error {
 	// save live config
 	if err := c.writeJSONFile(c.Config(), "config.dump"); err != nil {
 		return err
diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go
index a3a57ae0f..b2711745e 100644
--- a/libpod/container_internal_linux.go
+++ b/libpod/container_internal_linux.go
@@ -612,7 +612,7 @@ func (c *Container) addNamespaceContainer(g *generate.Generator, ns LinuxNS, ctr
 	return nil
 }
 
-func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) (err error) {
+func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) error {
 	if (len(c.config.NamedVolumes) > 0) || (len(c.Dependencies()) > 0) {
 		return errors.Errorf("Cannot export checkpoints of containers with named volumes or dependencies")
 	}
@@ -723,7 +723,7 @@ func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) (err error)
 	return nil
 }
 
-func (c *Container) checkpointRestoreSupported() (err error) {
+func (c *Container) checkpointRestoreSupported() error {
 	if !criu.CheckForCriu() {
 		return errors.Errorf("Checkpoint/Restore requires at least CRIU %d", criu.MinCriuVersion)
 	}
@@ -733,7 +733,7 @@ func (c *Container) checkpointRestoreSupported() (err error) {
 	return nil
 }
 
-func (c *Container) checkpointRestoreLabelLog(fileName string) (err error) {
+func (c *Container) checkpointRestoreLabelLog(fileName string) error {
 	// Create the CRIU log file and label it
 	dumpLog := filepath.Join(c.bundlePath(), fileName)
 
@@ -750,7 +750,7 @@ func (c *Container) checkpointRestoreLabelLog(fileName string) (err error) {
 	return nil
 }
 
-func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointOptions) (err error) {
+func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointOptions) error {
 	if err := c.checkpointRestoreSupported(); err != nil {
 		return err
 	}
@@ -820,7 +820,7 @@ func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointO
 	return c.save()
 }
 
-func (c *Container) importCheckpoint(input string) (err error) {
+func (c *Container) importCheckpoint(input string) error {
 	archiveFile, err := os.Open(input)
 	if err != nil {
 		return errors.Wrapf(err, "Failed to open checkpoint archive %s for import", input)
@@ -849,8 +849,7 @@ func (c *Container) importCheckpoint(input string) (err error) {
 	return nil
 }
 
-func (c *Container) restore(ctx context.Context, options ContainerCheckpointOptions) (err error) {
-
+func (c *Container) restore(ctx context.Context, options ContainerCheckpointOptions) (retErr error) {
 	if err := c.checkpointRestoreSupported(); err != nil {
 		return err
 	}
@@ -860,7 +859,7 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti
 	}
 
 	if options.TargetFile != "" {
-		if err = c.importCheckpoint(options.TargetFile); err != nil {
+		if err := c.importCheckpoint(options.TargetFile); err != nil {
 			return err
 		}
 	}
@@ -946,9 +945,9 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti
 	}
 
 	defer func() {
-		if err != nil {
-			if err2 := c.cleanup(ctx); err2 != nil {
-				logrus.Errorf("error cleaning up container %s: %v", c.ID(), err2)
+		if retErr != nil {
+			if err := c.cleanup(ctx); err != nil {
+				logrus.Errorf("error cleaning up container %s: %v", c.ID(), err)
 			}
 		}
 	}()
diff --git a/libpod/container_internal_unsupported.go b/libpod/container_internal_unsupported.go
index a42c1d735..e6d94104c 100644
--- a/libpod/container_internal_unsupported.go
+++ b/libpod/container_internal_unsupported.go
@@ -18,7 +18,7 @@ func (c *Container) unmountSHM(mount string) error {
 	return define.ErrNotImplemented
 }
 
-func (c *Container) prepare() (err error) {
+func (c *Container) prepare() error {
 	return define.ErrNotImplemented
 }
 
diff --git a/libpod/events/events_linux.go b/libpod/events/events_linux.go
index ffb100be8..482d7d6dd 100644
--- a/libpod/events/events_linux.go
+++ b/libpod/events/events_linux.go
@@ -8,20 +8,20 @@ import (
 )
 
 // NewEventer creates an eventer based on the eventer type
-func NewEventer(options EventerOptions) (eventer Eventer, err error) {
+func NewEventer(options EventerOptions) (Eventer, error) {
 	logrus.Debugf("Initializing event backend %s", options.EventerType)
 	switch strings.ToUpper(options.EventerType) {
 	case strings.ToUpper(Journald.String()):
-		eventer, err = newEventJournalD(options)
+		eventer, err := newEventJournalD(options)
 		if err != nil {
 			return nil, errors.Wrapf(err, "eventer creation")
 		}
+		return eventer, nil
 	case strings.ToUpper(LogFile.String()):
-		eventer = EventLogFile{options}
+		return EventLogFile{options}, nil
 	case strings.ToUpper(Null.String()):
-		eventer = NewNullEventer()
+		return NewNullEventer(), nil
 	default:
 		return nil, errors.Errorf("unknown event logger type: %s", strings.ToUpper(options.EventerType))
 	}
-	return eventer, nil
 }
diff --git a/libpod/networking_linux.go b/libpod/networking_linux.go
index 7985e17e1..5a8faa7a4 100644
--- a/libpod/networking_linux.go
+++ b/libpod/networking_linux.go
@@ -141,18 +141,18 @@ func (r *Runtime) configureNetNS(ctr *Container, ctrNS ns.NetNS) ([]*cnitypes.Re
 }
 
 // Create and configure a new network namespace for a container
-func (r *Runtime) createNetNS(ctr *Container) (n ns.NetNS, q []*cnitypes.Result, err error) {
+func (r *Runtime) createNetNS(ctr *Container) (n ns.NetNS, q []*cnitypes.Result, retErr error) {
 	ctrNS, err := netns.NewNS()
 	if err != nil {
 		return nil, nil, errors.Wrapf(err, "error creating network namespace for container %s", ctr.ID())
 	}
 	defer func() {
-		if err != nil {
-			if err2 := netns.UnmountNS(ctrNS); err2 != nil {
-				logrus.Errorf("Error unmounting partially created network namespace for container %s: %v", ctr.ID(), err2)
+		if retErr != nil {
+			if err := netns.UnmountNS(ctrNS); err != nil {
+				logrus.Errorf("Error unmounting partially created network namespace for container %s: %v", ctr.ID(), err)
 			}
-			if err2 := ctrNS.Close(); err2 != nil {
-				logrus.Errorf("Error closing partially created network namespace for container %s: %v", ctr.ID(), err2)
+			if err := ctrNS.Close(); err != nil {
+				logrus.Errorf("Error closing partially created network namespace for container %s: %v", ctr.ID(), err)
 			}
 		}
 	}()
@@ -188,7 +188,7 @@ func checkSlirpFlags(path string) (*slirpFeatures, error) {
 }
 
 // Configure the network namespace for a rootless container
-func (r *Runtime) setupRootlessNetNS(ctr *Container) (err error) {
+func (r *Runtime) setupRootlessNetNS(ctr *Container) error {
 	path := r.config.Engine.NetworkCmdPath
 
 	if path == "" {
@@ -342,7 +342,7 @@ func waitForSync(syncR *os.File, cmd *exec.Cmd, logFile io.ReadSeeker, timeout t
 	return nil
 }
 
-func (r *Runtime) setupRootlessPortMapping(ctr *Container, netnsPath string) (err error) {
+func (r *Runtime) setupRootlessPortMapping(ctr *Container, netnsPath string) error {
 	syncR, syncW, err := os.Pipe()
 	if err != nil {
 		return errors.Wrapf(err, "failed to open pipe")
@@ -420,7 +420,7 @@ func (r *Runtime) setupRootlessPortMapping(ctr *Container, netnsPath string) (er
 }
 
 // Configure the network namespace using the container process
-func (r *Runtime) setupNetNS(ctr *Container) (err error) {
+func (r *Runtime) setupNetNS(ctr *Container) error {
 	nsProcess := fmt.Sprintf("/proc/%d/ns/net", ctr.state.PID)
 
 	b := make([]byte, 16)
diff --git a/libpod/networking_unsupported.go b/libpod/networking_unsupported.go
index d5189709c..69f470ff7 100644
--- a/libpod/networking_unsupported.go
+++ b/libpod/networking_unsupported.go
@@ -4,11 +4,11 @@ package libpod
 
 import "github.com/containers/libpod/v2/libpod/define"
 
-func (r *Runtime) setupRootlessNetNS(ctr *Container) (err error) {
+func (r *Runtime) setupRootlessNetNS(ctr *Container) error {
 	return define.ErrNotImplemented
 }
 
-func (r *Runtime) setupNetNS(ctr *Container) (err error) {
+func (r *Runtime) setupNetNS(ctr *Container) error {
 	return define.ErrNotImplemented
 }
 
@@ -16,7 +16,7 @@ func (r *Runtime) teardownNetNS(ctr *Container) error {
 	return define.ErrNotImplemented
 }
 
-func (r *Runtime) createNetNS(ctr *Container) (err error) {
+func (r *Runtime) createNetNS(ctr *Container) error {
 	return define.ErrNotImplemented
 }
 
diff --git a/libpod/oci_conmon_linux.go b/libpod/oci_conmon_linux.go
index 534622382..bd6af5281 100644
--- a/libpod/oci_conmon_linux.go
+++ b/libpod/oci_conmon_linux.go
@@ -191,7 +191,7 @@ func hasCurrentUserMapped(ctr *Container) bool {
 }
 
 // CreateContainer creates a container.
-func (r *ConmonOCIRuntime) CreateContainer(ctr *Container, restoreOptions *ContainerCheckpointOptions) (err error) {
+func (r *ConmonOCIRuntime) CreateContainer(ctr *Container, restoreOptions *ContainerCheckpointOptions) error {
 	if !hasCurrentUserMapped(ctr) {
 		for _, i := range []string{ctr.state.RunDir, ctr.runtime.config.Engine.TmpDir, ctr.config.StaticDir, ctr.state.Mountpoint, ctr.runtime.config.Engine.VolumePath} {
 			if err := makeAccessible(i, ctr.RootUID(), ctr.RootGID()); err != nil {
@@ -853,7 +853,7 @@ func (r *ConmonOCIRuntime) getLogTag(ctr *Container) (string, error) {
 }
 
 // createOCIContainer generates this container's main conmon instance and prepares it for starting
-func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *ContainerCheckpointOptions) (err error) {
+func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *ContainerCheckpointOptions) error {
 	var stderrBuf bytes.Buffer
 
 	runtimeDir, err := util.GetRuntimeDir()
@@ -1343,8 +1343,9 @@ func (r *ConmonOCIRuntime) moveConmonToCgroupAndSignal(ctr *Container, cmd *exec
 	return nil
 }
 
-// newPipe creates a unix socket pair for communication
-func newPipe() (parent *os.File, child *os.File, err error) {
+// newPipe creates a unix socket pair for communication.
+// Returns two files - first is parent, second is child.
+func newPipe() (*os.File, *os.File, error) {
 	fds, err := unix.Socketpair(unix.AF_LOCAL, unix.SOCK_SEQPACKET|unix.SOCK_CLOEXEC, 0)
 	if err != nil {
 		return nil, nil, err
diff --git a/libpod/runtime.go b/libpod/runtime.go
index 2575decc3..0075c0e13 100644
--- a/libpod/runtime.go
+++ b/libpod/runtime.go
@@ -126,7 +126,7 @@ func SetXdgDirs() error {
 
 // NewRuntime creates a new container runtime
 // Options can be passed to override the default configuration for the runtime
-func NewRuntime(ctx context.Context, options ...RuntimeOption) (runtime *Runtime, err error) {
+func NewRuntime(ctx context.Context, options ...RuntimeOption) (*Runtime, error) {
 	conf, err := config.NewConfig("")
 	if err != nil {
 		return nil, err
@@ -140,13 +140,13 @@ func NewRuntime(ctx context.Context, options ...RuntimeOption) (runtime *Runtime
 // functions can be used to mutate this configuration further.
 // An error will be returned if the configuration file at the given path does
 // not exist or cannot be loaded
-func NewRuntimeFromConfig(ctx context.Context, userConfig *config.Config, options ...RuntimeOption) (runtime *Runtime, err error) {
+func NewRuntimeFromConfig(ctx context.Context, userConfig *config.Config, options ...RuntimeOption) (*Runtime, error) {
 
 	return newRuntimeFromConfig(ctx, userConfig, options...)
 }
 
-func newRuntimeFromConfig(ctx context.Context, conf *config.Config, options ...RuntimeOption) (runtime *Runtime, err error) {
-	runtime = new(Runtime)
+func newRuntimeFromConfig(ctx context.Context, conf *config.Config, options ...RuntimeOption) (*Runtime, error) {
+	runtime := new(Runtime)
 
 	if conf.Engine.OCIRuntime == "" {
 		conf.Engine.OCIRuntime = "runc"
@@ -236,7 +236,7 @@ func getLockManager(runtime *Runtime) (lock.Manager, error) {
 
 // Make a new runtime based on the given configuration
 // Sets up containers/storage, state store, OCI runtime
-func makeRuntime(ctx context.Context, runtime *Runtime) (err error) {
+func makeRuntime(ctx context.Context, runtime *Runtime) (retErr error) {
 	// Find a working conmon binary
 	cPath, err := runtime.config.FindConmon()
 	if err != nil {
@@ -316,12 +316,11 @@ func makeRuntime(ctx context.Context, runtime *Runtime) (err error) {
 		return err
 	}
 	defer func() {
-		if err != nil && store != nil {
+		if retErr != nil && store != nil {
 			// Don't forcibly shut down
 			// We could be opening a store in use by another libpod
-			_, err2 := store.Shutdown(false)
-			if err2 != nil {
-				logrus.Errorf("Error removing store for partially-created runtime: %s", err2)
+			if _, err := store.Shutdown(false); err != nil {
+				logrus.Errorf("Error removing store for partially-created runtime: %s", err)
 			}
 		}
 	}()
diff --git a/libpod/runtime_ctr.go b/libpod/runtime_ctr.go
index e184df45d..d4508bf37 100644
--- a/libpod/runtime_ctr.go
+++ b/libpod/runtime_ctr.go
@@ -34,7 +34,7 @@ type CtrCreateOption func(*Container) error
 type ContainerFilter func(*Container) bool
 
 // NewContainer creates a new container from a given OCI config.
-func (r *Runtime) NewContainer(ctx context.Context, rSpec *spec.Spec, options ...CtrCreateOption) (c *Container, err error) {
+func (r *Runtime) NewContainer(ctx context.Context, rSpec *spec.Spec, options ...CtrCreateOption) (*Container, error) {
 	r.lock.Lock()
 	defer r.lock.Unlock()
 	if !r.valid {
@@ -44,7 +44,7 @@ func (r *Runtime) NewContainer(ctx context.Context, rSpec *spec.Spec, options ..
 }
 
 // RestoreContainer re-creates a container from an imported checkpoint
-func (r *Runtime) RestoreContainer(ctx context.Context, rSpec *spec.Spec, config *ContainerConfig) (c *Container, err error) {
+func (r *Runtime) RestoreContainer(ctx context.Context, rSpec *spec.Spec, config *ContainerConfig) (*Container, error) {
 	r.lock.Lock()
 	defer r.lock.Unlock()
 	if !r.valid {
@@ -68,7 +68,7 @@ func (r *Runtime) RestoreContainer(ctx context.Context, rSpec *spec.Spec, config
 	return r.setupContainer(ctx, ctr)
 }
 
-func (r *Runtime) initContainerVariables(rSpec *spec.Spec, config *ContainerConfig) (c *Container, err error) {
+func (r *Runtime) initContainerVariables(rSpec *spec.Spec, config *ContainerConfig) (*Container, error) {
 	if rSpec == nil {
 		return nil, errors.Wrapf(define.ErrInvalidArg, "must provide a valid runtime spec to create container")
 	}
@@ -122,7 +122,7 @@ func (r *Runtime) initContainerVariables(rSpec *spec.Spec, config *ContainerConf
 	return ctr, nil
 }
 
-func (r *Runtime) newContainer(ctx context.Context, rSpec *spec.Spec, options ...CtrCreateOption) (c *Container, err error) {
+func (r *Runtime) newContainer(ctx context.Context, rSpec *spec.Spec, options ...CtrCreateOption) (*Container, error) {
 	span, _ := opentracing.StartSpanFromContext(ctx, "newContainer")
 	span.SetTag("type", "runtime")
 	defer span.Finish()
@@ -141,7 +141,7 @@ func (r *Runtime) newContainer(ctx context.Context, rSpec *spec.Spec, options ..
 	return r.setupContainer(ctx, ctr)
 }
 
-func (r *Runtime) setupContainer(ctx context.Context, ctr *Container) (_ *Container, err error) {
+func (r *Runtime) setupContainer(ctx context.Context, ctr *Container) (_ *Container, retErr error) {
 	// Validate the container
 	if err := ctr.validate(); err != nil {
 		return nil, err
@@ -157,9 +157,9 @@ func (r *Runtime) setupContainer(ctx context.Context, ctr *Container) (_ *Contai
 	logrus.Debugf("Allocated lock %d for container %s", ctr.lock.ID(), ctr.ID())
 
 	defer func() {
-		if err != nil {
-			if err2 := ctr.lock.Free(); err2 != nil {
-				logrus.Errorf("Error freeing lock for container after creation failed: %v", err2)
+		if retErr != nil {
+			if err := ctr.lock.Free(); err != nil {
+				logrus.Errorf("Error freeing lock for container after creation failed: %v", err)
 			}
 		}
 	}()
@@ -272,9 +272,9 @@ func (r *Runtime) setupContainer(ctx context.Context, ctr *Container) (_ *Contai
 		return nil, err
 	}
 	defer func() {
-		if err != nil {
-			if err2 := ctr.teardownStorage(); err2 != nil {
-				logrus.Errorf("Error removing partially-created container root filesystem: %s", err2)
+		if retErr != nil {
+			if err := ctr.teardownStorage(); err != nil {
+				logrus.Errorf("Error removing partially-created container root filesystem: %s", err)
 			}
 		}
 	}()
diff --git a/libpod/state_test.go b/libpod/state_test.go
index 30ddf5e24..ef4f6f2be 100644
--- a/libpod/state_test.go
+++ b/libpod/state_test.go
@@ -34,13 +34,13 @@ var (
 )
 
 // Get an empty BoltDB state for use in tests
-func getEmptyBoltState() (s State, p string, m lock.Manager, err error) {
+func getEmptyBoltState() (_ State, _ string, _ lock.Manager, retErr error) {
 	tmpDir, err := ioutil.TempDir("", tmpDirPrefix)
 	if err != nil {
 		return nil, "", nil, err
 	}
 	defer func() {
-		if err != nil {
+		if retErr != nil {
 			os.RemoveAll(tmpDir)
 		}
 	}()
@@ -66,13 +66,13 @@ func getEmptyBoltState() (s State, p string, m lock.Manager, err error) {
 }
 
 // Get an empty in-memory state for use in tests
-func getEmptyInMemoryState() (s State, p string, m lock.Manager, err error) {
+func getEmptyInMemoryState() (_ State, _ string, _ lock.Manager, retErr error) {
 	tmpDir, err := ioutil.TempDir("", tmpDirPrefix)
 	if err != nil {
 		return nil, "", nil, err
 	}
 	defer func() {
-		if err != nil {
+		if retErr != nil {
 			os.RemoveAll(tmpDir)
 		}
 	}()
diff --git a/libpod/storage.go b/libpod/storage.go
index be79b3fc0..e497d0daf 100644
--- a/libpod/storage.go
+++ b/libpod/storage.go
@@ -66,7 +66,7 @@ func (metadata *RuntimeContainerMetadata) SetMountLabel(mountLabel string) {
 
 // CreateContainerStorage creates the storage end of things.  We already have the container spec created
 // TO-DO We should be passing in an Image object in the future.
-func (r *storageService) CreateContainerStorage(ctx context.Context, systemContext *types.SystemContext, imageName, imageID, containerName, containerID string, options storage.ContainerOptions) (cinfo ContainerInfo, err error) {
+func (r *storageService) CreateContainerStorage(ctx context.Context, systemContext *types.SystemContext, imageName, imageID, containerName, containerID string, options storage.ContainerOptions) (_ ContainerInfo, retErr error) {
 	span, _ := opentracing.StartSpanFromContext(ctx, "createContainerStorage")
 	span.SetTag("type", "storageService")
 	defer span.Finish()
@@ -132,9 +132,9 @@ func (r *storageService) CreateContainerStorage(ctx context.Context, systemConte
 	// If anything fails after this point, we need to delete the incomplete
 	// container before returning.
 	defer func() {
-		if err != nil {
-			if err2 := r.store.DeleteContainer(container.ID); err2 != nil {
-				logrus.Infof("%v deleting partially-created container %q", err2, container.ID)
+		if retErr != nil {
+			if err := r.store.DeleteContainer(container.ID); err != nil {
+				logrus.Infof("%v deleting partially-created container %q", err, container.ID)
 
 				return
 			}