enable gocritic linter

The linter ensures a common code style.
- use switch/case instead of else if
- use if instead of switch/case for single case statement
- add space between comment and text
- detect the use of defer with os.Exit()
- use short form var += "..." instead of var = var + "..."
- detect problems with append()
```
newSlice := append(orgSlice, val)
```
  This could lead to nasty bugs because the orgSlice will be changed in
  place if it has enough capacity too hold the new elements. Thus we
  newSlice might not be a copy.

Of course most of the changes are just cosmetic and do not cause any
logic errors but I think it is a good idea to enforce a common style.
This should help maintainability.

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

3 files changed, 9 insertions, 13 deletions

diff --git a/pkg/machine/config.go b/pkg/machine/config.go
index 1103933cd..5bbaf8c51 100644
--- a/pkg/machine/config.go
+++ b/pkg/machine/config.go
@@ -135,7 +135,7 @@ type InspectInfo struct {
 }
 
 func (rc RemoteConnectionType) MakeSSHURL(host, path, port, userName string) url.URL {
-	//TODO Should this function have input verification?
+	// TODO Should this function have input verification?
 	userInfo := url.User(userName)
 	uri := url.URL{
 		Scheme:     "ssh",
diff --git a/pkg/machine/fedora.go b/pkg/machine/fedora.go
index bed45c6da..14a173da6 100644
--- a/pkg/machine/fedora.go
+++ b/pkg/machine/fedora.go
@@ -21,6 +21,8 @@ const (
 	githubURL = "http://github.com/fedora-cloud/docker-brew-fedora/"
 )
 
+var fedoraxzRegex = regexp.MustCompile(`fedora[^\"]+xz`)
+
 type FedoraDownload struct {
 	Download
 }
@@ -96,12 +98,8 @@ func getFedoraDownload(releaseStream string) (string, *url.URL, int64, error) {
 		return "", nil, -1, err
 	}
 
-	rx, err := regexp.Compile(`fedora[^\"]+xz`)
-	if err != nil {
-		return "", nil, -1, err
-	}
-	file := rx.FindString(string(body))
-	if len(file) <= 0 {
+	file := fedoraxzRegex.FindString(string(body))
+	if len(file) == 0 {
 		return "", nil, -1, fmt.Errorf("could not locate Fedora download at %s", dirURL)
 	}
 
diff --git a/pkg/machine/qemu/machine.go b/pkg/machine/qemu/machine.go
index 969acb760..5481bad29 100644
--- a/pkg/machine/qemu/machine.go
+++ b/pkg/machine/qemu/machine.go
@@ -332,8 +332,7 @@ func (v *MachineVM) Init(opts machine.InitOptions) (bool, error) {
 				}
 			}
 		}
-		switch volumeType {
-		case VolumeTypeVirtfs:
+		if volumeType == VolumeTypeVirtfs {
 			virtfsOptions := fmt.Sprintf("local,path=%s,mount_tag=%s,security_model=mapped-xattr", source, tag)
 			if readonly {
 				virtfsOptions += ",readonly"
@@ -783,7 +782,7 @@ func (v *MachineVM) Stop(_ string, _ machine.StopOptions) error {
 			break
 		}
 		time.Sleep(waitInternal)
-		waitInternal = waitInternal * 2
+		waitInternal *= 2
 	}
 
 	return v.ReadySocket.Delete()
@@ -799,8 +798,7 @@ func NewQMPMonitor(network, name string, timeout time.Duration) (Monitor, error)
 		rtDir = "/run"
 	}
 	rtDir = filepath.Join(rtDir, "podman")
-	if _, err := os.Stat(filepath.Join(rtDir)); os.IsNotExist(err) {
-		// TODO 0644 is fine on linux but macos is weird
+	if _, err := os.Stat(rtDir); os.IsNotExist(err) {
 		if err := os.MkdirAll(rtDir, 0755); err != nil {
 			return Monitor{}, err
 		}
@@ -872,7 +870,7 @@ func (v *MachineVM) Remove(_ string, opts machine.RemoveOptions) (string, func()
 		confirmationMessage += msg + "\n"
 	}
 
-	//remove socket and pid file if any: warn at low priority if things fail
+	// remove socket and pid file if any: warn at low priority if things fail
 	// Remove the pidfile
 	if err := v.PidFilePath.Delete(); err != nil {
 		logrus.Debugf("Error while removing pidfile: %v", err)