Fix problems reported by staticcheck

`staticcheck` is a golang code analysis tool. https://staticcheck.io/

This commit fixes a lot of problems found in our code. Common problems are:
- unnecessary use of fmt.Sprintf
- duplicated imports with different names
- unnecessary check that a key exists before a delete call

There are still a lot of reported problems in the test files but I have
not looked at those.

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

12 files changed, 13 insertions, 44 deletions

diff --git a/pkg/api/handlers/libpod/images.go b/pkg/api/handlers/libpod/images.go
index 979a8adc4..b2b93de17 100644
--- a/pkg/api/handlers/libpod/images.go
+++ b/pkg/api/handlers/libpod/images.go
@@ -16,7 +16,6 @@ import (
 	"github.com/containers/podman/v2/libpod"
 	"github.com/containers/podman/v2/libpod/define"
 	"github.com/containers/podman/v2/libpod/image"
-	image2 "github.com/containers/podman/v2/libpod/image"
 	"github.com/containers/podman/v2/pkg/api/handlers"
 	"github.com/containers/podman/v2/pkg/api/handlers/utils"
 	"github.com/containers/podman/v2/pkg/auth"
@@ -524,7 +523,7 @@ func CommitContainer(w http.ResponseWriter, r *http.Request) {
 		utils.Error(w, "failed to get runtime config", http.StatusInternalServerError, errors.Wrap(err, "failed to get runtime config"))
 		return
 	}
-	sc := image2.GetSystemContext(rtc.Engine.SignaturePolicyPath, "", false)
+	sc := image.GetSystemContext(rtc.Engine.SignaturePolicyPath, "", false)
 	tag := "latest"
 	options := libpod.ContainerCommitOptions{
 		Pause: true,
diff --git a/pkg/domain/filters/containers.go b/pkg/domain/filters/containers.go
index 09ef6201a..1de5aca91 100644
--- a/pkg/domain/filters/containers.go
+++ b/pkg/domain/filters/containers.go
@@ -35,7 +35,7 @@ func GenerateContainerFilterFuncs(filter string, filterValues []string, r *libpo
 					filterValue = ""
 				}
 				for labelKey, labelValue := range labels {
-					if labelKey == filterKey && ("" == filterValue || labelValue == filterValue) {
+					if labelKey == filterKey && (filterValue == "" || labelValue == filterValue) {
 						matched = true
 						break
 					}
diff --git a/pkg/domain/filters/pods.go b/pkg/domain/filters/pods.go
index 685c182ba..ce7028d2a 100644
--- a/pkg/domain/filters/pods.go
+++ b/pkg/domain/filters/pods.go
@@ -124,7 +124,7 @@ func GeneratePodFilterFunc(filter string, filterValues []string) (
 					filterValue = ""
 				}
 				for labelKey, labelValue := range labels {
-					if labelKey == filterKey && ("" == filterValue || labelValue == filterValue) {
+					if labelKey == filterKey && (filterValue == "" || labelValue == filterValue) {
 						matched = true
 						break
 					}
diff --git a/pkg/domain/filters/volumes.go b/pkg/domain/filters/volumes.go
index 69bef4961..7890459f5 100644
--- a/pkg/domain/filters/volumes.go
+++ b/pkg/domain/filters/volumes.go
@@ -39,7 +39,7 @@ func GenerateVolumeFilters(filters url.Values) ([]libpod.VolumeFilter, error) {
 				}
 				vf = append(vf, func(v *libpod.Volume) bool {
 					for labelKey, labelValue := range v.Labels() {
-						if labelKey == filterKey && ("" == filterVal || labelValue == filterVal) {
+						if labelKey == filterKey && (filterVal == "" || labelValue == filterVal) {
 							return true
 						}
 					}
@@ -56,7 +56,7 @@ func GenerateVolumeFilters(filters url.Values) ([]libpod.VolumeFilter, error) {
 				}
 				vf = append(vf, func(v *libpod.Volume) bool {
 					for labelKey, labelValue := range v.Options() {
-						if labelKey == filterKey && ("" == filterVal || labelValue == filterVal) {
+						if labelKey == filterKey && (filterVal == "" || labelValue == filterVal) {
 							return true
 						}
 					}
diff --git a/pkg/domain/infra/abi/containers.go b/pkg/domain/infra/abi/containers.go
index f7a538934..620f05192 100644
--- a/pkg/domain/infra/abi/containers.go
+++ b/pkg/domain/infra/abi/containers.go
@@ -113,15 +113,7 @@ func (ic *ContainerEngine) ContainerWait(ctx context.Context, namesOrIds []strin
 }
 
 func (ic *ContainerEngine) ContainerPause(ctx context.Context, namesOrIds []string, options entities.PauseUnPauseOptions) ([]*entities.PauseUnpauseReport, error) {
-	var (
-		err error
-	)
-	ctrs := []*libpod.Container{} //nolint
-	if options.All {
-		ctrs, err = ic.Libpod.GetAllContainers()
-	} else {
-		ctrs, err = getContainersByContext(false, false, namesOrIds, ic.Libpod)
-	}
+	ctrs, err := getContainersByContext(options.All, false, namesOrIds, ic.Libpod)
 	if err != nil {
 		return nil, err
 	}
@@ -134,15 +126,7 @@ func (ic *ContainerEngine) ContainerPause(ctx context.Context, namesOrIds []stri
 }
 
 func (ic *ContainerEngine) ContainerUnpause(ctx context.Context, namesOrIds []string, options entities.PauseUnPauseOptions) ([]*entities.PauseUnpauseReport, error) {
-	var (
-		err error
-	)
-	ctrs := []*libpod.Container{} //nolint
-	if options.All {
-		ctrs, err = ic.Libpod.GetAllContainers()
-	} else {
-		ctrs, err = getContainersByContext(false, false, namesOrIds, ic.Libpod)
-	}
+	ctrs, err := getContainersByContext(options.All, false, namesOrIds, ic.Libpod)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/domain/infra/abi/images.go b/pkg/domain/infra/abi/images.go
index 19f081abb..3487dc3f4 100644
--- a/pkg/domain/infra/abi/images.go
+++ b/pkg/domain/infra/abi/images.go
@@ -22,7 +22,6 @@ import (
 	"github.com/containers/image/v5/types"
 	"github.com/containers/podman/v2/libpod/define"
 	"github.com/containers/podman/v2/libpod/image"
-	libpodImage "github.com/containers/podman/v2/libpod/image"
 	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/containers/podman/v2/pkg/domain/entities/reports"
 	domainUtils "github.com/containers/podman/v2/pkg/domain/utils"
@@ -206,7 +205,7 @@ func (ir *ImageEngine) Unmount(ctx context.Context, nameOrIDs []string, options
 	return reports, nil
 }
 
-func ToDomainHistoryLayer(layer *libpodImage.History) entities.ImageHistoryLayer {
+func ToDomainHistoryLayer(layer *image.History) entities.ImageHistoryLayer {
 	l := entities.ImageHistoryLayer{}
 	l.ID = layer.ID
 	l.Created = *layer.Created
diff --git a/pkg/domain/infra/abi/manifest.go b/pkg/domain/infra/abi/manifest.go
index 0c734d10d..a68ed8788 100644
--- a/pkg/domain/infra/abi/manifest.go
+++ b/pkg/domain/infra/abi/manifest.go
@@ -13,7 +13,6 @@ import (
 
 	"github.com/containers/buildah/manifests"
 	buildahManifests "github.com/containers/buildah/pkg/manifests"
-	"github.com/containers/buildah/util"
 	buildahUtil "github.com/containers/buildah/util"
 	cp "github.com/containers/image/v5/copy"
 	"github.com/containers/image/v5/docker"
@@ -60,7 +59,7 @@ func (ir *ImageEngine) ManifestInspect(ctx context.Context, name string) ([]byte
 		}
 	}
 	sc := ir.Libpod.SystemContext()
-	refs, err := util.ResolveNameToReferences(ir.Libpod.GetStore(), sc, name)
+	refs, err := buildahUtil.ResolveNameToReferences(ir.Libpod.GetStore(), sc, name)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/domain/infra/abi/system.go b/pkg/domain/infra/abi/system.go
index 67c018122..97fa9d374 100644
--- a/pkg/domain/infra/abi/system.go
+++ b/pkg/domain/infra/abi/system.go
@@ -162,11 +162,6 @@ func movePauseProcessToScope(r *libpod.Runtime) error {
 	return utils.RunUnderSystemdScope(int(pid), "user.slice", "podman-pause.scope")
 }
 
-// checkInput can be used to verify any of the globalopt values
-func checkInput() error { // nolint:deadcode,unused
-	return nil
-}
-
 // SystemPrune removes unused data from the system. Pruning pods, containers, volumes and images.
 func (ic *ContainerEngine) SystemPrune(ctx context.Context, options entities.SystemPruneOptions) (*entities.SystemPruneReport, error) {
 	var systemPruneReport = new(entities.SystemPruneReport)
diff --git a/pkg/specgen/generate/config_linux.go b/pkg/specgen/generate/config_linux.go
index e0b039fb7..1290a8eb6 100644
--- a/pkg/specgen/generate/config_linux.go
+++ b/pkg/specgen/generate/config_linux.go
@@ -21,9 +21,6 @@ var (
 	errNotADevice = errors.New("not a device node")
 )
 
-func u32Ptr(i int64) *uint32     { u := uint32(i); return &u }
-func fmPtr(i int64) *os.FileMode { fm := os.FileMode(i); return &fm }
-
 func addPrivilegedDevices(g *generate.Generator) error {
 	hostDevices, err := getDevices("/dev")
 	if err != nil {
diff --git a/pkg/specgen/generate/oci.go b/pkg/specgen/generate/oci.go
index ba68de6fd..7dc32a314 100644
--- a/pkg/specgen/generate/oci.go
+++ b/pkg/specgen/generate/oci.go
@@ -110,7 +110,7 @@ func makeCommand(ctx context.Context, s *specgen.SpecGenerator, img *image.Image
 	// Only use image command if the user did not manually set an
 	// entrypoint.
 	command := s.Command
-	if (command == nil || len(command) == 0) && img != nil && (s.Entrypoint == nil || len(s.Entrypoint) == 0) {
+	if len(command) == 0 && img != nil && len(s.Entrypoint) == 0 {
 		newCmd, err := img.Cmd(ctx)
 		if err != nil {
 			return nil, err
diff --git a/pkg/specgen/generate/storage.go b/pkg/specgen/generate/storage.go
index f523ac5bf..63713726e 100644
--- a/pkg/specgen/generate/storage.go
+++ b/pkg/specgen/generate/storage.go
@@ -124,14 +124,10 @@ func finalizeMounts(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.Ru
 	// named volumes, and vice versa.
 	// We'll delete the conflicts here as we supersede.
 	for dest := range unifiedMounts {
-		if _, ok := baseVolumes[dest]; ok {
-			delete(baseVolumes, dest)
-		}
+		delete(baseVolumes, dest)
 	}
 	for dest := range unifiedVolumes {
-		if _, ok := baseMounts[dest]; ok {
-			delete(baseMounts, dest)
-		}
+		delete(baseMounts, dest)
 	}
 
 	// Supersede volumes-from/image volumes with unified volumes from above.
diff --git a/pkg/specgen/generate/validate.go b/pkg/specgen/generate/validate.go
index f0ab4b994..77cccad3e 100644
--- a/pkg/specgen/generate/validate.go
+++ b/pkg/specgen/generate/validate.go
@@ -48,7 +48,7 @@ func verifyContainerResourcesCgroupV1(s *specgen.SpecGenerator) ([]string, error
 				warnings = append(warnings, "Your kernel does not support memory swappiness capabilities, or the cgroup is not mounted. Memory swappiness discarded.")
 				memory.Swappiness = nil
 			} else {
-				if *memory.Swappiness < 0 || *memory.Swappiness > 100 {
+				if *memory.Swappiness > 100 {
 					return warnings, errors.Errorf("invalid value: %v, valid memory swappiness range is 0-100", *memory.Swappiness)
 				}
 			}