Replace podman pause image with rootfs.

This commit removes the code to build a local pause
image from the Containerfile. It is replaced with
code to find the catatonit binary and include it in
the Rootfs.

This removes the need to build a local pause container
image.

The same logic is also applied to createServiceContainer
which is originally also based on the pause image.

Fixes: #23292

Signed-off-by: Jan Kaluza <jkaluza@redhat.com>

pkg/specgen/generate/kube/kube.go

@@ -301,9 +301,13 @@ func ToSpecGen(ctx context.Context, opts *CtrSpecGenOptions) (*specgen.SpecGener
 
 	// TODO: We don't understand why specgen does not take of this, but
 	// integration tests clearly pointed out that it was required.
-	imageData, err := opts.Image.Inspect(ctx, nil)
-	if err != nil {
-		return nil, err
+	var imageData *libimage.ImageData
+	if opts.Image != nil {
+		var err error
+		imageData, err = opts.Image.Inspect(ctx, nil)
+		if err != nil {
+			return nil, err
+		}
 	}
 	s.WorkDir = "/"
 	// Entrypoint/Command handling is based off of

pkg/specgen/generate/pause_image.go

@@ -4,18 +4,15 @@ package generate
 
 import (
 	"context"
-	"fmt"
-	"os"
 
-	buildahDefine "github.com/containers/buildah/define"
 	"github.com/containers/common/pkg/config"
 	"github.com/containers/podman/v5/libpod"
-	"github.com/containers/podman/v5/libpod/define"
 )
 
-// PullOrBuildInfraImage pulls down the specified image or the one set in
-// containers.conf.  If none is set, it builds a local pause image.
-func PullOrBuildInfraImage(rt *libpod.Runtime, imageName string) (string, error) {
+// PullInfraImage pulls down the specified image or the one set in
+// containers.conf. If none is set, it returns an empty string. In this
+// case, the rootfs-based pause image is used by libpod.
+func PullInfraImage(rt *libpod.Runtime, imageName string) (string, error) {
 	rtConfig, err := rt.GetConfigNoCopy()
 	if err != nil {
 		return "", err
@@ -33,64 +30,5 @@ func PullOrBuildInfraImage(rt *libpod.Runtime, imageName string) (string, error)
 		return imageName, nil
 	}
 
-	name, err := buildPauseImage(rt, rtConfig)
-	if err != nil {
-		return "", fmt.Errorf("building local pause image: %w", err)
-	}
-	return name, nil
-}
-
-func buildPauseImage(rt *libpod.Runtime, rtConfig *config.Config) (string, error) {
-	version, err := define.GetVersion()
-	if err != nil {
-		return "", err
-	}
-	imageName := fmt.Sprintf("localhost/podman-pause:%s-%d", version.Version, version.Built)
-
-	// First check if the image has already been built.
-	if _, _, err := rt.LibimageRuntime().LookupImage(imageName, nil); err == nil {
-		return imageName, nil
-	}
-
-	// Also look into the path as some distributions install catatonit in
-	// /usr/bin.
-	catatonitPath, err := rtConfig.FindInitBinary()
-	if err != nil {
-		return "", fmt.Errorf("finding pause binary: %w", err)
-	}
-
-	buildContent := fmt.Sprintf(`FROM scratch
-COPY %s /catatonit
-ENTRYPOINT ["/catatonit", "-P"]`, catatonitPath)
-
-	tmpF, err := os.CreateTemp("", "pause.containerfile")
-	if err != nil {
-		return "", err
-	}
-	if _, err := tmpF.WriteString(buildContent); err != nil {
-		return "", err
-	}
-	if err := tmpF.Close(); err != nil {
-		return "", err
-	}
-	defer os.Remove(tmpF.Name())
-
-	buildOptions := buildahDefine.BuildOptions{
-		CommonBuildOpts: &buildahDefine.CommonBuildOptions{},
-		Output:          imageName,
-		Quiet:           true,
-		IgnoreFile:      "/dev/null", // makes sure to not read a local .ignorefile (see #13529)
-		IIDFile:         "/dev/null", // prevents Buildah from writing the ID on stdout
-		IDMappingOptions: &buildahDefine.IDMappingOptions{
-			// Use the host UID/GID mappings for the build to avoid issues when
-			// running with a custom mapping (BZ #2083997).
-			HostUIDMapping: true,
-			HostGIDMapping: true,
-		},
-	}
-	if _, _, err := rt.Build(context.Background(), buildOptions, tmpF.Name()); err != nil {
-		return "", err
-	}
-
-	return imageName, nil
+	return "", nil
 }

pkg/specgen/generate/pod_create.go

@@ -38,12 +38,14 @@ func MakePod(p *entities.PodSpec, rt *libpod.Runtime) (_ *libpod.Pod, finalErr e
 	}
 
 	if !p.PodSpecGen.NoInfra {
-		imageName, err := PullOrBuildInfraImage(rt, p.PodSpecGen.InfraImage)
+		imageName, err := PullInfraImage(rt, p.PodSpecGen.InfraImage)
 		if err != nil {
 			return nil, err
 		}
-		p.PodSpecGen.InfraImage = imageName
-		p.PodSpecGen.InfraContainerSpec.RawImageName = imageName
+		if len(imageName) > 0 {
+			p.PodSpecGen.InfraImage = imageName
+			p.PodSpecGen.InfraContainerSpec.RawImageName = imageName
+		}
 	}
 
 	spec, err := MapSpec(&p.PodSpecGen)