[BZ #2083997] pod: build pause image in custom user NS

Use the host UID and host GID mapping when building the local pause
image for a Pod with a custom mapping.  Otherwise, the mappings are off
and the build fails. Propagating the mapping to the build container is
not needed since the pause image ships merely a copied `catatonit` from
the host.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2083997
Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>

pkg/specgen/generate/pause_image.go

@@ -80,6 +80,12 @@ ENTRYPOINT ["/catatonit", "-P"]`, catatonitPath)
 		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