import: move bib files to correct path

Moves the files imported from `bootc-image-builder` to the appropriate
path under `pkg/` so they can be imported reverse. Also fix up the
import paths that are in these files to refer to their new locations.

Signed-off-by: Simon de Vlieger <supakeen@redhat.com>

pkg/setup/setup.go

@@ -0,0 +1,167 @@
+package setup
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"golang.org/x/sys/unix"
+
+	"github.com/sirupsen/logrus"
+
+	"github.com/osbuild/image-builder-cli/pkg/podmanutil"
+	"github.com/osbuild/image-builder-cli/pkg/util"
+)
+
+// EnsureEnvironment mutates external filesystem state as necessary
+// to run in a container environment.  This function is idempotent.
+func EnsureEnvironment(storePath string) error {
+	osbuildPath := "/usr/bin/osbuild"
+	if util.IsMountpoint(osbuildPath) {
+		return nil
+	}
+
+	// Forcibly label the store to ensure we're not grabbing container labels
+	rootType := "system_u:object_r:root_t:s0"
+	// This papers over the lack of ensuring correct labels for the /ostree root
+	// in the existing pipeline
+	if err := util.RunCmdSync("chcon", rootType, storePath); err != nil {
+		return err
+	}
+
+	// A hardcoded security label from Fedora derivatives for osbuild
+	// TODO: Avoid hardcoding this by using either host policy lookup
+	// Or eventually depend on privileged containers just having this capability.
+	//
+	// We need this in order to get `install_t` that has `CAP_MAC_ADMIN` for creating SELinux
+	// labels unknown to the host.
+	//
+	// Note that the transition to `install_t` must happen at this point. Osbuild stages run in `bwrap` that creates
+	// a nosuid, no_new_privs environment. In such an environment, we cannot transition from `unconfined_t` to `install_t`,
+	// because we would get more privileges.
+	installType := "system_u:object_r:install_exec_t:s0"
+	// Where we dump temporary files; this must be an overlayfs as we cannot
+	// write security contexts on overlayfs.
+	runTmp := "/run/osbuild/"
+
+	if err := os.MkdirAll(runTmp, 0o755); err != nil {
+		return err
+	}
+	if !util.IsMountpoint(runTmp) {
+		if err := util.RunCmdSync("mount", "-t", "tmpfs", "tmpfs", runTmp); err != nil {
+			return err
+		}
+	}
+	destPath := filepath.Join(runTmp, "osbuild")
+	if err := util.RunCmdSync("cp", "-p", "/usr/bin/osbuild", destPath); err != nil {
+		return err
+	}
+	if err := util.RunCmdSync("chcon", installType, destPath); err != nil {
+		return err
+	}
+
+	// Ensure we have devfs inside the container to get dynamic loop
+	// loop devices inside the container.
+	if err := util.RunCmdSync("mount", "-t", "devtmpfs", "devtmpfs", "/dev"); err != nil {
+		return err
+	}
+
+	// Create a bind mount into our target location; we can't copy it because
+	// again we have to perserve the SELinux label.
+	if err := util.RunCmdSync("mount", "--bind", destPath, osbuildPath); err != nil {
+		return err
+	}
+	// NOTE: Don't add new code here, do it before the bind mount which acts as the final success indicator
+
+	return nil
+}
+
+// Validate checks that the environment is supported (e.g. caller set up the
+// container correctly)
+func Validate(targetArch string) error {
+	isRootless, err := podmanutil.IsRootless()
+	if err != nil {
+		return fmt.Errorf("checking rootless: %w", err)
+	}
+	if isRootless {
+		return fmt.Errorf("this command must be run in rootful (not rootless) podman")
+	}
+
+	// Having /sys be writable is an easy to check proxy for privileges; more effective
+	// is really looking for CAP_SYS_ADMIN, but that involves more Go libraries.
+	var stvfsbuf unix.Statfs_t
+	if err := unix.Statfs("/sys", &stvfsbuf); err != nil {
+		return fmt.Errorf("failed to stat /sys: %w", err)
+	}
+	if (stvfsbuf.Flags & unix.ST_RDONLY) > 0 {
+		return fmt.Errorf("this command requires a privileged container")
+	}
+
+	// Try to run the cross arch binary
+	if err := validateCanRunTargetArch(targetArch); err != nil {
+		return fmt.Errorf("cannot run binary in target arch: %w", err)
+	}
+
+	return nil
+}
+
+// ValidateHasContainerStorageMounted checks that the hostcontainer storage
+// is mounted inside the container
+func ValidateHasContainerStorageMounted() error {
+	// Just look for the overlay backend, which we expect by default.
+	// In theory, one could be using a different backend, but we don't
+	// really need to worry about this right now.  If it turns out
+	// we do need to care, then we can probably handle this by
+	// just trying to query the image.
+	overlayPath := "/var/lib/containers/storage/overlay"
+	if _, err := os.Stat(overlayPath); err != nil {
+		if os.IsNotExist(err) {
+			return fmt.Errorf("cannot find %q (missing -v /var/lib/containers/storage:/var/lib/containers/storage mount?)", overlayPath)
+		}
+		return fmt.Errorf("failed to stat %q: %w", overlayPath, err)
+	}
+	return nil
+}
+
+func validateCanRunTargetArch(targetArch string) error {
+	if targetArch == runtime.GOARCH || targetArch == "" {
+		return nil
+	}
+
+	canaryCmd := fmt.Sprintf("bib-canary-%s", targetArch)
+	if _, err := exec.LookPath(canaryCmd); err != nil {
+		// we could error here but in principle with a working qemu-user
+		// any arch should work so let's just warn. the common case
+		// (arm64/amd64) is covered properly
+		logrus.Warningf("cannot check architecture support for %v: no canary binary found", targetArch)
+		return nil
+	}
+	output, err := exec.Command(canaryCmd).CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("cannot run canary binary for %q, do you have 'qemu-user-static' installed?\n%s", targetArch, err)
+	}
+	if string(output) != "ok\n" {
+		return fmt.Errorf("internal error: unexpected output from cross-architecture canary: %q", string(output))
+	}
+
+	return nil
+}
+
+func ValidateHasContainerTags(imgref string) error {
+	output, err := exec.Command("podman", "image", "inspect", imgref, "--format", "{{.Labels}}").Output()
+	if err != nil {
+		return fmt.Errorf(`failed to inspect the image: %w
+bootc-image-builder no longer pulls images, make sure to pull it before running bootc-image-builder:
+    sudo podman pull %s`, util.OutputErr(err), imgref)
+	}
+
+	tags := string(output)
+	if !strings.Contains(tags, "containers.bootc:1") {
+		return fmt.Errorf("image %s is not a bootc image", imgref)
+	}
+
+	return nil
+}