installpkg: only untar what is needed

Avoid unarchiving the package's '/install' directory.  Required files from
the directory are installed already into the system's package database.

1 files changed, 13 insertions, 42 deletions

diff --git a/installpkg.go b/installpkg.go
index 7e10e61..82532a9 100644
--- a/installpkg.go
+++ b/installpkg.go
@@ -6,9 +6,7 @@ import (
 	"io"
 	"os"
 	"os/exec"
-	"path"
 	"path/filepath"
-	"strings"
 	"time"
 
 	"github.com/juju/fslock"
@@ -101,12 +99,10 @@ func (s *InstallPkgFlags) SetEnvValues() {
 	}
 }
 
-func runInstallScript(flags *InstallPkgFlags, installPath string) error {
-	installPath, err := filepath.Abs(installPath)
-	if err != nil {
-		return err
-	}
-
+func runInstallScript(
+	flags *InstallPkgFlags,
+	pkgBase string,
+) error {
 	l := fslock.New(FileLockPath(flags.LockDir, filepath.Base(PackageInstallScript)))
 	if err := l.Lock(); err != nil {
 		return err
@@ -123,7 +119,7 @@ func runInstallScript(flags *InstallPkgFlags, installPath string) error {
 	}
 	defer os.Chdir(cwd)
 
-	installScript := path.Join(installPath, filepath.Base(PackageInstallScript))
+	installScript := filepath.Join(flags.Root, ADMDir, "scripts", pkgBase)
 	if _, err := os.Stat(installScript); !os.IsNotExist(err) {
 		cmd := exec.Command("/bin/bash", installScript)
 		cmd.Stdin = os.Stdout
@@ -294,13 +290,13 @@ func writeToDatabase(target string, pkg string) error {
 	return nil
 }
 
-// ExtractSlackwarePkg unarchives the slackware package into the given
+// extractSlackwarePkg unarchives the slackware package into the given
 // directory.  The package metadata, under the archives '/install' path, is put
 // into a temporary directory and returned.
-func ExtractSlackwarePkg(flags *InstallPkgFlags, fp string) (string, error) {
+func extractSlackwarePkg(flags *InstallPkgFlags, fp string) error {
 	slackPkg, err := OpenSlackwarePkg(fp)
 	if err != nil {
-		return "", errors.Wrap(err, "extracting package")
+		return errors.Wrap(err, "extracting package")
 	}
 	defer slackPkg.Close()
 
@@ -310,31 +306,12 @@ func ExtractSlackwarePkg(flags *InstallPkgFlags, fp string) (string, error) {
 		Chown: flags.chown,
 	})
 
-	tmpDir := os.TempDir()
-	if _, err := os.Stat(tmpDir); os.IsNotExist(err) {
-		tmpDir = "/"
-	} else if err != nil {
-		return "", errors.Wrap(err, "extracting package")
-	}
-	tempInstallDir, err := os.MkdirTemp(tmpDir, "installpkg-*")
-	if err != nil {
-		return "", errors.Wrap(err, "extracting package")
-	}
-	toTempInstallDir := NewTarExtractor(&TarCfg{
-		Root:  tempInstallDir,
-		Chmod: flags.chmod,
-		Chown: flags.chown,
-	})
-
 	err = FilterTar(
 		slackPkg,
 		TarFilterFunc(func(h *tar.Header, r io.Reader) error {
 			if ok, err := IsParentDir(PackageInstallPath, h.Name); ok {
-				h.Name = strings.TrimPrefix(h.Name, PackageInstallPath+"/")
-				if h.Name == "" {
-					h.Name = "."
-				}
-				return toTempInstallDir.FilterTar(h, r)
+				// important install files are already written
+				// to the targets package database.
 			} else if err != nil {
 				return errors.Wrap(err, "installing package")
 			}
@@ -342,7 +319,7 @@ func ExtractSlackwarePkg(flags *InstallPkgFlags, fp string) (string, error) {
 			return toRoot.FilterTar(h, r)
 		}),
 	)
-	return tempInstallDir, errors.Wrap(err, "installing package")
+	return errors.Wrap(err, "installing package")
 }
 
 func InstallPkg(flags *InstallPkgFlags, pkgs ...string) error {
@@ -360,7 +337,7 @@ func InstallPkg(flags *InstallPkgFlags, pkgs ...string) error {
 			return errors.Wrap(err, "writing package to database")
 		}
 
-		installPath, err := ExtractSlackwarePkg(flags, pkg)
+		err := extractSlackwarePkg(flags, pkg)
 		if err != nil {
 			return errors.Wrap(err, "writing package to database")
 		}
@@ -373,16 +350,10 @@ func InstallPkg(flags *InstallPkgFlags, pkgs ...string) error {
 
 		_ = runLDConfig(flags.LockDir)
 
-		// TODO: command should still run after failed 'install script' execution
-		err = runInstallScript(flags, installPath)
+		err = runInstallScript(flags, PackageBase(pkg))
 		if err != nil {
 			fmt.Fprintln(os.Stderr, errors.Wrap(err, "running install script"))
 		}
-
-		err = os.RemoveAll(installPath)
-		if err != nil {
-			return err
-		}
 	}
 
 	return nil