Merge pull request #12 from rmohr/sandbox

Prepare bazeldnf for creating sandboxes for bazel

cmd/BUILD.bazel

@@ -14,6 +14,7 @@ go_library(
         "root.go",
         "rpm2tar.go",
         "rpmtree.go",
+        "sandbox.go",
         "tar2files.go",
         "verify.go",
     ],

cmd/ldd.go

@@ -54,10 +54,6 @@ func NewLddCmd() *cobra.Command {
 			}
 			for _, dep := range dependencies {
 				if strings.HasPrefix(dep, tmpRoot) {
-					if strings.HasPrefix(filepath.Base(dep), "ld-") {
-						// don't link against ld itself
-						continue
-					}
 					files = append(files, strings.TrimPrefix(dep, tmpRoot))
 				}
 			}

cmd/root.go

@@ -16,6 +16,7 @@ var rootCmd = &cobra.Command{
 }
 
 func Execute() {
+	rootCmd.AddCommand(NewSandboxCmd())
 	rootCmd.AddCommand(NewFetchCmd())
 	rootCmd.AddCommand(NewInitCmd())
 	rootCmd.AddCommand(NewRpmTreeCmd())

cmd/sandbox.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/rmohr/bazeldnf/pkg/rpm"
+	"github.com/spf13/cobra"
+)
+
+type sandboxOpts struct {
+	tar         string
+	sandboxRoot string
+	name        string
+}
+
+var sandboxopts = sandboxOpts{}
+
+func NewSandboxCmd() *cobra.Command {
+
+	sandboxCmd := &cobra.Command{
+		Use:   "sandbox",
+		Short: "Extract a set of RPMs to a specific location",
+		RunE: func(cmd *cobra.Command, objects []string) error {
+			rootDir := filepath.Join(sandboxopts.sandboxRoot, "sandbox", sandboxopts.name, "root")
+			if err := os.RemoveAll(rootDir); err != nil {
+				return fmt.Errorf("failed to do the initial cleanup on the sandbox: %v", err)
+			}
+			if err := os.MkdirAll(rootDir, os.ModePerm); err != nil {
+				return fmt.Errorf("failed to create the sandbox base directory: %v", err)
+			}
+			return rpm.Untar(rootDir, sandboxopts.tar)
+		},
+	}
+
+	sandboxCmd.Flags().StringVarP(&sandboxopts.tar, "input", "i", "", "Tar file with all dependencies")
+	sandboxCmd.Flags().StringVar(&sandboxopts.sandboxRoot, "sandbox", ".bazeldnf", "Root directory of the sandbox")
+	sandboxCmd.Flags().StringVarP(&sandboxopts.name, "name", "n", "default", "Sandbox name")
+	return sandboxCmd
+}

internal/bazeldnf.bzl

@@ -1,6 +1,7 @@
 load("@bazel_skylib//lib:shell.bzl", "shell")
 
 def _bazeldnf_impl(ctx):
+    transitive_dependencies = []
     out_file = ctx.actions.declare_file(ctx.label.name + ".bash")
     args = []
     if ctx.attr.command:
@@ -11,6 +12,7 @@ def _bazeldnf_impl(ctx):
         args += ["--rpmtree", ctx.attr.rpmtree]
     if ctx.file.tar:
         args += ["-i", ctx.file.tar.path]
+        transitive_dependencies += [ctx.attr.tar.files]
     for lib in ctx.attr.libs:
         args += [lib]
 
@@ -24,7 +26,10 @@ def _bazeldnf_impl(ctx):
         substitutions = substitutions,
         is_executable = True,
     )
-    runfiles = ctx.runfiles(files = [ctx.executable._bazeldnf])
+    runfiles = ctx.runfiles(
+        files = [ctx.executable._bazeldnf],
+        transitive_files = depset([], transitive = transitive_dependencies),
+    )
     return [DefaultInfo(
         files = depset([out_file]),
         runfiles = runfiles,
@@ -38,6 +43,7 @@ _bazeldnf = rule(
             values = [
                 "",
                 "ldd",
+                "sandbox",
             ],
             default = "",
         ),

pkg/rpm/tar.go

@@ -118,6 +118,7 @@ func Untar(tmpRoot string, tarFile string) error {
 	}
 	defer reader.Close()
 	tarReader := tar.NewReader(reader)
+	hardLinks := map[string]string{}
 
 	for {
 		entry, err := tarReader.Next()
@@ -150,9 +151,12 @@ func Untar(tmpRoot string, tarFile string) error {
 				if err != nil {
 					return err
 				}
+				defer writer.Close()
 				if _, err := io.Copy(writer, tarReader); err != nil {
 					return err
 				}
+				writer.Close()
+				os.Chmod(target, os.FileMode(entry.Mode))
 				return nil
 			}()
 			if err != nil {
@@ -165,23 +169,36 @@ func Untar(tmpRoot string, tarFile string) error {
 				return err
 			}
 			linkname := entry.Linkname
-			var abs string
 			if strings.HasPrefix(linkname, "/") {
 				linkname = filepath.Join(tmpRoot, linkname)
-				abs = linkname
-			} else {
-				abs = filepath.Join(filepath.Dir(target), linkname)
+				linkname, err = filepath.Rel(filepath.Dir(target), linkname)
 			}
+			abs := filepath.Join(filepath.Dir(target), linkname)
 			if _, err := filepath.Rel(tmpRoot, abs); err != nil {
 				return err
 			}
 			if err = os.Symlink(linkname, target); err != nil {
 				return err
 			}
+		case tar.TypeLink:
+			dir := filepath.Dir(target)
+			err := os.MkdirAll(dir, os.ModePerm)
+			if err != nil {
+				return err
+			}
+			hardLinks[target] = entry.Linkname
 		default:
 			log.Debugf("Skipping %s with type %v", entry.Name, entry.Typeflag)
 		}
 	}
+
+	for target, source := range hardLinks {
+		source := filepath.Join(tmpRoot, source)
+		if err := os.Link(source, target); err != nil {
+			return fmt.Errorf("failed to create hard link from %s to %s", target, source)
+
+		}
+	}
 	return nil
 }