overhaul ghw-snapshot tool

cmd/ghw-snapshot/command/create.go

@@ -0,0 +1,85 @@
+//
+// Use and distribution licensed under the Apache license version 2.
+//
+// See the COPYING file in the root project directory for full text.
+//
+
+package command
+
+import (
+	"crypto/md5"
+	"fmt"
+	"io"
+	"os"
+	"runtime"
+
+	"github.com/spf13/cobra"
+
+	"github.com/jaypipes/ghw/pkg/snapshot"
+)
+
+var (
+	// output filepath to save snapshot to
+	outPath string
+)
+
+var createCmd = &cobra.Command{
+	Use:   "create",
+	Short: "Creates a new ghw snapshot",
+	RunE:  doCreate,
+}
+
+// doCreate creates a ghw snapshot
+func doCreate(cmd *cobra.Command, args []string) error {
+	scratchDir, err := os.MkdirTemp("", "ghw-snapshot")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(scratchDir)
+
+	snapshot.SetTraceFunction(trace)
+	if err = snapshot.CloneTreeInto(scratchDir); err != nil {
+		return err
+	}
+
+	if outPath == "" {
+		outPath, err = defaultOutPath()
+		if err != nil {
+			return err
+		}
+		trace("using default output filepath %s\n", outPath)
+	}
+
+	return snapshot.PackFrom(outPath, scratchDir)
+}
+
+func systemFingerprint() (string, error) {
+	hn, err := os.Hostname()
+	if err != nil {
+		return "unknown", err
+	}
+	m := md5.New()
+	_, err = io.WriteString(m, hn)
+	if err != nil {
+		return "unknown", err
+	}
+	return fmt.Sprintf("%x", m.Sum(nil)), nil
+}
+
+func defaultOutPath() (string, error) {
+	fp, err := systemFingerprint()
+	if err != nil {
+		return "unknown", err
+	}
+	return fmt.Sprintf("%s-%s-%s.tar.gz", runtime.GOOS, runtime.GOARCH, fp), nil
+}
+
+func init() {
+	createCmd.PersistentFlags().StringVarP(
+		&outPath,
+		"out", "o",
+		outPath,
+		"Path to place snapshot. Defaults to file in current directory with name $OS-$ARCH-$HASHSYSTEMNAME.tar.gz",
+	)
+	rootCmd.AddCommand(createCmd)
+}

cmd/ghw-snapshot/command/read.go

@@ -0,0 +1,47 @@
+//
+// Use and distribution licensed under the Apache license version 2.
+//
+// See the COPYING file in the root project directory for full text.
+//
+
+package command
+
+import (
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"github.com/jaypipes/ghw"
+	ghwcontext "github.com/jaypipes/ghw/pkg/context"
+)
+
+var readCmd = &cobra.Command{
+	Use:   "read",
+	Short: "Reads a new ghw snapshot",
+	RunE:  doRead,
+}
+
+// doRead reads a ghw snapshot from the input snapshot path argument
+func doRead(cmd *cobra.Command, args []string) error {
+	if len(args) != 1 {
+		return errors.New("supply a single argument with the filepath to the snapshot you wish to read")
+	}
+	inPath := args[0]
+	if _, err := os.Stat(inPath); err != nil {
+		return err
+	}
+	os.Setenv("GHW_SNAPSHOT_PATH", inPath)
+	ctx := ghwcontext.New()
+
+	return ctx.Do(func() error {
+		info, err := ghw.Host()
+		fmt.Println(info.String())
+		return err
+	})
+}
+
+func init() {
+	rootCmd.AddCommand(readCmd)
+}

cmd/ghw-snapshot/command/root.go

@@ -0,0 +1,59 @@
+//
+// Use and distribution licensed under the Apache license version 2.
+//
+// See the COPYING file in the root project directory for full text.
+//
+
+package command
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+var (
+	debug bool
+)
+
+// rootCmd represents the base command when called without any subcommands
+var rootCmd = &cobra.Command{
+	Use:   "ghw-snapshot",
+	Short: "ghw-snapshot - create and read ghw snapshots.",
+	Long: `
+        __                                                   __           __   
+.-----.|  |--.--.--.--.______.-----.-----.---.-.-----.-----.|  |--.-----.|  |_ 
+|  _  ||     |  |  |  |______|__ --|     |  _  |  _  |__ --||     |  _  ||   _|
+|___  ||__|__|________|      |_____|__|__|___._|   __|_____||__|__|_____||____|
+|_____|                                        |__|                            
+
+Create and read ghw snapshots.
+
+https://github.com/jaypipes/ghw
+`,
+	RunE: doCreate,
+}
+
+// Execute adds all child commands to the root command and sets flags
+// appropriately. This is called by main.main(). It only needs to happen once
+// to the rootCmd.
+func Execute() {
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
+
+func trace(msg string, args ...interface{}) {
+	if !debug {
+		return
+	}
+	fmt.Printf(msg, args...)
+}
+
+func init() {
+	rootCmd.PersistentFlags().BoolVar(
+		&debug, "debug", false, "Enable or disable debug mode",
+	)
+}

cmd/ghw-snapshot/main.go

@@ -1,105 +1,16 @@
 //go:build linux
 // +build linux
 
-//
 // Use and distribution licensed under the Apache license version 2.
 //
 // See the COPYING file in the root project directory for full text.
-//
 
 package main
 
 import (
-	"crypto/md5"
-	"fmt"
-	"io"
-	"os"
-	"runtime"
-
-	"github.com/spf13/cobra"
-
-	"github.com/jaypipes/ghw/pkg/snapshot"
-)
-
-var (
-	// show debug output
-	debug = false
-	// output filepath to save snapshot to
-	outPath string
+	"github.com/jaypipes/ghw/cmd/ghw-snapshot/command"
 )
 
-// rootCmd represents the base command when called without any subcommands
-var rootCmd = &cobra.Command{
-	Use:   "ghw-snapshot",
-	Short: "ghw-snapshot - Snapshot filesystem containing system information.",
-	RunE:  execute,
-}
-
-func trace(msg string, args ...interface{}) {
-	if !debug {
-		return
-	}
-	fmt.Printf(msg, args...)
-}
-
-func systemFingerprint() (string, error) {
-	hn, err := os.Hostname()
-	if err != nil {
-		return "unknown", err
-	}
-	m := md5.New()
-	_, err = io.WriteString(m, hn)
-	if err != nil {
-		return "unknown", err
-	}
-	return fmt.Sprintf("%x", m.Sum(nil)), nil
-}
-
-func defaultOutPath() (string, error) {
-	fp, err := systemFingerprint()
-	if err != nil {
-		return "unknown", err
-	}
-	return fmt.Sprintf("%s-%s-%s.tar.gz", runtime.GOOS, runtime.GOARCH, fp), nil
-}
-
-func execute(cmd *cobra.Command, args []string) error {
-	scratchDir, err := os.MkdirTemp("", "ghw-snapshot")
-	if err != nil {
-		return err
-	}
-	defer os.RemoveAll(scratchDir)
-
-	snapshot.SetTraceFunction(trace)
-	if err = snapshot.CloneTreeInto(scratchDir); err != nil {
-		return err
-	}
-
-	if outPath == "" {
-		outPath, err = defaultOutPath()
-		if err != nil {
-			return err
-		}
-		trace("using default output filepath %s\n", outPath)
-	}
-
-	return snapshot.PackFrom(outPath, scratchDir)
-}
-
 func main() {
-	if err := rootCmd.Execute(); err != nil {
-		trace("execution failed: %v\n", err)
-	}
-}
-
-func init() {
-	rootCmd.PersistentFlags().StringVarP(
-		&outPath,
-		"out", "o",
-		outPath,
-		"Path to place snapshot. Defaults to file in current directory with name $OS-$ARCH-$HASHSYSTEMNAME.tar.gz",
-	)
-	rootCmd.PersistentFlags().BoolVarP(
-		&debug, "debug", "d", false, "Enable or disable debug mode",
-	)
+	command.Execute()
 }