Inspect: Add error if no results (#19476)

When no results match or another error occurs, add an error to the stream. Keep the "inspect-input.txt" as the only thing in the zip for reference.

Example:

```
λ mc support inspect --airgap myminio/testbucket/fjghfjh/**
mc: Using public key from C:\Users\klaus\mc\support_public.pem
File data successfully downloaded as inspect-data.enc

λ inspect inspect-data.enc
Using private key from support_private.pem
output written to inspect-data.zip
2024/04/11 14:10:51 next stream: GetRawData: No files matched the given pattern

λ unzip -l inspect-data.zip
Archive:  inspect-data.zip
  Length      Date    Time    Name
---------  ---------- -----   ----
      222  2024-04-11 14:10   inspect-input.txt
---------                     -------
      222                     1 file

λ
```

Modifies inspect to read until end of stream to report the error.

Bonus: Add legacy commandline params

docs/debugging/inspect/decrypt-v1.go

@@ -27,7 +27,7 @@ import (
 	"github.com/secure-io/sio-go"
 )
 
-func extractInspectV1(keyHex string, r io.Reader, w io.Writer) error {
+func extractInspectV1(keyHex string, r io.Reader, w io.Writer, okMsg string) error {
 	id, err := hex.DecodeString(keyHex[:8])
 	if err != nil {
 		return err
@@ -51,5 +51,8 @@ func extractInspectV1(keyHex string, r io.Reader, w io.Writer) error {
 	nonce := make([]byte, stream.NonceSize())
 	encr := stream.DecryptReader(r, nonce, nil)
 	_, err = io.Copy(w, encr)
+	if err == nil {
+		fmt.Println(okMsg)
+	}
 	return err
 }

docs/debugging/inspect/decrypt-v2.go

@@ -26,7 +26,11 @@ import (
 	"github.com/minio/madmin-go/v3/estream"
 )
 
-func extractInspectV2(pk []byte, r io.Reader, w io.Writer) error {
+type keepFileErr struct {
+	error
+}
+
+func extractInspectV2(pk []byte, r io.Reader, w io.Writer, okMsg string) error {
 	privKey, err := bytesToPrivateKey(pk)
 	if err != nil {
 		return fmt.Errorf("decoding key returned: %w", err)
@@ -45,11 +49,14 @@ func extractInspectV2(pk []byte, r io.Reader, w io.Writer) error {
 		sr.SkipEncrypted(true)
 		return sr.DebugStream(os.Stdout)
 	}
-
+	extracted := false
 	for {
 		stream, err := sr.NextStream()
 		if err != nil {
 			if err == io.EOF {
+				if extracted {
+					return nil
+				}
 				return errors.New("no data found on stream")
 			}
 			if errors.Is(err, estream.ErrNoKey) {
@@ -61,14 +68,22 @@ func extractInspectV2(pk []byte, r io.Reader, w io.Writer) error {
 				}
 				continue
 			}
+			if extracted {
+				return keepFileErr{fmt.Errorf("next stream: %w", err)}
+			}
 			return fmt.Errorf("next stream: %w", err)
 		}
 		if stream.Name == "inspect.zip" {
+			if extracted {
+				return keepFileErr{errors.New("multiple inspect.zip streams found")}
+			}
 			_, err := io.Copy(w, stream)
 			if err != nil {
 				return fmt.Errorf("reading inspect stream: %w", err)
 			}
-			return nil
+			fmt.Println(okMsg)
+			extracted = true
+			continue
 		}
 		if err := stream.Skip(); err != nil {
 			return fmt.Errorf("stream skip: %w", err)

docs/debugging/inspect/main.go

@@ -24,6 +24,7 @@ import (
 	"crypto/x509"
 	"encoding/json"
 	"encoding/pem"
+	"errors"
 	"flag"
 	"fmt"
 	"io"
@@ -117,18 +118,23 @@ func main() {
 	fatalErr(err)
 
 	// Decrypt the inspect data
+	msg := fmt.Sprintf("output written to %s", outputFileName)
+
 	switch {
 	case *keyHex != "":
-		err = extractInspectV1(*keyHex, input, output)
+		err = extractInspectV1(*keyHex, input, output, msg)
 	case len(privateKey) != 0:
-		err = extractInspectV2(privateKey, input, output)
+		err = extractInspectV2(privateKey, input, output, msg)
 	}
 	output.Close()
 	if err != nil {
-		os.Remove(outputFileName)
+
+		var keep keepFileErr
+		if !errors.As(err, &keep) {
+			os.Remove(outputFileName)
+		}
 		fatalErr(err)
 	}
-	fmt.Println("output written to", outputFileName)
 
 	// Export xl.meta to stdout
 	if *export {