Implement API response cache (#1645)

Apply peer validator cache mechanism

---------

Co-authored-by: Maycon Santos <mlsmaycon@gmail.com>
Co-authored-by: Yury Gargay <yury.gargay@gmail.com>
Co-authored-by: Viktor Liu <viktor@netbird.io>
Co-authored-by: Bethuel Mmbaga <bethuelmbaga12@gmail.com>
Co-authored-by: pascal-fischer <32096965+pascal-fischer@users.noreply.github.com>
Co-authored-by: Misha Bragin <bangvalo@gmail.com>

management/server/geolocation/utils.go

@@ -0,0 +1,176 @@
+package geolocation
+
+import (
+	"archive/tar"
+	"archive/zip"
+	"bufio"
+	"bytes"
+	"compress/gzip"
+	"crypto/sha256"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path"
+	"strings"
+)
+
+// decompressTarGzFile decompresses a .tar.gz file.
+func decompressTarGzFile(filepath, destDir string) error {
+	file, err := os.Open(filepath)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	gzipReader, err := gzip.NewReader(file)
+	if err != nil {
+		return err
+	}
+	defer gzipReader.Close()
+
+	tarReader := tar.NewReader(gzipReader)
+
+	for {
+		header, err := tarReader.Next()
+		if err != nil {
+			if errors.Is(err, io.EOF) {
+				break
+			}
+			return err
+		}
+
+		if header.Typeflag == tar.TypeReg {
+			outFile, err := os.Create(path.Join(destDir, path.Base(header.Name)))
+			if err != nil {
+				return err
+			}
+
+			_, err = io.Copy(outFile, tarReader) // #nosec G110
+			outFile.Close()
+			if err != nil {
+				return err
+			}
+		}
+
+	}
+
+	return nil
+}
+
+// decompressZipFile decompresses a .zip file.
+func decompressZipFile(filepath, destDir string) error {
+	r, err := zip.OpenReader(filepath)
+	if err != nil {
+		return err
+	}
+	defer r.Close()
+
+	for _, f := range r.File {
+		if f.FileInfo().IsDir() {
+			continue
+		}
+
+		outFile, err := os.Create(path.Join(destDir, path.Base(f.Name)))
+		if err != nil {
+			return err
+		}
+
+		rc, err := f.Open()
+		if err != nil {
+			outFile.Close()
+			return err
+		}
+
+		_, err = io.Copy(outFile, rc) // #nosec G110
+		outFile.Close()
+		rc.Close()
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// calculateFileSHA256 calculates the SHA256 checksum of a file.
+func calculateFileSHA256(filepath string) ([]byte, error) {
+	file, err := os.Open(filepath)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	h := sha256.New()
+	if _, err := io.Copy(h, file); err != nil {
+		return nil, err
+	}
+
+	return h.Sum(nil), nil
+}
+
+// loadChecksumFromFile loads the first checksum from a file.
+func loadChecksumFromFile(filepath string) (string, error) {
+	file, err := os.Open(filepath)
+	if err != nil {
+		return "", err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	if scanner.Scan() {
+		parts := strings.Fields(scanner.Text())
+		if len(parts) > 0 {
+			return parts[0], nil
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return "", err
+	}
+
+	return "", nil
+}
+
+// verifyChecksum compares the calculated SHA256 checksum of a file against the expected checksum.
+func verifyChecksum(filepath, expectedChecksum string) error {
+	calculatedChecksum, err := calculateFileSHA256(filepath)
+
+	fileCheckSum := fmt.Sprintf("%x", calculatedChecksum)
+	if err != nil {
+		return err
+	}
+
+	if fileCheckSum != expectedChecksum {
+		return fmt.Errorf("checksum mismatch: expected %s, got %s", expectedChecksum, fileCheckSum)
+	}
+
+	return nil
+}
+
+// downloadFile downloads a file from a URL and saves it to a local file path.
+func downloadFile(url, filepath string) error {
+	resp, err := http.Get(url)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	bodyBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("unexpected error occurred while downloading the file: %s", string(bodyBytes))
+	}
+
+	out, err := os.Create(filepath)
+	if err != nil {
+		return err
+	}
+	defer out.Close()
+
+	_, err = io.Copy(out, bytes.NewBuffer(bodyBytes))
+	return err
+}