first commit

framework/plugins/utils.go

@@ -0,0 +1,111 @@
+package plugins
+
+import (
+	"fmt"
+	"net/url"
+	"os"
+	"time"
+
+	"github.com/valyala/fasthttp"
+)
+
+var (
+	ErrPluginNotFound = fmt.Errorf("plugin not found")
+)
+
+// pluginDownloadClient is a fasthttp client with a larger read buffer to handle
+// responses with large headers.
+var pluginDownloadClient = &fasthttp.Client{
+	ReadBufferSize: 64 * 1024, // 64KB, matches the bifrost HTTP server setting
+}
+
+// DownloadPlugin downloads a plugin from a URL and returns the local file path
+func DownloadPlugin(pluginURL string, extension string) (string, error) {
+	req := fasthttp.AcquireRequest()
+	defer fasthttp.ReleaseRequest(req)
+	response := fasthttp.AcquireResponse()
+	defer fasthttp.ReleaseResponse(response)
+
+	req.Header.SetMethod(fasthttp.MethodGet)
+	req.Header.Set("Accept", "application/octet-stream")
+	req.Header.Set("Accept-Encoding", "gzip")
+	req.Header.Set("Accept-Language", "en-US,en;q=0.9")
+
+	const maxRedirects = 5
+	currentURL := pluginURL
+	for i := 0; i <= maxRedirects; i++ {
+		req.SetRequestURI(currentURL)
+		if i > 0 {
+			response.Reset()
+		}
+
+		if err := pluginDownloadClient.DoTimeout(req, response, 120*time.Second); err != nil {
+			return "", err
+		}
+
+		statusCode := response.StatusCode()
+		if statusCode == fasthttp.StatusOK {
+			break
+		}
+		if statusCode >= 300 && statusCode < 400 {
+			if i == maxRedirects {
+				return "", fmt.Errorf("too many redirects downloading plugin")
+			}
+			location := string(response.Header.Peek("Location"))
+			if location == "" {
+				return "", fmt.Errorf("redirect response missing Location header: HTTP %d", statusCode)
+			}
+			loc, err := url.Parse(location)
+			if err != nil {
+				return "", fmt.Errorf("invalid Location header %q: %w", location, err)
+			}
+			base, err := url.Parse(currentURL)
+			if err != nil {
+				return "", fmt.Errorf("invalid request URL %q: %w", currentURL, err)
+			}
+			currentURL = base.ResolveReference(loc).String()
+			continue
+		}
+		return "", fmt.Errorf("failed to download plugin: HTTP %d", statusCode)
+	}
+
+	// Decompress the response body if it was gzip/deflate compressed
+	// BodyUncompressed handles both gzip and deflate encodings based on Content-Encoding header
+	body, err := response.BodyUncompressed()
+	if err != nil {
+		return "", fmt.Errorf("failed to decompress response body: %w", err)
+	}
+
+	// Create a unique temporary file for the plugin
+	tempFile, err := os.CreateTemp(os.TempDir(), "bifrost-plugin-*"+extension)
+	if err != nil {
+		return "", fmt.Errorf("failed to create temporary file: %w", err)
+	}
+	tempPath := tempFile.Name()
+
+	// Write the downloaded body to the temporary file
+	_, err = tempFile.Write(body)
+	if err != nil {
+		tempFile.Close()
+		os.Remove(tempPath)
+		return "", fmt.Errorf("failed to write plugin to temporary file: %w", err)
+	}
+
+	// Close the file
+	err = tempFile.Close()
+	if err != nil {
+		os.Remove(tempPath)
+		return "", fmt.Errorf("failed to close temporary file: %w", err)
+	}
+
+	// Set file permissions to be executable (for .so files)
+	if extension == ".so" {
+		err = os.Chmod(tempPath, 0755)
+		if err != nil {
+			os.Remove(tempPath)
+			return "", fmt.Errorf("failed to set executable permissions on plugin: %w", err)
+		}
+	}
+
+	return tempPath, nil
+}