echo-gcs-middleware

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This is a testing phase and not suitable for production use.

This Echo middleware provides a static file store powered by Google Cloud Storage as its backend. In detail, it facilitates the efficient delivery of static files—such as HTML, CSS, JavaScript, or image files—stored in Google Cloud Storage directly to end users. By leveraging this middleware, you can host static content on GCS without embedding these files directly within your application code, enabling seamless access to the content via HTTP requests.

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Usage

Installation

go get github.com/takumimas/echo-gcs-middleware

Example

func main() {
	ctx := context.Background()

	gcsClient, err := storage.NewClient(ctx)
	if err != nil {
		log.Fatalf("Failed to create GCS client: %v", err)
	}
	defer func() {
		if err := gcsClient.Close(); err != nil {
			log.Printf("Failed to close GCS client: %v", err)
		}
	}()

	e := echo.New()

	// Configure GCS middleware
	gcsConfig := gcsmiddleware.GCSStaticConfig{
		Client:     gcsClient,
		BucketName: "gcs-echo-test",
		IgnorePath: nil,  // Specify paths to ignore if any
		IsSPA:      true, // Set to true if serving a Single Page Application
		RootPath:   "/",   // Set the root path
		EnableCompression: true, // Enable gzip compression for text-based files
		CompressionLevel: 6, // Compression level (1-9, higher means better compression but slower)
		MinSizeForCompression: 1024, // Minimum file size in bytes for compression
	}

	// Create the GCS middleware
	gcsMiddleware := gcsmiddleware.NewGCSStaticMiddleware(gcsConfig)

	// Register the middleware with Echo
	e.Use(gcsMiddleware.ServerHeader)

	port := ":1323"
	log.Printf("Starting server on port %s...", port)
	if err := e.Start(port); err != nil {
		log.Fatalf("Failed to start the server: %v", err)
	}
}

Configuration Options

IsSPA

When IsSPA is set to true, any 404 errors will automatically redirect to index.html. This is useful for Single Page Applications (SPAs) where routing is handled client-side and all non-static paths should serve the main entry point (index.html).

RootPath

If you set RootPath to a specific value, such as /app/, it adjusts the base path from which files are served. For example, when RootPath is set to /app/, a request to /app/ will serve the file located at app/index.html.

Compression Settings

The middleware supports automatic compression of text-based files (HTML, CSS, JavaScript, etc.) to reduce transfer sizes and improve loading times. The following compression-related settings are available:

• EnableCompression: When set to true, enables automatic compression of compressible files.
• CompressionLevel: Specifies the compression level (1-9). Higher values provide better compression but are slower. Default is 6.
• MinSizeForCompression: The minimum file size in bytes required for compression to be applied. Files smaller than this size will be served uncompressed.

Currently supported compression formats:

• gzip (based on Accept-Encoding header)
• brotli (planned for future implementation)

Content-Length Header

The middleware automatically sets the Content-Length header for all responses, which helps browsers better handle the response and improve rendering performance. For compressed responses, the Content-Length reflects the size of the compressed data.