Implemented rewrite middleware

Signed-off-by: Vishal Rana <vr@labstack.com>

middleware/body_dump.go

@@ -33,7 +33,7 @@ type (
 )
 
 var (
-	// DefaultBodyDumpConfig is the default Gzip middleware config.
+	// DefaultBodyDumpConfig is the default BodyDump middleware config.
 	DefaultBodyDumpConfig = BodyDumpConfig{
 		Skipper: DefaultSkipper,
 	}

middleware/body_limit.go

@@ -17,7 +17,7 @@ type (
 
 		// Maximum allowed size for a request body, it can be specified
 		// as `4x` or `4xB`, where x is one of the multiple from K, M, G, T or P.
-		Limit string `json:"limit"`
+		Limit string `yaml:"limit"`
 		limit int64
 	}
 

middleware/compress.go

@@ -20,7 +20,7 @@ type (
 
 		// Gzip compression level.
 		// Optional. Default value -1.
-		Level int `json:"level"`
+		Level int `yaml:"level"`
 	}
 
 	gzipResponseWriter struct {

middleware/cors.go

@@ -16,34 +16,34 @@ type (
 
 		// AllowOrigin defines a list of origins that may access the resource.
 		// Optional. Default value []string{"*"}.
-		AllowOrigins []string `json:"allow_origins"`
+		AllowOrigins []string `yaml:"allow_origins"`
 
 		// AllowMethods defines a list methods allowed when accessing the resource.
 		// This is used in response to a preflight request.
 		// Optional. Default value DefaultCORSConfig.AllowMethods.
-		AllowMethods []string `json:"allow_methods"`
+		AllowMethods []string `yaml:"allow_methods"`
 
 		// AllowHeaders defines a list of request headers that can be used when
 		// making the actual request. This in response to a preflight request.
 		// Optional. Default value []string{}.
-		AllowHeaders []string `json:"allow_headers"`
+		AllowHeaders []string `yaml:"allow_headers"`
 
 		// AllowCredentials indicates whether or not the response to the request
 		// can be exposed when the credentials flag is true. When used as part of
 		// a response to a preflight request, this indicates whether or not the
 		// actual request can be made using credentials.
 		// Optional. Default value false.
-		AllowCredentials bool `json:"allow_credentials"`
+		AllowCredentials bool `yaml:"allow_credentials"`
 
 		// ExposeHeaders defines a whitelist headers that clients are allowed to
 		// access.
 		// Optional. Default value []string{}.
-		ExposeHeaders []string `json:"expose_headers"`
+		ExposeHeaders []string `yaml:"expose_headers"`
 
 		// MaxAge indicates how long (in seconds) the results of a preflight request
 		// can be cached.
 		// Optional. Default value 0.
-		MaxAge int `json:"max_age"`
+		MaxAge int `yaml:"max_age"`
 	}
 )
 

middleware/csrf.go

@@ -18,7 +18,7 @@ type (
 		Skipper Skipper
 
 		// TokenLength is the length of the generated token.
-		TokenLength uint8 `json:"token_length"`
+		TokenLength uint8 `yaml:"token_length"`
 		// Optional. Default value 32.
 
 		// TokenLookup is a string in the form of "<source>:<key>" that is used
@@ -28,35 +28,35 @@ type (
 		// - "header:<name>"
 		// - "form:<name>"
 		// - "query:<name>"
-		TokenLookup string `json:"token_lookup"`
+		TokenLookup string `yaml:"token_lookup"`
 
 		// Context key to store generated CSRF token into context.
 		// Optional. Default value "csrf".
-		ContextKey string `json:"context_key"`
+		ContextKey string `yaml:"context_key"`
 
 		// Name of the CSRF cookie. This cookie will store CSRF token.
 		// Optional. Default value "csrf".
-		CookieName string `json:"cookie_name"`
+		CookieName string `yaml:"cookie_name"`
 
 		// Domain of the CSRF cookie.
 		// Optional. Default value none.
-		CookieDomain string `json:"cookie_domain"`
+		CookieDomain string `yaml:"cookie_domain"`
 
 		// Path of the CSRF cookie.
 		// Optional. Default value none.
-		CookiePath string `json:"cookie_path"`
+		CookiePath string `yaml:"cookie_path"`
 
 		// Max age (in seconds) of the CSRF cookie.
 		// Optional. Default value 86400 (24hr).
-		CookieMaxAge int `json:"cookie_max_age"`
+		CookieMaxAge int `yaml:"cookie_max_age"`
 
 		// Indicates if CSRF cookie is secure.
 		// Optional. Default value false.
-		CookieSecure bool `json:"cookie_secure"`
+		CookieSecure bool `yaml:"cookie_secure"`
 
 		// Indicates if CSRF cookie is HTTP only.
 		// Optional. Default value false.
-		CookieHTTPOnly bool `json:"cookie_http_only"`
+		CookieHTTPOnly bool `yaml:"cookie_http_only"`
 	}
 
 	// csrfTokenExtractor defines a function that takes `echo.Context` and returns

middleware/key_auth.go

@@ -21,7 +21,7 @@ type (
 		// - "header:<name>"
 		// - "query:<name>"
 		// - "form:<name>"
-		KeyLookup string `json:"key_lookup"`
+		KeyLookup string `yaml:"key_lookup"`
 
 		// AuthScheme to be used in the Authorization header.
 		// Optional. Default value "Bearer".

middleware/logger.go

@@ -46,7 +46,7 @@ type (
 		// Example "${remote_ip} ${status}"
 		//
 		// Optional. Default value DefaultLoggerConfig.Format.
-		Format string `json:"format"`
+		Format string `yaml:"format"`
 
 		// Output is a writer where logs in JSON format are written.
 		// Optional. Default value os.Stdout.

middleware/proxy_test.go

@@ -87,7 +87,7 @@ func TestProxy(t *testing.T) {
 
 	// Rewrite
 	e = echo.New()
-	e.Pre(ProxyWithConfig(ProxyConfig{
+	e.Use(ProxyWithConfig(ProxyConfig{
 		Balancer: rrb,
 		Rewrite: map[string]string{
 			"/old":              "/new",

middleware/recover.go

@@ -15,16 +15,16 @@ type (
 
 		// Size of the stack to be printed.
 		// Optional. Default value 4KB.
-		StackSize int `json:"stack_size"`
+		StackSize int `yaml:"stack_size"`
 
 		// DisableStackAll disables formatting stack traces of all other goroutines
 		// into buffer after the trace for the current goroutine.
 		// Optional. Default value false.
-		DisableStackAll bool `json:"disable_stack_all"`
+		DisableStackAll bool `yaml:"disable_stack_all"`
 
 		// DisablePrintStack disables printing stack trace.
 		// Optional. Default value as false.
-		DisablePrintStack bool `json:"disable_print_stack"`
+		DisablePrintStack bool `yaml:"disable_print_stack"`
 	}
 )
 

middleware/redirect.go

@@ -14,7 +14,7 @@ type (
 
 		// Status code to be used when redirecting the request.
 		// Optional. Default value http.StatusMovedPermanently.
-		Code int `json:"code"`
+		Code int `yaml:"code"`
 	}
 )
 

middleware/rewrite.go

@@ -0,0 +1,83 @@
+package middleware
+
+import (
+	"regexp"
+	"strings"
+
+	"github.com/labstack/echo"
+)
+
+type (
+	// RewriteConfig defines the config for Rewrite middleware.
+	RewriteConfig struct {
+		// Skipper defines a function to skip middleware.
+		Skipper Skipper
+
+		// Rules defines the URL path rewrite rules. The values captured in asterisk can be
+		// retrieved by index e.g. $1, $2 and so on.
+		// Examples:
+		// "/old":              "/new",
+		// "/api/*":            "/$1",
+		// "/js/*":             "/public/javascripts/$1",
+		// "/users/*/orders/*": "/user/$1/order/$2",
+		// Required.
+		Rules map[string]string `yaml:"rules"`
+
+		rulesRegex map[*regexp.Regexp]string
+	}
+)
+
+var (
+	// DefaultRewriteConfig is the default Rewrite middleware config.
+	DefaultRewriteConfig = RewriteConfig{
+		Skipper: DefaultSkipper,
+	}
+)
+
+// Rewrite returns a Rewrite middleware.
+//
+// Rewrite middleware rewrites the URL path based on the provided rules.
+func Rewrite(rules map[string]string) echo.MiddlewareFunc {
+	c := DefaultRewriteConfig
+	c.Rules = rules
+	return RewriteWithConfig(c)
+}
+
+// RewriteWithConfig returns a Rewrite middleware with config.
+// See: `Rewrite()`.
+func RewriteWithConfig(config RewriteConfig) echo.MiddlewareFunc {
+	// Defaults
+	if config.Rules == nil {
+		panic("echo: rewrite middleware requires url path rewrite rules")
+	}
+	if config.Skipper == nil {
+		config.Skipper = DefaultBodyDumpConfig.Skipper
+	}
+	config.rulesRegex = map[*regexp.Regexp]string{}
+
+	// Initialize
+	for k, v := range config.Rules {
+		k = strings.Replace(k, "*", "(\\S*)", -1)
+		config.rulesRegex[regexp.MustCompile(k)] = v
+	}
+
+	return func(next echo.HandlerFunc) echo.HandlerFunc {
+		return func(c echo.Context) (err error) {
+			if config.Skipper(c) {
+				return next(c)
+			}
+
+			req := c.Request()
+
+			// Rewrite
+			for k, v := range config.rulesRegex {
+				replacer := captureTokens(k, req.URL.Path)
+				if replacer != nil {
+					req.URL.Path = replacer.Replace(v)
+				}
+			}
+
+			return
+		}
+	}
+}

middleware/rewrite_test.go

@@ -0,0 +1,35 @@
+package middleware
+
+import (
+	"net/http/httptest"
+	"testing"
+
+	"github.com/labstack/echo"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRewrite(t *testing.T) {
+	e := echo.New()
+	e.Use(RewriteWithConfig(RewriteConfig{
+		Rules: map[string]string{
+			"/old":              "/new",
+			"/api/*":            "/$1",
+			"/js/*":             "/public/javascripts/$1",
+			"/users/*/orders/*": "/user/$1/order/$2",
+		},
+	}))
+	req := httptest.NewRequest(echo.GET, "/", nil)
+	rec := httptest.NewRecorder()
+	req.URL.Path = "/api/users"
+	e.ServeHTTP(rec, req)
+	assert.Equal(t, "/users", req.URL.Path)
+	req.URL.Path = "/js/main.js"
+	e.ServeHTTP(rec, req)
+	assert.Equal(t, "/public/javascripts/main.js", req.URL.Path)
+	req.URL.Path = "/old"
+	e.ServeHTTP(rec, req)
+	assert.Equal(t, "/new", req.URL.Path)
+	req.URL.Path = "/users/jack/orders/1"
+	e.ServeHTTP(rec, req)
+	assert.Equal(t, "/user/jack/order/1", req.URL.Path)
+}

middleware/secure.go

@@ -15,12 +15,12 @@ type (
 		// XSSProtection provides protection against cross-site scripting attack (XSS)
 		// by setting the `X-XSS-Protection` header.
 		// Optional. Default value "1; mode=block".
-		XSSProtection string `json:"xss_protection"`
+		XSSProtection string `yaml:"xss_protection"`
 
 		// ContentTypeNosniff provides protection against overriding Content-Type
 		// header by setting the `X-Content-Type-Options` header.
 		// Optional. Default value "nosniff".
-		ContentTypeNosniff string `json:"content_type_nosniff"`
+		ContentTypeNosniff string `yaml:"content_type_nosniff"`
 
 		// XFrameOptions can be used to indicate whether or not a browser should
 		// be allowed to render a page in a <frame>, <iframe> or <object> .
@@ -32,27 +32,27 @@ type (
 		// - "SAMEORIGIN" - The page can only be displayed in a frame on the same origin as the page itself.
 		// - "DENY" - The page cannot be displayed in a frame, regardless of the site attempting to do so.
 		// - "ALLOW-FROM uri" - The page can only be displayed in a frame on the specified origin.
-		XFrameOptions string `json:"x_frame_options"`
+		XFrameOptions string `yaml:"x_frame_options"`
 
 		// HSTSMaxAge sets the `Strict-Transport-Security` header to indicate how
 		// long (in seconds) browsers should remember that this site is only to
 		// be accessed using HTTPS. This reduces your exposure to some SSL-stripping
 		// man-in-the-middle (MITM) attacks.
 		// Optional. Default value 0.
-		HSTSMaxAge int `json:"hsts_max_age"`
+		HSTSMaxAge int `yaml:"hsts_max_age"`
 
 		// HSTSExcludeSubdomains won't include subdomains tag in the `Strict Transport Security`
 		// header, excluding all subdomains from security policy. It has no effect
 		// unless HSTSMaxAge is set to a non-zero value.
 		// Optional. Default value false.
-		HSTSExcludeSubdomains bool `json:"hsts_exclude_subdomains"`
+		HSTSExcludeSubdomains bool `yaml:"hsts_exclude_subdomains"`
 
 		// ContentSecurityPolicy sets the `Content-Security-Policy` header providing
 		// security against cross-site scripting (XSS), clickjacking and other code
 		// injection attacks resulting from execution of malicious content in the
 		// trusted web page context.
 		// Optional. Default value "".
-		ContentSecurityPolicy string `json:"content_security_policy"`
+		ContentSecurityPolicy string `yaml:"content_security_policy"`
 	}
 )
 

middleware/slash.go

@@ -12,7 +12,7 @@ type (
 
 		// Status code to be used when redirecting the request.
 		// Optional, but when provided the request is redirected using this code.
-		RedirectCode int `json:"redirect_code"`
+		RedirectCode int `yaml:"redirect_code"`
 	}
 )
 

middleware/static.go

@@ -19,20 +19,20 @@ type (
 
 		// Root directory from where the static content is served.
 		// Required.
-		Root string `json:"root"`
+		Root string `yaml:"root"`
 
 		// Index file for serving a directory.
 		// Optional. Default value "index.html".
-		Index string `json:"index"`
+		Index string `yaml:"index"`
 
 		// Enable HTML5 mode by forwarding all not-found requests to root so that
 		// SPA (single-page application) can handle the routing.
 		// Optional. Default value false.
-		HTML5 bool `json:"html5"`
+		HTML5 bool `yaml:"html5"`
 
 		// Enable directory browsing.
 		// Optional. Default value false.
-		Browse bool `json:"browse"`
+		Browse bool `yaml:"browse"`
 	}
 )