Initial abstract implementation of middlewares

.github/workflows/docker-image.yml

@@ -1,7 +1,8 @@
 name: Docker Image CI
 
 on:
-    push: {}
+    push:
+        tags: ["*"]
 
 env:
     REGISTRY: ghcr.io

src/autocert/config.go

@@ -32,13 +32,13 @@ func (cfg *Config) GetProvider() (provider *Provider, res E.NestedError) {
 
 	if cfg.Provider != ProviderLocal {
 		if len(cfg.Domains) == 0 {
-			b.Addf("no domains specified")
+			b.Addf("%s", "no domains specified")
 		}
 		if cfg.Provider == "" {
-			b.Addf("no provider specified")
+			b.Addf("%s", "no provider specified")
 		}
 		if cfg.Email == "" {
-			b.Addf("no email specified")
+			b.Addf("%s", "no email specified")
 		}
 		// check if provider is implemented
 		_, ok := providersGenMap[cfg.Provider]

src/common/env.go

@@ -1,8 +1,10 @@
 package common
 
 import (
+	"net"
 	"os"
 
+	"github.com/sirupsen/logrus"
 	U "github.com/yusing/go-proxy/utils"
 )
 
@@ -12,6 +14,10 @@ var (
 	ProxyHTTPAddr      = GetEnv("GOPROXY_HTTP_ADDR", ":80")
 	ProxyHTTPSAddr     = GetEnv("GOPROXY_HTTPS_ADDR", ":443")
 	APIHTTPAddr        = GetEnv("GOPROXY_API_ADDR", "127.0.0.1:8888")
+
+	ProxyHTTPPort  = getPort(ProxyHTTPAddr)
+	ProxyHTTPSPort = getPort(ProxyHTTPSAddr)
+	ProxyAPIPort   = getPort(APIHTTPAddr)
 )
 
 func GetEnvBool(key string) bool {
@@ -25,3 +31,11 @@ func GetEnv(key string, defaultValue string) string {
 	}
 	return value
 }
+
+func getPort(addr string) string {
+	_, port, err := net.SplitHostPort(addr)
+	if err != nil {
+		logrus.Fatalf("Invalid address: %s", addr)
+	}
+	return port
+}

src/error/error.go

@@ -118,9 +118,9 @@ func (ne NestedError) With(s any) NestedError {
 	case string:
 		msg = ss
 	case fmt.Stringer:
-		return ne.append(ss.String())
+		return ne.appendMsg(ss.String())
 	default:
-		return ne.append(fmt.Sprint(s))
+		return ne.appendMsg(fmt.Sprint(s))
 	}
 	return ne.withError(From(errors.New(msg)))
 }
@@ -207,7 +207,7 @@ func (ne NestedError) withError(err NestedError) NestedError {
 	return ne
 }
 
-func (ne NestedError) append(msg string) NestedError {
+func (ne NestedError) appendMsg(msg string) NestedError {
 	if ne == nil {
 		return nil
 	}

src/proxy/reverse_proxy_mod.go

@@ -143,6 +143,8 @@ type ReverseProxy struct {
 	// If nil, the default is to log the provided error and return
 	// a 502 Status Bad Gateway response.
 	ErrorHandler func(http.ResponseWriter, *http.Request, error)
+
+	ServeHTTP http.HandlerFunc
 }
 
 // A BufferPool is an interface for getting and returning temporary
@@ -230,12 +232,16 @@ func NewReverseProxy(target *url.URL, transport http.RoundTripper, entry *Revers
 			}
 		}
 	}
-	return &ReverseProxy{Rewrite: func(pr *ProxyRequest) {
-		rewriteRequestURL(pr.Out, target)
-		// pr.SetXForwarded()
-		setHeaders(pr.Out)
-		hideHeaders(pr.Out)
-	}, Transport: transport}
+	rp := &ReverseProxy{
+		Rewrite: func(pr *ProxyRequest) {
+			rewriteRequestURL(pr.Out, target)
+			// pr.SetXForwarded()
+			setHeaders(pr.Out)
+			hideHeaders(pr.Out)
+		}, Transport: transport,
+	}
+	rp.ServeHTTP = rp.serveHTTP
+	return rp
 }
 
 func rewriteRequestURL(req *http.Request, target *url.URL) {
@@ -277,7 +283,7 @@ func (p *ReverseProxy) modifyResponse(rw http.ResponseWriter, res *http.Response
 	return true
 }
 
-func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+func (p *ReverseProxy) serveHTTP(rw http.ResponseWriter, req *http.Request) {
 	transport := p.Transport
 
 	ctx := req.Context()
@@ -348,9 +354,9 @@ func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	}
 
 	outreq.Header.Del("Forwarded")
-	outreq.Header.Del("X-Forwarded-For")
-	outreq.Header.Del("X-Forwarded-Host")
-	outreq.Header.Del("X-Forwarded-Proto")
+	// outreq.Header.Del("X-Forwarded-For")
+	// outreq.Header.Del("X-Forwarded-Host")
+	// outreq.Header.Del("X-Forwarded-Proto")
 
 	pr := &ProxyRequest{
 		In:  req,

src/route/middleware/add_x_forwarded.go

@@ -0,0 +1,7 @@
+package middleware
+
+var AddXForwarded = &Middleware{
+	rewrite: func(r *ProxyRequest) {
+		r.SetXForwarded()
+	},
+}

src/route/middleware/middleware.go

@@ -0,0 +1,135 @@
+package middleware
+
+import (
+	"net/http"
+
+	E "github.com/yusing/go-proxy/error"
+	P "github.com/yusing/go-proxy/proxy"
+)
+
+type (
+	ReverseProxy   = P.ReverseProxy
+	ProxyRequest   = P.ProxyRequest
+	Request        = http.Request
+	Response       = http.Response
+	ResponseWriter = http.ResponseWriter
+
+	BeforeFunc         func(w ResponseWriter, r *Request) (continue_ bool)
+	RewriteFunc        func(req *ProxyRequest)
+	ModifyResponseFunc func(res *Response) error
+
+	MiddlewareOptionsRaw map[string]string
+	MiddlewareOptions    map[string]interface{}
+
+	Middleware struct {
+		name string
+
+		before         BeforeFunc
+		rewrite        RewriteFunc
+		modifyResponse ModifyResponseFunc
+
+		options         MiddlewareOptions
+		validateOptions func(opts MiddlewareOptionsRaw) (MiddlewareOptions, E.NestedError)
+	}
+)
+
+func (m *Middleware) Name() string {
+	return m.name
+}
+
+func (m *Middleware) String() string {
+	return m.name
+}
+
+func (m *Middleware) WithOptions(optsRaw MiddlewareOptionsRaw) (*Middleware, E.NestedError) {
+	if len(optsRaw) == 0 {
+		return m, nil
+	}
+
+	var opts MiddlewareOptions
+	var err E.NestedError
+
+	if m.validateOptions != nil {
+		if opts, err = m.validateOptions(optsRaw); err != nil {
+			return nil, err
+		}
+	}
+
+	return &Middleware{
+		name:           m.name,
+		before:         m.before,
+		rewrite:        m.rewrite,
+		modifyResponse: m.modifyResponse,
+		options:        opts,
+	}, nil
+}
+
+// TODO: check conflict
+func PatchReverseProxy(rp ReverseProxy, middlewares map[string]MiddlewareOptionsRaw) (out ReverseProxy, err E.NestedError) {
+	out = rp
+
+	befores := make([]BeforeFunc, 0, len(middlewares))
+	rewrites := make([]RewriteFunc, 0, len(middlewares))
+	modifyResponses := make([]ModifyResponseFunc, 0, len(middlewares))
+
+	invalidM := E.NewBuilder("invalid middlewares")
+	invalidOpts := E.NewBuilder("invalid options")
+	defer invalidM.Add(invalidOpts.Build())
+	defer invalidM.To(&err)
+
+	for name, opts := range middlewares {
+		m, ok := Get(name)
+		if !ok {
+			invalidM.Addf("%s", name)
+			continue
+		}
+		m, err = m.WithOptions(opts)
+		if err != nil {
+			invalidOpts.Add(err.Subject(name))
+			continue
+		}
+		if m.before != nil {
+			befores = append(befores, m.before)
+		}
+		if m.rewrite != nil {
+			rewrites = append(rewrites, m.rewrite)
+		}
+		if m.modifyResponse != nil {
+			modifyResponses = append(modifyResponses, m.modifyResponse)
+		}
+	}
+
+	if invalidM.HasError() {
+		return
+	}
+
+	if len(befores) > 0 {
+		rp.ServeHTTP = func(w ResponseWriter, r *Request) {
+			for _, before := range befores {
+				if !before(w, r) {
+					return
+				}
+			}
+			rp.ServeHTTP(w, r)
+		}
+	}
+	if len(rewrites) > 0 {
+		rp.Rewrite = func(req *ProxyRequest) {
+			for _, rewrite := range rewrites {
+				rewrite(req)
+			}
+		}
+	}
+	if len(modifyResponses) > 0 {
+		rp.ModifyResponse = func(res *Response) error {
+			for _, modifyResponse := range modifyResponses {
+				if err := modifyResponse(res); err != nil {
+					return err
+				}
+			}
+			return nil
+		}
+	}
+
+	return
+}

src/route/middleware/middlewares.go

@@ -0,0 +1,34 @@
+package middleware
+
+import (
+	"fmt"
+	"strings"
+)
+
+var middlewares = map[string]*Middleware{
+	"set_x_forwarded":      SetXForwarded, // nginx
+	"add_x_forwarded":      AddXForwarded, // nginx
+	"trust_forward_header": AddXForwarded, // traefik alias
+	"redirect_http":        RedirectHTTP,
+}
+
+func Get(name string) (middleware *Middleware, ok bool) {
+	middleware, ok = middlewares[name]
+	return
+}
+
+// initialize middleware names
+var _ = func() (_ bool) {
+	names := make(map[*Middleware][]string)
+	for name, m := range middlewares {
+		names[m] = append(names[m], name)
+	}
+	for m, names := range names {
+		if len(names) > 1 {
+			m.name = fmt.Sprintf("%s (a.k.a. %s)", names[0], strings.Join(names[1:], ", "))
+		} else {
+			m.name = names[0]
+		}
+	}
+	return
+}()

src/route/middleware/redirect_http.go

@@ -0,0 +1,20 @@
+package middleware
+
+import (
+	"net/http"
+
+	"github.com/yusing/go-proxy/common"
+)
+
+var RedirectHTTP = &Middleware{
+	before: func(w ResponseWriter, r *Request) (continue_ bool) {
+		if r.TLS == nil {
+			r.URL.Scheme = "https"
+			r.URL.Host = r.URL.Hostname() + common.ProxyHTTPSPort
+			http.Redirect(w, r, r.URL.String(), http.StatusTemporaryRedirect)
+		} else {
+			continue_ = true
+		}
+		return
+	},
+}

src/route/middleware/set_x_forwarded.go

@@ -0,0 +1,10 @@
+package middleware
+
+var SetXForwarded = &Middleware{
+	rewrite: func(r *ProxyRequest) {
+		r.Out.Header.Del("X-Forwarded-For")
+		r.Out.Header.Del("X-Forwarded-Host")
+		r.Out.Header.Del("X-Forwarded-Proto")
+		r.SetXForwarded()
+	},
+}