mirror of
https://github.com/labstack/echo.git
synced 2024-12-22 20:06:21 +02:00
6d9e043284
This reintroduces support for Go modules, as v4. CloseNotifier() is removed as it has been obsoleted, see https://golang.org/doc/go1.11#net/http It was already NOT working (not sending signals) as of 1.11 the functionality was gone, we merely deleted the functions that exposed it. If anyone still relies on it they should migrate to using `c.Request().Context().Done()` instead. Closes #1268, #1255
259 lines
6.3 KiB
Go
259 lines
6.3 KiB
Go
package middleware
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"math/rand"
|
|
"net"
|
|
"net/http"
|
|
"net/url"
|
|
"regexp"
|
|
"strings"
|
|
"sync"
|
|
"sync/atomic"
|
|
"time"
|
|
|
|
"github.com/labstack/echo/v4"
|
|
)
|
|
|
|
// TODO: Handle TLS proxy
|
|
|
|
type (
|
|
// ProxyConfig defines the config for Proxy middleware.
|
|
ProxyConfig struct {
|
|
// Skipper defines a function to skip middleware.
|
|
Skipper Skipper
|
|
|
|
// Balancer defines a load balancing technique.
|
|
// Required.
|
|
Balancer ProxyBalancer
|
|
|
|
// Rewrite defines 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",
|
|
Rewrite map[string]string
|
|
|
|
// Context key to store selected ProxyTarget into context.
|
|
// Optional. Default value "target".
|
|
ContextKey string
|
|
|
|
// To customize the transport to remote.
|
|
// Examples: If custom TLS certificates are required.
|
|
Transport http.RoundTripper
|
|
|
|
rewriteRegex map[*regexp.Regexp]string
|
|
}
|
|
|
|
// ProxyTarget defines the upstream target.
|
|
ProxyTarget struct {
|
|
Name string
|
|
URL *url.URL
|
|
Meta echo.Map
|
|
}
|
|
|
|
// ProxyBalancer defines an interface to implement a load balancing technique.
|
|
ProxyBalancer interface {
|
|
AddTarget(*ProxyTarget) bool
|
|
RemoveTarget(string) bool
|
|
Next(echo.Context) *ProxyTarget
|
|
}
|
|
|
|
commonBalancer struct {
|
|
targets []*ProxyTarget
|
|
mutex sync.RWMutex
|
|
}
|
|
|
|
// RandomBalancer implements a random load balancing technique.
|
|
randomBalancer struct {
|
|
*commonBalancer
|
|
random *rand.Rand
|
|
}
|
|
|
|
// RoundRobinBalancer implements a round-robin load balancing technique.
|
|
roundRobinBalancer struct {
|
|
*commonBalancer
|
|
i uint32
|
|
}
|
|
)
|
|
|
|
var (
|
|
// DefaultProxyConfig is the default Proxy middleware config.
|
|
DefaultProxyConfig = ProxyConfig{
|
|
Skipper: DefaultSkipper,
|
|
ContextKey: "target",
|
|
}
|
|
)
|
|
|
|
func proxyRaw(t *ProxyTarget, c echo.Context) http.Handler {
|
|
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
|
|
in, _, err := c.Response().Hijack()
|
|
if err != nil {
|
|
c.Error(fmt.Errorf("proxy raw, hijack error=%v, url=%s", t.URL, err))
|
|
return
|
|
}
|
|
defer in.Close()
|
|
|
|
out, err := net.Dial("tcp", t.URL.Host)
|
|
if err != nil {
|
|
he := echo.NewHTTPError(http.StatusBadGateway, fmt.Sprintf("proxy raw, dial error=%v, url=%s", t.URL, err))
|
|
c.Error(he)
|
|
return
|
|
}
|
|
defer out.Close()
|
|
|
|
// Write header
|
|
err = r.Write(out)
|
|
if err != nil {
|
|
he := echo.NewHTTPError(http.StatusBadGateway, fmt.Sprintf("proxy raw, request header copy error=%v, url=%s", t.URL, err))
|
|
c.Error(he)
|
|
return
|
|
}
|
|
|
|
errCh := make(chan error, 2)
|
|
cp := func(dst io.Writer, src io.Reader) {
|
|
_, err = io.Copy(dst, src)
|
|
errCh <- err
|
|
}
|
|
|
|
go cp(out, in)
|
|
go cp(in, out)
|
|
err = <-errCh
|
|
if err != nil && err != io.EOF {
|
|
c.Logger().Errorf("proxy raw, copy body error=%v, url=%s", t.URL, err)
|
|
}
|
|
})
|
|
}
|
|
|
|
// NewRandomBalancer returns a random proxy balancer.
|
|
func NewRandomBalancer(targets []*ProxyTarget) ProxyBalancer {
|
|
b := &randomBalancer{commonBalancer: new(commonBalancer)}
|
|
b.targets = targets
|
|
return b
|
|
}
|
|
|
|
// NewRoundRobinBalancer returns a round-robin proxy balancer.
|
|
func NewRoundRobinBalancer(targets []*ProxyTarget) ProxyBalancer {
|
|
b := &roundRobinBalancer{commonBalancer: new(commonBalancer)}
|
|
b.targets = targets
|
|
return b
|
|
}
|
|
|
|
// AddTarget adds an upstream target to the list.
|
|
func (b *commonBalancer) AddTarget(target *ProxyTarget) bool {
|
|
for _, t := range b.targets {
|
|
if t.Name == target.Name {
|
|
return false
|
|
}
|
|
}
|
|
b.mutex.Lock()
|
|
defer b.mutex.Unlock()
|
|
b.targets = append(b.targets, target)
|
|
return true
|
|
}
|
|
|
|
// RemoveTarget removes an upstream target from the list.
|
|
func (b *commonBalancer) RemoveTarget(name string) bool {
|
|
b.mutex.Lock()
|
|
defer b.mutex.Unlock()
|
|
for i, t := range b.targets {
|
|
if t.Name == name {
|
|
b.targets = append(b.targets[:i], b.targets[i+1:]...)
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
// Next randomly returns an upstream target.
|
|
func (b *randomBalancer) Next(c echo.Context) *ProxyTarget {
|
|
if b.random == nil {
|
|
b.random = rand.New(rand.NewSource(int64(time.Now().Nanosecond())))
|
|
}
|
|
b.mutex.RLock()
|
|
defer b.mutex.RUnlock()
|
|
return b.targets[b.random.Intn(len(b.targets))]
|
|
}
|
|
|
|
// Next returns an upstream target using round-robin technique.
|
|
func (b *roundRobinBalancer) Next(c echo.Context) *ProxyTarget {
|
|
b.i = b.i % uint32(len(b.targets))
|
|
t := b.targets[b.i]
|
|
atomic.AddUint32(&b.i, 1)
|
|
return t
|
|
}
|
|
|
|
// Proxy returns a Proxy middleware.
|
|
//
|
|
// Proxy middleware forwards the request to upstream server using a configured load balancing technique.
|
|
func Proxy(balancer ProxyBalancer) echo.MiddlewareFunc {
|
|
c := DefaultProxyConfig
|
|
c.Balancer = balancer
|
|
return ProxyWithConfig(c)
|
|
}
|
|
|
|
// ProxyWithConfig returns a Proxy middleware with config.
|
|
// See: `Proxy()`
|
|
func ProxyWithConfig(config ProxyConfig) echo.MiddlewareFunc {
|
|
// Defaults
|
|
if config.Skipper == nil {
|
|
config.Skipper = DefaultLoggerConfig.Skipper
|
|
}
|
|
if config.Balancer == nil {
|
|
panic("echo: proxy middleware requires balancer")
|
|
}
|
|
config.rewriteRegex = map[*regexp.Regexp]string{}
|
|
|
|
// Initialize
|
|
for k, v := range config.Rewrite {
|
|
k = strings.Replace(k, "*", "(\\S*)", -1)
|
|
config.rewriteRegex[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()
|
|
res := c.Response()
|
|
tgt := config.Balancer.Next(c)
|
|
c.Set(config.ContextKey, tgt)
|
|
|
|
// Rewrite
|
|
for k, v := range config.rewriteRegex {
|
|
replacer := captureTokens(k, req.URL.Path)
|
|
if replacer != nil {
|
|
req.URL.Path = replacer.Replace(v)
|
|
}
|
|
}
|
|
|
|
// Fix header
|
|
if req.Header.Get(echo.HeaderXRealIP) == "" {
|
|
req.Header.Set(echo.HeaderXRealIP, c.RealIP())
|
|
}
|
|
if req.Header.Get(echo.HeaderXForwardedProto) == "" {
|
|
req.Header.Set(echo.HeaderXForwardedProto, c.Scheme())
|
|
}
|
|
if c.IsWebSocket() && req.Header.Get(echo.HeaderXForwardedFor) == "" { // For HTTP, it is automatically set by Go HTTP reverse proxy.
|
|
req.Header.Set(echo.HeaderXForwardedFor, c.RealIP())
|
|
}
|
|
|
|
// Proxy
|
|
switch {
|
|
case c.IsWebSocket():
|
|
proxyRaw(tgt, c).ServeHTTP(res, req)
|
|
case req.Header.Get(echo.HeaderAccept) == "text/event-stream":
|
|
default:
|
|
proxyHTTP(tgt, c, config).ServeHTTP(res, req)
|
|
}
|
|
|
|
return
|
|
}
|
|
}
|
|
}
|