Proxy

url1, err := url.Parse("http://localhost:8081")
if err !=nil{
 e.Logger.Error("failed parse url","error", err)
}
url2, err := url.Parse("http://localhost:8082")
if err !=nil{
 e.Logger.Error("failed parse url","error", err)
}
e.Use(middleware.Proxy(middleware.NewRoundRobinBalancer([]*middleware.ProxyTarget{
{
 URL: url1,
},
{
 URL: url2,
},
})))

e := echo.New()
e.Use(middleware.ProxyWithConfig(middleware.ProxyConfig{}))

type ProxyConfig struct{
// Skipper defines a function to skip middleware.
	Skipper Skipper

// Balancer defines a load balancing technique.
// Required.
	Balancer ProxyBalancer

// RetryCount defines the number of times a failed proxied request should be retried
// using the next available ProxyTarget. Defaults to 0, meaning requests are never retried.
	RetryCount int

// RetryFilter defines a function used to determine if a failed request to a
// ProxyTarget should be retried. The RetryFilter will only be called when the number
// of previous retries is less than RetryCount. If the function returns true, the
// request will be retried. The provided error indicates the reason for the request
// failure. When the ProxyTarget is unavailable, the error will be an instance of
// echo.HTTPError with a code of http.StatusBadGateway. In all other cases, the error
// will indicate an internal error in the Proxy middleware. When a RetryFilter is not
// specified, all requests that fail with http.StatusBadGateway will be retried. A custom
// RetryFilter can be provided to only retry specific requests. Note that RetryFilter is
// only called when the request to the target fails, or an internal error in the Proxy
// middleware has occurred. Successful requests that return a non-200 response code cannot
// be retried.
	RetryFilter func(c *echo.Context, e error)bool

// ErrorHandler defines a function which can be used to return custom errors from
// the Proxy middleware. ErrorHandler is only invoked when there has been
// either an internal error in the Proxy middleware or the ProxyTarget is
// unavailable. Due to the way requests are proxied, ErrorHandler is not invoked
// when a ProxyTarget returns a non-200 response. In these cases, the response
// is already written so errors cannot be modified. ErrorHandler is only
// invoked after all retry attempts have been exhausted.
	ErrorHandler func(c *echo.Context, err error)error

// Rewrite defines URL path rewrite rules. The values captured in asterisk can be
// retrieved by index e.g. 1,ドル 2ドル and so on.
// Examples:
// "/old": "/new",
// "/api/*": "/1ドル",
// "/js/*": "/public/javascripts/1ドル",
// "/users/*/orders/*": "/user/1ドル/order/2ドル",
	Rewrite map[string]string

// RegexRewrite defines rewrite rules using regexp.Rexexp with captures
// Every capture group in the values can be retrieved by index e.g. 1,ドル 2ドル and so on.
// Example:
// "^/old/[0.9]+/": "/new",
// "^/api/.+?/(.*)": "/v2/1ドル",
	RegexRewrite map[*regexp.Regexp]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

// ModifyResponse defines function to modify response from ProxyTarget.
	ModifyResponse func(*http.Response)error
}

 e.Use(ProxyWithConfig(ProxyConfig{
 Balancer: rrb,
 Rewrite:map[string]string{
"^/v1/*":"/v2/1ドル",
},
 RegexRewrite:map[*regexp.Regexp]string{
 regexp.MustCompile("^/foo/([0-9].*)"):"/num/1ドル",
 regexp.MustCompile("^/bar/(.+?)/(.*)"):"/baz/2ドル/1ドル",
},
}))