Merge pull request #1776 from aledbf/redirect-setting

Add option to configure the redirect code

docs/user-guide/configmap.md

@@ -112,6 +112,7 @@ The following table shows a configuration option's name, type, and the default v
 |[skip-access-log-urls](#skip-access-log-urls)|[]string|[]string{}|
 |[limit-rate](#limit-rate)|int|0|
 |[limit-rate-after](#limit-rate-after)|int|0|
+|[http-redirect-code](#http-redirect-code)|int|308|
 
 ## add-headers
 
@@ -635,3 +636,13 @@ Sets the initial amount after which the further transmission of a response to a
 
 _References:_
 - http://nginx.org/en/docs/http/ngx_http_core_module.html#limit_rate_after
+
+## http-redirect-code
+
+Sets the HTTP status code to be used in redirects.
+Supported codes are [301](https://developer.mozilla.org/es/docs/Web/HTTP/Status/301),[302](https://developer.mozilla.org/es/docs/Web/HTTP/Status/302),[307](https://developer.mozilla.org/es/docs/Web/HTTP/Status/307) and [308](https://developer.mozilla.org/es/docs/Web/HTTP/Status/308)
+Default code is 308.
+
+Why the default code is 308?
+
+[RFC 7238](https://tools.ietf.org/html/rfc7238) was created to define the 308 (Permanent Redirect) status code that is similar to 301 (Moved Permanently) but it keeps the payload in the redirect. This is important if the we send a redirect in methods like POST.

internal/ingress/controller/config/config.go

@@ -425,6 +425,11 @@ type Configuration struct {
 
 	// LocationSnippet adds custom configuration to all the locations in the nginx configuration
 	LocationSnippet string `json:"location-snippet"`
+
+	// HTTPRedirectCode sets the HTTP status code to be used in redirects.
+	// Supported codes are 301,302,307 and 308
+	// Default: 308
+	HTTPRedirectCode int `json:"http-redirect-code"`
 }
 
 // NewDefault returns the default nginx configuration
@@ -449,6 +454,7 @@ func NewDefault() Configuration {
 		ComputeFullForwardedFor:    false,
 		HTTP2MaxFieldSize:          "4k",
 		HTTP2MaxHeaderSize:         "16k",
+		HTTPRedirectCode:           308,
 		HSTS:                       true,
 		HSTSIncludeSubdomains:      true,
 		HSTSMaxAge:                 hstsMaxAge,

internal/ingress/controller/template/configmap.go

@@ -36,6 +36,11 @@ const (
 	whitelistSourceRange = "whitelist-source-range"
 	proxyRealIPCIDR      = "proxy-real-ip-cidr"
 	bindAddress          = "bind-address"
+	httpRedirectCode     = "http-redirect-code"
+)
+
+var (
+	validRedirectCodes = []int{301, 302, 307, 308}
 )
 
 // ReadConfig obtains the configuration defined by the user merged with the defaults.
@@ -52,6 +57,7 @@ func ReadConfig(src map[string]string) config.Configuration {
 	proxylist := make([]string, 0)
 	bindAddressIpv4List := make([]string, 0)
 	bindAddressIpv6List := make([]string, 0)
+	redirectCode := 308
 
 	if val, ok := conf[customHTTPErrors]; ok {
 		delete(conf, customHTTPErrors)
@@ -94,6 +100,20 @@ func ReadConfig(src map[string]string) config.Configuration {
 		}
 	}
 
+	if val, ok := conf[httpRedirectCode]; ok {
+		delete(conf, httpRedirectCode)
+		j, err := strconv.Atoi(val)
+		if err != nil {
+			glog.Warningf("%v is not a valid HTTP code: %v", val, err)
+		} else {
+			if intInSlice(j, validRedirectCodes) {
+				redirectCode = j
+			} else {
+				glog.Warningf("The code %v is not a valid as HTTP redirect code. Using the default.", val)
+			}
+		}
+	}
+
 	to := config.NewDefault()
 	to.CustomHTTPErrors = filterErrors(errors)
 	to.SkipAccessLogURLs = skipUrls
@@ -101,6 +121,7 @@ func ReadConfig(src map[string]string) config.Configuration {
 	to.ProxyRealIPCIDR = proxylist
 	to.BindAddressIpv4 = bindAddressIpv4List
 	to.BindAddressIpv6 = bindAddressIpv6List
+	to.HTTPRedirectCode = redirectCode
 
 	config := &mapstructure.DecoderConfig{
 		Metadata:         nil,
@@ -133,3 +154,12 @@ func filterErrors(codes []int) []int {
 
 	return fa
 }
+
+func intInSlice(i int, list []int) bool {
+	for _, v := range list {
+		if v == i {
+			return true
+		}
+	}
+	return false
+}

rootfs/etc/nginx/template/nginx.tmpl

@@ -390,9 +390,9 @@ http {
 
         {{ if ne $all.ListenPorts.HTTPS 443 }}
         {{ $redirect_port := (printf ":%v" $all.ListenPorts.HTTPS) }}
-        return 301 $scheme://{{ $to }}{{ $redirect_port }}$request_uri;
+        return {{ $all.Cfg.HTTPRedirectCode }} $scheme://{{ $to }}{{ $redirect_port }}$request_uri;
         {{ else }}
-        return 301 $scheme://{{ $to }}$request_uri;
+        return {{ $all.Cfg.HTTPRedirectCode }} $scheme://{{ $to }}$request_uri;
         {{ end }}
     }
     {{ end }}
@@ -687,9 +687,9 @@ stream {
             if ($pass_access_scheme = http) {
                 {{ if ne $all.ListenPorts.HTTPS 443 }}
                 {{ $redirect_port := (printf ":%v" $all.ListenPorts.HTTPS) }}
-                return 301 https://$best_http_host{{ $redirect_port }}$request_uri;
+                return {{ $all.Cfg.HTTPRedirectCode }} https://$best_http_host{{ $redirect_port }}$request_uri;
                 {{ else }}
-                return 301 https://$best_http_host$request_uri;
+                return {{ $all.Cfg.HTTPRedirectCode }} https://$best_http_host$request_uri;
                 {{ end }}
             }
             {{ end }}