Add support to enable/disable proxy buffering (#1998)

* Enable proxy buffering using configmap and annotation

* add documentation

docs/user-guide/annotations.md

@@ -58,6 +58,7 @@ The following annotations are supported:
 |[nginx.ingress.kubernetes.io/upstream-hash-by](#custom-nginx-upstream-hashing)|string|
 |[nginx.ingress.kubernetes.io/upstream-vhost](#custom-nginx-upstream-vhost)|string|
 |[nginx.ingress.kubernetes.io/whitelist-source-range](#whitelist-source-range)|CIDR|
+|[nginx.ingress.kubernetes.io/proxy-buffering](#proxy-buffering)|string|
 
 **Note:** all the values must be a string. In case of booleans or number it must be quoted.
 
@@ -406,3 +407,15 @@ To use custom values in an Ingress rule define these annotation:
 ```yaml
 nginx.ingress.kubernetes.io/proxy-body-size: 8m
 ```
+
+### Proxy buffering
+
+Enable or disable proxy buffering [`proxy_buffering`](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_buffering).
+By default proxy buffering is disabled in the nginx config.
+
+To configure this setting globally for all Ingress rules, the `proxy-buffering` value may be set in the NGINX ConfigMap.
+To use custom values in an Ingress rule define these annotation:
+
+```yaml
+nginx.ingress.kubernetes.io/proxy-buffering: "on"
+```

docs/user-guide/configmap.md

@@ -126,6 +126,7 @@ The following table shows a configuration option's name, type, and the default v
 |[limit‑rate](#limit-rate)|int|0|
 |[limit‑rate‑after](#limit-rate-after)|int|0|
 |[http‑redirect‑code](#http-redirect-code)|int|308|
+|[proxy‑buffering](#proxy-buffering)|string|"off"|
 
 ## add-headers
 
@@ -698,3 +699,7 @@ 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.
+
+## proxy-buffering
+
+Enables or disables [buffering of responses from the proxied server](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_buffering).

internal/ingress/annotations/proxy/main.go

@@ -37,6 +37,7 @@ type Config struct {
 	ProxyRedirectFrom string `json:"proxyRedirectFrom"`
 	ProxyRedirectTo   string `json:"proxyRedirectTo"`
 	RequestBuffering  string `json:"requestBuffering"`
+	ProxyBuffering    string `json:"proxyBuffering"`
 }
 
 // Equal tests for equality between two Configuration types
@@ -83,6 +84,9 @@ func (l1 *Config) Equal(l2 *Config) bool {
 	if l1.ProxyRedirectTo != l2.ProxyRedirectTo {
 		return false
 	}
+	if l1.ProxyBuffering != l2.ProxyBuffering {
+		return false
+	}
 
 	return true
 }
@@ -99,6 +103,7 @@ func NewParser(r resolver.Resolver) parser.IngressAnnotation {
 // ParseAnnotations parses the annotations contained in the ingress
 // rule used to configure upstream check parameters
 func (a proxy) Parse(ing *extensions.Ingress) (interface{}, error) {
+
 	defBackend := a.r.GetDefaultBackend()
 	ct, err := parser.GetIntAnnotation("proxy-connect-timeout", ing)
 	if err != nil {
@@ -160,5 +165,10 @@ func (a proxy) Parse(ing *extensions.Ingress) (interface{}, error) {
 		prt = defBackend.ProxyRedirectTo
 	}
 
-	return &Config{bs, ct, st, rt, bufs, cd, cp, nu, pp, prf, prt, rb}, nil
+	pb, err := parser.GetStringAnnotation("proxy-buffering", ing)
+	if err != nil || pb == "" {
+		pb = defBackend.ProxyBuffering
+	}
+
+	return &Config{bs, ct, st, rt, bufs, cd, cp, nu, pp, prf, prt, rb, pb}, nil
 }

internal/ingress/annotations/proxy/main_test.go

@@ -79,6 +79,7 @@ func (m mockBackend) GetDefaultBackend() defaults.Backend {
 		ProxyNextUpstream:     "error",
 		ProxyPassParams:       "nocanon keepalive=On",
 		ProxyRequestBuffering: "on",
+		ProxyBuffering:        "off",
 	}
 }
 
@@ -94,6 +95,7 @@ func TestProxy(t *testing.T) {
 	data[parser.GetAnnotationWithPrefix("proxy-next-upstream")] = "off"
 	data[parser.GetAnnotationWithPrefix("proxy-pass-params")] = "smax=5 max=10"
 	data[parser.GetAnnotationWithPrefix("proxy-request-buffering")] = "off"
+	data[parser.GetAnnotationWithPrefix("proxy-buffering")] = "on"
 	ing.SetAnnotations(data)
 
 	i, err := NewParser(mockBackend{}).Parse(ing)
@@ -128,6 +130,9 @@ func TestProxy(t *testing.T) {
 	if p.RequestBuffering != "off" {
 		t.Errorf("expected off as request-buffering but returned %v", p.RequestBuffering)
 	}
+	if p.ProxyBuffering != "on" {
+		t.Errorf("expected on as proxy-buffering but returned %v", p.ProxyBuffering)
+	}
 }
 
 func TestProxyWithNoAnnotation(t *testing.T) {

internal/ingress/controller/config/config.go

@@ -548,6 +548,7 @@ func NewDefault() Configuration {
 			SkipAccessLogURLs:     []string{},
 			LimitRate:             0,
 			LimitRateAfter:        0,
+			ProxyBuffering:        "off",
 		},
 		UpstreamKeepaliveConnections: 32,
 		LimitConnZoneVariable:        defaultLimitConnZoneVariable,

internal/ingress/controller/controller.go

@@ -814,6 +814,7 @@ func (n *NGINXController) createServers(data []*extensions.Ingress,
 		NextUpstream:      bdef.ProxyNextUpstream,
 		RequestBuffering:  bdef.ProxyRequestBuffering,
 		ProxyRedirectFrom: bdef.ProxyRedirectFrom,
+		ProxyBuffering:    bdef.ProxyBuffering,
 	}
 
 	// generated on Start() with createDefaultSSLCertificate()

internal/ingress/defaults/main.go

@@ -138,4 +138,8 @@ type Backend struct {
 	// Sets the initial amount after which the further transmission of a response to a client will be rate limited.
 	// http://nginx.org/en/docs/http/ngx_http_core_module.html#limit_rate_after
 	LimitRateAfter int `json:"limit-rate-after"`
+
+	// Enables or disables buffering of responses from the proxied server.
+	// http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_buffering
+	ProxyBuffering string `json:"proxy-buffering"`
 }

rootfs/etc/nginx/template/nginx.tmpl

@@ -828,7 +828,7 @@ stream {
             proxy_send_timeout                      {{ $location.Proxy.SendTimeout }}s;
             proxy_read_timeout                      {{ $location.Proxy.ReadTimeout }}s;
 
-            proxy_buffering                         off;
+            proxy_buffering                         "{{ $location.Proxy.ProxyBuffering }}";
             proxy_buffer_size                       "{{ $location.Proxy.BufferSize }}";
             proxy_buffers                           4 "{{ $location.Proxy.BufferSize }}";
             proxy_request_buffering                 "{{ $location.Proxy.RequestBuffering }}";