Merge pull request #907 from glerchundi/master

nginx/proxy: allow specifying next upstream behaviour

controllers/nginx/configuration.md

@@ -349,6 +349,9 @@ log-format-upstream: '{ "time": "$time_iso8601", "remote_addr": "$proxy_protocol
 **proxy-send-timeout:** Sets the timeout in seconds for [transmitting a request to the proxied server](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_send_timeout). The timeout is set only between two successive write operations, not for the transmission of the whole request.
 
 
+**proxy-next-upstream:** Specifies in [which cases](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_next_upstream) a request should be passed to the next server.
+
+
 **retry-non-idempotent:** Since 1.9.13 NGINX will not retry non-idempotent requests (POST, LOCK, PATCH) in case of an error in the upstream server.
 
 The previous behavior can be restored using the value "true".

controllers/nginx/pkg/config/config.go

@@ -354,6 +354,7 @@ func NewDefault() Configuration {
 			ProxyBufferSize:      "4k",
 			ProxyCookieDomain:    "off",
 			ProxyCookiePath:      "off",
+			ProxyNextUpstream:    "error timeout invalid_header http_502 http_503 http_504",
 			SSLRedirect:          true,
 			CustomHTTPErrors:     []int{},
 			WhitelistSourceRange: []string{},

controllers/nginx/pkg/template/template.go

@@ -146,6 +146,7 @@ var (
 		"toUpper":                  strings.ToUpper,
 		"toLower":                  strings.ToLower,
 		"formatIP":                 formatIP,
+		"buildNextUpstream":        buildNextUpstream,
 	}
 )
 
@@ -450,3 +451,21 @@ func isSticky(host string, loc *ingress.Location, stickyLocations map[string][]s
 
 	return false
 }
+
+func buildNextUpstream(input interface{}) string {
+	nextUpstream, ok := input.(string)
+	if !ok {
+		glog.Errorf("expected an string type but %T was returned", input)
+	}
+
+	parts := strings.Split(nextUpstream, " ")
+
+	nextUpstreamCodes := make([]string, 0, len(parts))
+	for _, v := range parts {
+		if v != "" && v != "non_idempotent" {
+			nextUpstreamCodes = append(nextUpstreamCodes, v)
+		}
+	}
+
+	return strings.Join(nextUpstreamCodes, " ")
+}

controllers/nginx/rootfs/etc/nginx/template/nginx.tmpl

@@ -221,9 +221,6 @@ http {
     {{ range $errCode := $cfg.CustomHTTPErrors }}
     error_page {{ $errCode }} = @custom_{{ $errCode }};{{ end }}
 
-    # In case of errors try the next upstream server before returning an error
-    proxy_next_upstream                     error timeout invalid_header http_502 http_503 http_504{{ if $cfg.RetryNonIdempotent }} non_idempotent{{ end }};
-
     proxy_ssl_session_reuse on;
 
     {{ if $cfg.AllowBackendServerHeader }}
@@ -444,6 +441,9 @@ http {
             proxy_cookie_domain                     {{ $location.Proxy.CookieDomain }};
             proxy_cookie_path                       {{ $location.Proxy.CookiePath }};
 
+            # In case of errors try the next upstream server before returning an error
+            proxy_next_upstream                     {{ buildNextUpstream $location.Proxy.NextUpstream }}{{ if $cfg.RetryNonIdempotent }} non_idempotent{{ end }};
+
             {{/* rewrite only works if the content is not compressed */}}
             {{ if $location.Redirect.AddBaseURL }}
             proxy_set_header                        Accept-Encoding     "";