Make certificate cache size configurable

docs/user-guide/nginx-configuration/configmap.md

@@ -95,6 +95,7 @@ The following table shows a configuration option's name, type, and the default v
 |[ssl-session-ticket-key](#ssl-session-ticket-key)|string|`<Randomly Generated>`|
 |[ssl-session-timeout](#ssl-session-timeout)|string|"10m"||
 |[ssl-buffer-size](#ssl-buffer-size)|string|"4k"||
+|[ssl-certificate-cache-size](#ssl-certificate-cache-size)|int|1000|
 |[use-proxy-protocol](#use-proxy-protocol)|bool|"false"||
 |[proxy-protocol-header-timeout](#proxy-protocol-header-timeout)|string|"5s"||
 |[enable-aio-write](#enable-aio-write)|bool|"true"||
@@ -701,6 +702,14 @@ Sets the size of the [SSL buffer](https://nginx.org/en/docs/http/ngx_http_ssl_mo
 _References:_
 [https://www.igvita.com/2013/12/16/optimizing-nginx-tls-time-to-first-byte/](https://www.igvita.com/2013/12/16/optimizing-nginx-tls-time-to-first-byte/)
 
+## ssl-certificate-cache-size
+
+Sets the size of cache that stores parsed SSL certificate objects.
+
+The cache helps reduce memory consumption of SSL context per connection. Increase the value if you have huge amount of certificates.
+
+_**default:**_ is 1000.
+
 ## use-proxy-protocol
 
 Enables or disables the [PROXY protocol](https://www.nginx.com/resources/admin-guide/proxy-protocol/) to receive client connection (real IP address) information passed through proxy servers and load balancers such as HAProxy and Amazon Elastic Load Balancer (ELB).

internal/ingress/controller/config/config.go

@@ -413,6 +413,10 @@ type Configuration struct {
 	// Default: false
 	SSLRejectHandshake bool `json:"ssl-reject-handshake"`
 
+	// Sets the size of cache that stores parsed SSL certificate objects.
+	// The cache helps reduce memory consumption of SSL context per connection.
+	SSLCertificateCacheSize int `json:"ssl-certificate-cache-size,omitempty"`
+
 	// Enables or disables the use of the PROXY protocol to receive client connection
 	// (real IP address) information passed through proxy servers and load balancers
 	// such as HAproxy and Amazon Elastic Load Balancer (ELB).
@@ -837,6 +841,7 @@ func NewDefault() Configuration {
 		SSLSessionCacheSize:              sslSessionCacheSize,
 		SSLSessionTickets:                false,
 		SSLSessionTimeout:                sslSessionTimeout,
+		SSLCertificateCacheSize:          1000,
 		EnableBrotli:                     false,
 		EnableAioWrite:                   true,
 		UseGzip:                          false,

rootfs/etc/nginx/lua/certificate.lua

@@ -19,16 +19,7 @@ local DEFAULT_CERT_HOSTNAME = "_"
 local certificate_data = ngx.shared.certificate_data
 local certificate_servers = ngx.shared.certificate_servers
 local ocsp_response_cache = ngx.shared.ocsp_response_cache
-
+local certificate_cache
-local CACHE_SIZE = 1000
-local cache
-do
-  local err
-  cache, err = lrucache.new(CACHE_SIZE)
-  if not cache then
-    return error("failed to create the certificate cache: " .. (err or "unknown"))
-  end
-end
 
 local function get_cert_and_priv_key(pem_cert_key)
   local cert, cert_err = ssl.parse_pem_cert(pem_cert_key)
@@ -232,8 +223,16 @@ function _M.configured_for_current_request()
   return ngx.ctx.cert_configured_for_current_request
 end
 
+function _M.set_cache_size(size)
+  local cache, err = lrucache.new(size)
+  if err then
+    ngx.log(ngx.ERR, string.format("failed to create the certificate cache: %s", tostring(err)))
+  end
+  certificate_cache = cache
+end
+
 function _M.flush_cache()
-  cache:flush_all()
+  certificate_cache:flush_all()
 end
 
 function _M.call()
@@ -258,7 +257,7 @@ function _M.call()
     return
   end
 
-  local cached_entry = cache:get(pem_cert_uid)
+  local cached_entry = certificate_cache:get(pem_cert_uid)
   if cached_entry then
     cert = cached_entry.cert
     priv_key = cached_entry.priv_key
@@ -283,7 +282,7 @@ function _M.call()
       return ngx.exit(ngx.ERROR)
     end
 
-    cache:set(pem_cert_uid, { cert = cert, priv_key = priv_key, der_cert = der_cert })
+    certificate_cache:set(pem_cert_uid, { cert = cert, priv_key = priv_key, der_cert = der_cert })
   end
 
   local clear_ok, clear_err = ssl.clear_certs()

rootfs/etc/nginx/lua/test/certificate_test.lua

@@ -78,7 +78,7 @@ describe("Certificate", function()
 
       ngx.exit = function(status) end
 
-
+      certificate.set_cache_size(1000)
       set_certificate(DEFAULT_CERT_HOSTNAME, DEFAULT_CERT, DEFAULT_UUID)
     end)
 

rootfs/etc/nginx/template/nginx.tmpl

@@ -112,6 +112,7 @@ http {
         else
           certificate = res
           certificate.is_ocsp_stapling_enabled = {{ $cfg.EnableOCSP }}
+          certificate.set_cache_size({{ $cfg.SSLCertificateCacheSize }})
         end
 
         ok, res = pcall(require, "plugins")