Add Lua module to serve SSL Certificates dynamically

internal/ingress/controller/nginx.go

@@ -731,7 +731,7 @@ func clearCertificates(config *ingress.Configuration) {
 	var clearedServers []*ingress.Server
 	for _, server := range config.Servers {
 		copyOfServer := *server
-		copyOfServer.SSLCert = ingress.SSLCert{}
+		copyOfServer.SSLCert = ingress.SSLCert{PemFileName: copyOfServer.SSLCert.PemFileName}
 		clearedServers = append(clearedServers, &copyOfServer)
 	}
 	config.Servers = clearedServers

rootfs/etc/nginx/lua/certificate.lua

@@ -0,0 +1,54 @@
+local ssl = require("ngx.ssl")
+local configuration = require("configuration")
+
+local _M = {}
+
+local function set_pem_cert_key(pem_cert_key)
+  local der_cert, der_cert_err = ssl.cert_pem_to_der(pem_cert_key)
+  if not der_cert then
+    return "failed to convert certificate chain from PEM to DER: " .. der_cert_err
+  end
+
+  local set_cert_ok, set_cert_err = ssl.set_der_cert(der_cert)
+  if not set_cert_ok then
+    return "failed to set DER cert: " .. set_cert_err
+  end
+
+  local der_priv_key, dev_priv_key_err = ssl.priv_key_pem_to_der(pem_cert_key)
+  if not der_priv_key then
+    return "failed to convert private key from PEM to DER: " .. dev_priv_key_err
+  end
+
+  local set_priv_key_ok, set_priv_key_err = ssl.set_der_priv_key(der_priv_key)
+  if not set_priv_key_ok then
+    return "failed to set DER private key: " .. set_priv_key_err
+  end
+end
+
+function _M.call()
+  local hostname, hostname_err = ssl.server_name()
+  if hostname_err then
+    ngx.log(ngx.ERR, "Error getting the hostname, falling back on default certificate: " .. hostname_err)
+    return
+  end
+
+  local pem_cert_key = configuration.get_pem_cert_key(hostname)
+  if not pem_cert_key or pem_cert_key == "" then
+    ngx.log(ngx.ERR, "Certificate not found, falling back on default certificate for hostname: " .. tostring(hostname))
+    return
+  end
+
+  local clear_ok, clear_err = ssl.clear_certs()
+  if not clear_ok then
+    ngx.log(ngx.ERR, "failed to clear existing (fallback) certificates: " .. clear_err)
+    return ngx.exit(ngx.ERROR)
+  end
+
+  local set_pem_cert_key_err = set_pem_cert_key(pem_cert_key)
+  if set_pem_cert_key_err then
+    ngx.log(ngx.ERR, set_pem_cert_key_err)
+    return ngx.exit(ngx.ERROR)
+  end
+end
+
+return _M

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

@@ -0,0 +1,94 @@
+local certificate = require("certificate")
+
+local unmocked_ngx = _G.ngx
+
+describe("Certificate", function()
+  describe("call", function()
+    local ssl = require("ngx.ssl")
+    local match = require("luassert.match")
+
+    ssl.server_name = function() return "hostname", nil end
+    ssl.clear_certs = function() return true, "" end
+    ssl.set_der_cert = function(cert) return true, "" end
+    ssl.set_der_priv_key = function(priv_key) return true, "" end
+
+    before_each(function()
+      ngx.exit = function(status) end
+    end)
+
+    after_each(function()
+      ngx = unmocked_ngx
+    end)
+
+    it("does not clear fallback certificates and logs error message when host is not in dictionary", function()
+      ngx.shared.certificate_data:set("hostname", "")
+
+      spy.on(ngx, "log")
+      spy.on(ssl, "clear_certs")
+      spy.on(ssl, "set_der_cert")
+      spy.on(ssl, "set_der_priv_key")
+
+      assert.has_no.errors(certificate.call)
+      assert.spy(ngx.log).was_called_with(ngx.ERR, "Certificate not found, falling back on default certificate for hostname: hostname")
+      assert.spy(ssl.clear_certs).was_not_called()
+      assert.spy(ssl.set_der_cert).was_not_called()
+      assert.spy(ssl.set_der_priv_key).was_not_called()
+    end)
+
+    it("does not clear fallback certificates and logs error message when the cert is empty for given host", function()
+      spy.on(ngx, "log")
+      spy.on(ssl, "clear_certs")
+      spy.on(ssl, "set_der_cert")
+      spy.on(ssl, "set_der_priv_key")
+
+      assert.has_no.errors(certificate.call)
+      assert.spy(ngx.log).was_called_with(ngx.ERR, "Certificate not found, falling back on default certificate for hostname: hostname")
+      assert.spy(ssl.clear_certs).was_not_called()
+      assert.spy(ssl.set_der_cert).was_not_called()
+      assert.spy(ssl.set_der_priv_key).was_not_called()
+    end)
+
+    it("successfully sets SSL certificate and key when hostname is found in dictionary", function()
+      local _ = match._
+      local pem_cert_key = "-----BEGIN CERTIFICATE-----\nMIID6DCCAlCgAwIBAgIQcfG0mA7BIFqhlnr/Zwh6TzANBgkqhkiG9w0BAQsFADBC\nMR4wHAYDVQQKExVta2NlcnQgZGV2ZWxvcG1lbnQgQ0ExIDAeBgNVBAsMF2hlbnJ5\ndHJhbkBPVFQtSGVucnlUcmFuMB4XDTE4MDcwOTIwMTY1MloXDTI4MDcwOTIwMTY1\nMlowSzEnMCUGA1UEChMebWtjZXJ0IGRldmVsb3BtZW50IGNlcnRpZmljYXRlMSAw\nHgYDVQQLDBdoZW5yeXRyYW5AT1RULUhlbnJ5VHJhbjCCASIwDQYJKoZIhvcNAQEB\nBQADggEPADCCAQoCggEBALIrsgHzjZZyKWPn3rGzTkaj9jADYAMhM+0wY3iky2Dx\ndr2YbKnZbbGxKLfVukYRsUUOK0SnBMTX15fsGanirj2hflMHfGvHilaVkVAkPJgD\nBTf2PkxFff99hS7/Ncz20MR6+E/vqp7Hx7IKDrg9lC9u1n82aotfN3gPhif8HyQu\n+P9cltsr9PewyPe4573WQmzXhTKaFm9+U9xZ2qS1J0DMEizRs45vuM040hxtiwVz\nM4Lm8DVpaYxMBWNI/zo9EZzoSJZH1sYUpTMwhNj+caEX+LK9PCM4Sht/yhPUc6aD\nnIEqraz+bS8dNFH5Ehp7n1SZL7YH6xT6da4F3ci7jEECAwEAAaNRME8wDgYDVR0P\nAQH/BAQDAgWgMBMGA1UdJQQMMAoGCCsGAQUFBwMBMAwGA1UdEwEB/wQCMAAwGgYD\nVR0RBBMwEYIPbXltaW5pa3ViZS5pbmZvMA0GCSqGSIb3DQEBCwUAA4IBgQC/TEpx\nJkL/ek37L2XKwGq96hNT10IZ9yE+RlndNGNY6eAc8y313sXBHTFbDCWQ2s0pWZZS\n+va20dnTQNyWzJAxFpdNvcKOCUGat4RPD/j+pBTEYk5n/oo7s2FWkG8kW6tKDilf\njWHpk7m9uYCO2sOZFiQPR81idR5PLox46SpJmIhDVfCi6VS4N+8fAT8Tbt9xkPmS\nmODhpnuIUt0NVTi62eqnxeO185qAt73xhz9Gj1KHntAK1ebcx0k3UxKRXQp9WY76\nF39sSz8OuhEhvv9ayl6uS6ZdSLvvb6kJrRRneKr01ridCOtiYB7cuXykDL1c6PUk\nugxDgTyCjiuPnRl0CLwxWT659PVozA2SO1YCW6UcoGdj2KMvsXezeWKpNGx3NHXO\nufdlxSbzWlamn+sPunWP3v2tfV0J8sHG3n1roeBO2N52197/ennGuCZfnF8C5MoG\n9YfMjKg9Z03G8sDpk9g5bHp9p28TO1X+Ht30PQzkUNhx3fjTO2DDvCyGk2k=\n-----END CERTIFICATE-----\n\n-----BEGIN PRIVATE KEY-----\nMIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQCyK7IB842Wcilj\n596xs05Go/YwA2ADITPtMGN4pMtg8Xa9mGyp2W2xsSi31bpGEbFFDitEpwTE19eX\n7Bmp4q49oX5TB3xrx4pWlZFQJDyYAwU39j5MRX3/fYUu/zXM9tDEevhP76qex8ey\nCg64PZQvbtZ/NmqLXzd4D4Yn/B8kLvj/XJbbK/T3sMj3uOe91kJs14UymhZvflPc\nWdqktSdAzBIs0bOOb7jNONIcbYsFczOC5vA1aWmMTAVjSP86PRGc6EiWR9bGFKUz\nMITY/nGhF/iyvTwjOEobf8oT1HOmg5yBKq2s/m0vHTRR+RIae59UmS+2B+sU+nWu\nBd3Iu4xBAgMBAAECggEBAIbuUIDp0fB9xJrEnwI0qLMWuPrjk3LLUmfunWZgZyWj\nuCkdpi17XHeVkyCl28v02itR77KuSg5I6B1F0Km34f0KsIBwyulU1I999e6bgsgc\ngXdAJS3d8u3qQVK2NChlQvWJq0PeXXiiE7nhpAQjnnXNmuP8cfPayEdEenUNmwfq\nxjEh2/oDzUTPD/4z5Hpw8n728SItgBolMNgGvmv5cC4JNLqujCUPwkLiZ3a2YbTY\nrmOO1xDkZnQWqyNP+baOwYwpu/kISPM3IveP5GGBNQsUsDxs6t80HNW/w8Ry0f50\n+gNTIuJVOLXfpVLIo87wTMEtRAqMzT4vxQIi+vj2XYECgYEA6QftSRKqur1G4P6Y\n9cseDnljJFWIjqex2q3NrvMaHbnlXp6AtPROoNz6L8H+PnBy8o1yZJwWnhKTvPaD\nsi+a1g7dqQIM4TjKLlidV57lt5ENw4ueW1o7Jbk75gawLhrBPSCFxR5xSqF+kQxn\nmWGjLnZoomD6fM2CG7EF1fg+wjsCgYEAw7t6db9tjGGM9J0rUe+jVtxMWiG9ArT0\nhmaLZQlKrOSFeEf8c4ZYBNxp/X+/jg0GWBX8P4KRubAz6bbn0A+07K9TClrvMFWq\nveqnK1JUsMGWsYQPp8dX8VS/jOFzYdiji9Ekyzs9RiXW8jzp0wzrccSjEr0de8HK\niEa9CH7cZ7MCgYB1V5mD51NzbyZG281YT+yVq0hiHnQCKa1kiYp+I0ouV9KJP9Vd\nyXvigwO0ksIc3PD09Ib65KJ6/K3KRHPygQg97ARwO2kS7E7a4aJxYcEZG4DLy/10\n0M3h5BGmdg23WZ+e0UarCPZRd1rNXWq5kLHkDpoH0j+wIqf2m8Bti3DGywKBgBEK\nn6zkz9rrG2So0n69yJDleVhXm6dCrg+NmhFf77qB4wUH73j3d25k6m2B0+HATI8a\nyu2Upq9uIfb1T9WTqIL6+NXr+OtSah1C8u8YqfsBv+cQwnQvLP78C/luH6ejPwoL\nWZLAQ6N54+8PUqRneZBcOH6HLKv7wXCACDFXKkV1AoGAfDb5GJ0NsovWhLfU5WEB\nSfdzHBplbp72q08S0aqTNm0wlTiCGYgm2Lle4IaOGoJ+7ipirL0KzuwisAZJFTvJ\nhsMqOmH/Ckledmf2JpLxyg8KB5KVA+RVQkrfVEv8yhqLcKQU6Z2n4jSTon7hXb1T\nf8neDpZ8DwO0W9cOdYLYyTg=\n-----END PRIVATE KEY-----"
+      ngx.shared.certificate_data:set("hostname", pem_cert_key)
+
+      spy.on(ngx, "log")
+      spy.on(ssl, "set_der_cert")
+      spy.on(ssl, "set_der_priv_key")
+
+      assert.has_no.errors(certificate.call)
+      assert.spy(ngx.log).was_not_called_with(ngx.ERR, _)
+      assert.spy(ssl.set_der_cert).was_called_with(ssl.cert_pem_to_der(pem_cert_key))
+      assert.spy(ssl.set_der_priv_key).was_called_with(ssl.priv_key_pem_to_der(pem_cert_key))
+    end)
+
+    it("logs error message when certificate in dictionary is invalid", function()
+      ngx.shared.certificate_data:set("hostname", "something invalid")
+
+      spy.on(ngx, "log")
+      spy.on(ssl, "set_der_cert")
+      spy.on(ssl, "set_der_priv_key")
+
+      assert.has_no.errors(certificate.call)
+      assert.spy(ngx.log).was_called_with(ngx.ERR, "failed to convert certificate chain from PEM to DER: PEM_read_bio_X509_AUX() failed")
+      assert.spy(ssl.set_der_cert).was_not_called()
+      assert.spy(ssl.set_der_priv_key).was_not_called()
+    end)
+
+    it("does not clear fallback certificates and logs error message when hostname could not be fetched", function()
+      ssl.server_name = function() return nil, "error" end
+
+      spy.on(ngx, "log")
+      spy.on(ssl, "clear_certs")
+      spy.on(ssl, "set_der_cert")
+      spy.on(ssl, "set_der_priv_key")
+
+      assert.has_no.errors(certificate.call)
+      assert.spy(ngx.log).was_called_with(ngx.ERR, "Error getting the hostname, falling back on default certificate: error")
+      assert.spy(ssl.clear_certs).was_not_called()
+      assert.spy(ssl.set_der_cert).was_not_called()
+      assert.spy(ssl.set_der_priv_key).was_not_called()
+    end)
+  end)
+end)

rootfs/etc/nginx/template/nginx.tmpl

@@ -85,6 +85,15 @@ http {
         else
           monitor = res
         end
+
+        {{ if $all.DynamicCertificatesEnabled }}
+        ok, res = pcall(require, "certificate")
+        if not ok then
+          error("require failed: " .. tostring(res))
+        else
+          certificate = res
+        end
+        {{ end }}
     }
 
     {{ if $all.DynamicConfigurationEnabled }}
@@ -775,6 +784,12 @@ stream {
         ssl_stapling                            on;
         ssl_stapling_verify                     on;
         {{ end }}
+
+        {{ if and (not $all.DisableLua) $all.DynamicCertificatesEnabled}}
+        ssl_certificate_by_lua_block {
+            certificate.call()
+        }
+        {{ end }}
         {{ end }}
 
         {{ if not (empty $server.AuthTLSError) }}