Use system self signed certificate as default SSL certificate

controllers/nginx/Dockerfile

@@ -14,10 +14,12 @@
 
 FROM gcr.io/google_containers/nginx-slim:0.8
 
-RUN apt-get update && apt-get install -y \
+RUN DEBIAN_FRONTEND=noninteractive apt-get update && apt-get install -y \
   diffutils \
+  ssl-cert \
   --no-install-recommends \
-  && rm -rf /var/lib/apt/lists/*
+  && rm -rf /var/lib/apt/lists/* \
+  && make-ssl-cert generate-default-snakeoil --force-overwrite
 
 COPY nginx-ingress-controller /
 COPY nginx.tmpl /etc/nginx/template/nginx.tmpl

controllers/nginx/README.md

@@ -138,16 +138,15 @@ Check the [example](examples/tls/README.md)
 
 ### Default SSL Certificate
 
-NGINX provides the option [default_server](http://nginx.org/en/docs/http/server_names.html) to allow a catch-all server in case of request with a not configured server name. This configuration works without issues for HTTP traffic.
-In case of HTTPS NGINX requires a certificate. For this reason the Ingress controller provides the flag `--default-ssl-certificate`. The secret behind this flag contains the default certificate to be used in the mentioned case.
-If this flag is not provided NGINX will reject the request with the HTTP code 444.
+NGINX provides the option serve rname [_](http://nginx.org/en/docs/http/server_names.html) as a catch-all in case of requests that do not match one of the configured server names. This configuration works without issues for HTTP traffic. In case of HTTPS NGINX requires a certificate. For this reason the Ingress controller provides the flag `--default-ssl-certificate`. The secret behind this flag contains the default certificate to be used in the mentioned case.
+If this flag is not provided NGINX will use a self signed certificate.
 
 Running without the flag `--default-ssl-certificate`:
 
 ```
-$ curl -v https://10.2.78.7:443
+$ curl -v https://10.2.78.7:443 -k
 * Rebuilt URL to: https://10.2.78.7:443/
-*   Trying 10.2.78.7...
+*   Trying 10.2.78.4...
 * Connected to 10.2.78.7 (10.2.78.7) port 443 (#0)
 * ALPN, offering http/1.1
 * Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
@@ -156,9 +155,39 @@ $ curl -v https://10.2.78.7:443
   CApath: /etc/ssl/certs
 * TLSv1.2 (OUT), TLS header, Certificate Status (22):
 * TLSv1.2 (OUT), TLS handshake, Client hello (1):
-* Unknown SSL protocol error in connection to 10.2.78.7:443
-* Closing connection 0
-curl: (35) Unknown SSL protocol error in connection to 10.2.78.7:443
+* TLSv1.2 (IN), TLS handshake, Server hello (2):
+* TLSv1.2 (IN), TLS handshake, Certificate (11):
+* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
+* TLSv1.2 (IN), TLS handshake, Server finished (14):
+* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
+* TLSv1.2 (OUT), TLS change cipher, Client hello (1):
+* TLSv1.2 (OUT), TLS handshake, Finished (20):
+* TLSv1.2 (IN), TLS change cipher, Client hello (1):
+* TLSv1.2 (IN), TLS handshake, Finished (20):
+* SSL connection using TLSv1.2 / ECDHE-RSA-AES128-GCM-SHA256
+* ALPN, server accepted to use http/1.1
+* Server certificate:
+*    subject: CN=foo.bar.com
+*    start date: Apr 13 00:50:56 2016 GMT
+*    expire date: Apr 13 00:50:56 2017 GMT
+*    issuer: CN=foo.bar.com
+*    SSL certificate verify result: self signed certificate (18), continuing anyway.
+> GET / HTTP/1.1
+> Host: 10.2.78.7
+> User-Agent: curl/7.47.1
+> Accept: */*
+>
+< HTTP/1.1 404 Not Found
+< Server: nginx/1.11.1
+< Date: Thu, 21 Jul 2016 15:38:46 GMT
+< Content-Type: text/html
+< Transfer-Encoding: chunked
+< Connection: keep-alive
+< Strict-Transport-Security: max-age=15724800; includeSubDomains; preload
+<
+<span>The page you're looking for could not be found.</span>
+
+* Connection #0 to host 10.2.78.7 left intact
 ```
 
 Specifyng `--default-ssl-certificate=default/foo-tls`:

controllers/nginx/configuration.md

@@ -33,7 +33,7 @@ Please check the [custom configuration](examples/custom-configuration/README.md)
 
 #### Annotations
 
-The following annotaitons are supported:
+The following annotations are supported:
 
 |Name                 |type|
 |---------------------------|------|

controllers/nginx/controller.go

@@ -870,13 +870,22 @@ func (lbc *loadBalancerController) createServers(data []interface{}) map[string]
 	servers := make(map[string]*nginx.Server)
 
 	pems := lbc.getPemsFromIngress(data)
-	if lbc.defSSLCertificate != "" {
-		ngxCert, err := lbc.getPemCertificate(lbc.defSSLCertificate)
-		if err == nil {
-			pems["_"] = ngxCert
-		} else {
-			glog.Warningf("%v", err)
-		}
+
+	var ngxCert nginx.SSLCert
+	var err error
+
+	if lbc.defSSLCertificate == "" {
+		// use system certificated generated at image build time
+		cert, key := getFakeSSLCert()
+		ngxCert, err = lbc.nginx.AddOrUpdateCertAndKey("system-snake-oil-certificate", cert, key)
+	} else {
+		ngxCert, err = lbc.getPemCertificate(lbc.defSSLCertificate)
+	}
+
+	if err == nil {
+		pems["_"] = ngxCert
+	} else {
+		glog.Warningf("%v", err)
 	}
 
 	for _, ingIf := range data {

controllers/nginx/nginx.tmpl

@@ -180,16 +180,6 @@ http {
     {{ end }}
 
     {{ range $server := .servers }}
-    {{/* Check for default SSL backend */}}
-    {{ if and (eq $server.Name "_") (not $server.SSL) -}}
-    server {
-        server_name {{ $server.Name }};
-        listen 443;
-        # return protocol error.
-        return 444;
-    }
-    {{ end }}
-
     server {
         server_name {{ $server.Name }};
         listen 80{{ if $cfg.useProxyProtocol }} proxy_protocol{{ end }};
@@ -289,8 +279,11 @@ http {
     }
     {{ end }}
 
-    # default server, including healthcheck
+    # default server, used for NGINX healthcheck and access to nginx stats
     server {
+        # Use the port 18080 (random value just to avoid known ports) as default port for nginx.
+        # Changing this value requires a change in:
+        # https://github.com/kubernetes/contrib/blob/master/ingress/controllers/nginx/nginx/command.go#L104
         listen 18080 default_server reuseport backlog={{ .backlogSize }};
 
         location /healthz {

controllers/nginx/nginx/ssl.go

@@ -108,7 +108,7 @@ func (nginx *Manager) commonNames(pemFileName string) ([]string, error) {
 		cn = append(cn, cert.DNSNames...)
 	}
 
-	glog.V(2).Infof("found %v common names: %v\n", cn, len(cn))
+	glog.V(3).Infof("found %v common names: %v\n", cn, len(cn))
 	return cn, nil
 }
 

controllers/nginx/utils.go

@@ -18,6 +18,7 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 	"strings"
 	"time"
@@ -273,3 +274,24 @@ func isNGINXIngress(ing *extensions.Ingress) bool {
 	class := ingAnnotations(ing.ObjectMeta.Annotations).ingressClass()
 	return class == "" || class == nginxIngressClass
 }
+
+const (
+	snakeOilPem = "/etc/ssl/certs/ssl-cert-snakeoil.pem"
+	snakeOilKey = "/etc/ssl/private/ssl-cert-snakeoil.key"
+)
+
+// getFakeSSLCert returns the snake oil ssl certificate created by the command
+// make-ssl-cert generate-default-snakeoil --force-overwrite
+func getFakeSSLCert() (string, string) {
+	cert, err := ioutil.ReadFile(snakeOilPem)
+	if err != nil {
+		return "", ""
+	}
+
+	key, err := ioutil.ReadFile(snakeOilKey)
+	if err != nil {
+		return "", ""
+	}
+
+	return string(cert), string(key)
+}