Add Nginx config with docker secrets

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

contrib/nginx/README.md

@@ -0,0 +1,46 @@
+### Create a .htaccess:
+
+```
+$ sudo apt-get install apache2-utils
+```
+
+```
+$ htpasswd -c openfaas.htpasswd admin
+New password: 
+Re-type new password: 
+Adding password for user admin
+```
+
+Example:
+
+```
+$ cat openfaas.htpasswd 
+admin:$apr1$BgwAfB5i$dfzQPXy6VliPCVqofyHsT.
+```
+
+### Create a secret in the cluster
+
+```
+$ docker secret create --label openfaas openfaas_htpasswd openfaas.htpasswd 
+q70h0nsj9odbtv12vrsijcutx
+```
+
+You can now see the secret created:
+
+```
+$ docker secret ls
+ID                          NAME                DRIVER              CREATED             UPDATED
+q70h0nsj9odbtv12vrsijcutx   openfaas_htpasswd                       13 seconds ago      13 seconds ago
+```
+
+### Launch nginx
+
+Build gwnginx from contrib directory. 
+
+```
+$ docker service rm gwnginx ; \
+ docker service create --network=func_functions \
+   --secret openfaas_htpasswd --publish 8081:8080 --name gwnginx gwnginx 
+```
+
+