18785: edit documentation, addressing review comments

Arvados-DCO-1.1-Signed-off-by: Javier Bértoli <jbertoli@curii.com>

diff --git a/doc/install/salt-single-host.html.textile.liquid b/doc/install/salt-single-host.html.textile.liquid
index 3610741b41a0638e0a1f05560723ce43c614d206..2691332fd985d49ac84ed0a050179a837be01822 100644 (file)
--- a/doc/install/salt-single-host.html.textile.liquid
+++ b/doc/install/salt-single-host.html.textile.liquid
@@ -87,7 +87,9 @@ cp -r config_examples/single_host/single_hostname local_config_dir
 
 Edit the variables in the <i>local.params</i> file. Pay attention to the <b>*_PORT, *_TOKEN</b> and <b>*KEY</b> variables.
 
-The <i>single_host</i> examples use self-signed SSL certificates, which are deployed using the same mechanism used to deploy custom certificates.
+The <i>single_host</i> examples use self-signed SSL certificates by default, which are deployed using the same mechanism used to deploy custom certificates.
+
+When setting (SSL_MODE=lets-encrypt), please note: When using AWS, EC2 instances can have a default hostname that ends with `amazonaws.com`. Let's Encrypt has a blacklist of domain names for which it will not issue certificates, and that blacklist includes the `amazonaws.com` domain. In order to use Let's Encrypt certificates on AWS EC2, you will need to bring your own domain name and point a hostname in that domain at your EC2 instance.
 
 h3(#single_host_multiple_hostnames). Single host / multiple hostnames (Alternative configuration)
 <notextile>