update Nginx guide with changes (#6466)

* update Nginx guide with changes

* Fix URL for security guide

* Remove enable TLS statement

* update header title

2 files changed, 59 insertions, 21 deletions

diff --git a/docs/Running-behind-nginx.md b/docs/Running-behind-nginx.md
index 12999c2031..81ebc1a756 100644
--- a/docs/Running-behind-nginx.md
+++ b/docs/Running-behind-nginx.md
@@ -1,9 +1,43 @@
-# Netdata via nginx
+# Running Netdata behind Nginx
 
-To pass Netdata via a nginx, use this:
+## Intro
+
+[Nginx](https://nginx.org/en/) is an HTTP and reverse proxy server, a mail proxy server, and a generic TCP/UDP proxy server used to host websites and applications of all sizes. 
+
+The software is known for its low impact on memory resources, high scalability, and its modular, event-driven architecture which can offer secure, predictable performance.
+
+## Why Nginx
+
+- By default, Nginx is fast and lightweight out of the box.
+
+- Nginx is used and useful in cases when you want to access different instances of Netdata from a single server.
+
+- Password-protect access to Netdata, until distributed authentication is implemented via the Netdata cloud Sign In mechanism.
+
+- A proxy was necessary to encrypt the communication to netdata, until v1.16.0, which provided TLS (HTTPS) support.
+
+## Nginx configuration file
+
+All Nginx configurations can be found in the `/etc/nginx/` directory. The main configuration file is `/etc/nginx/nginx.conf`. Website or app-specific configurations can be found in the `/etc/nginx/site-available/` directory.
+
+Configuration options in Nginx are known as directives. Directives are organized into groups known as blocks or contexts. The two terms can be used interchangeably.
+
+Depending on your installation source, you’ll find an example configuration file at `/etc/nginx/conf.d/default.conf` or `etc/nginx/sites-enabled/default`, in some cases you may have to manually create the `sites-available` and `sites-enabled` directories. 
+
+You can edit the Nginx configuration file with Nano, Vim or any other text editors you are comfortable with.
+
+After making changes to the configuration files:
+
+- Test Nginx configuration with `nginx -t`.
+
+- Restart Nginx to effect the change with `/etc/init.d/nginx restart` or `service nginx restart`.
+
+## Ways to access Netdata via Nginx
 
 ### As a virtual host
 
+With this method instead of `SERVER_IP_ADDRESS:19999`, the Netdata dashboard can be accessed via a human-readable URL such as `netdata.example.com` used in the configuration below. 
+
 ```
 upstream backend {
     # the Netdata server
@@ -30,9 +64,11 @@ server {
     }
 }
 ```
-
 ### As a subfolder to an existing virtual host
 
+This method is recommended when Netdata is to be served from a subfolder (or directory). 
+In this case, the virtual host `netdata.example.com` already exists and Netdata has to be accessed via `netdata.example.com/netdata/`.
+
 ```
 upstream netdata {
     server 127.0.0.1:19999;
@@ -69,7 +105,9 @@ server {
 }
 ```
 
-### As a subfolder for multiple Netdata servers, via one nginx
+### As a subfolder for multiple Netdata servers, via one Nginx
+
+This is the recommended configuration when one Nginx will be used to manage multiple Netdata servers via subfolders. 
 
 ```
 upstream backend-server1 {
@@ -114,25 +152,25 @@ Of course you can add as many backend servers as you like.
 
 Using the above, you access Netdata on the backend servers, like this:
 
-- `http://nginx.server/netdata/server1/` to reach `backend-server1`
-- `http://nginx.server/netdata/server2/` to reach `backend-server2`
+- `http://netdata.example.com/netdata/server1/` to reach `backend-server1`
+- `http://netdata.example.com/netdata/server2/` to reach `backend-server2`
 
-### Using TLS communication
+### Encrypt the communication between Nginx and Netdata
 
-In case Netdata's web server has been [configured to use TLS](../web/server/#enabling-tls-support), you must also encrypt the communication between Nginx and Netdata.
-
-To enable encryption, first [enable TLS/SSL on Nginx](http://nginx.org/en/docs/http/configuring_https_servers.html) and then put the following in the location section of your Nginx configuration:
+In case Netdata's web server has been [configured to use TLS](../web/server/#enabling-tls-support), it is necessary to specify inside the Nginx configuration that the final destination is using TLS. To do this, please, append the following parameters in your `nginx.conf`
 
 ```
 proxy_set_header X-Forwarded-Proto https;
 proxy_pass https://localhost:19999;
 ```
 
-If nginx is not configured as described here, you will probably receive the error `SSL_ERROR_RX_RECORD_TOO_LONG`.
+Optionally it is also possible to [enable TLS/SSL on Nginx](http://nginx.org/en/docs/http/configuring_https_servers.html), this way the user will encrypt not only the communication between Nginx and Netdata but also between the user and Nginx.
+
+If Nginx is not configured as described here, you will probably receive the error `SSL_ERROR_RX_RECORD_TOO_LONG`.
 
 ### Enable authentication
 
-Create an authentication file to enable basic authentication via Nginx. Do not use authentication without having first [enabled TLS](#using-tls-communication)!
+Create an authentication file to enable basic authentication via Nginx, this secures your Netdata dashboard.
 
 If you don't have an authentication file, you can use the following command:
 
@@ -151,7 +189,7 @@ server {
 }
 ```
 
-## limit direct access to Netdata
+## Limit direct access to Netdata
 
 If your Nginx is on `localhost`, you can use this to protect your Netdata:
 
@@ -162,7 +200,7 @@ If your Nginx is on `localhost`, you can use this to protect your Netdata:
 
 ---
 
-You can also use a unix domain socket. This will also provide a faster route between nginx and Netdata:
+You can also use a unix domain socket. This will also provide a faster route between Nginx and Netdata:
 
 ```
 [web]
@@ -170,7 +208,7 @@ You can also use a unix domain socket. This will also provide a faster route bet
 ```
 _note: Netdata v1.8+ support unix domain sockets_
 
-At the nginx side, use something like this to use the same unix domain socket:
+At the Nginx side, use something like this to use the same unix domain socket:
 
 ```
 upstream backend {
@@ -181,7 +219,7 @@ upstream backend {
 
 ---
 
-If your nginx server is not on localhost, you can set:
+If your Nginx server is not on localhost, you can set:
 
 ```
 [web]
@@ -193,9 +231,9 @@ _note: Netdata v1.9+ support `allow connections from`_
 
 `allow connections from` accepts [Netdata simple patterns](../libnetdata/simple_pattern/) to match against the connection IP address.
 
-## prevent the double access.log
+## Prevent the double access.log
 
-nginx logs accesses and Netdata logs them too. You can prevent Netdata from generating its access log, by setting this in `/etc/netdata/netdata.conf`:
+Nginx logs accesses and Netdata logs them too. You can prevent Netdata from generating its access log, by setting this in `/etc/netdata/netdata.conf`:
 
 ```
 [global]
@@ -204,7 +242,7 @@ nginx logs accesses and Netdata logs them too. You can prevent Netdata from gene
 
 ## SELinux
 
-If you get an 502 Bad Gateway error you might check your nginx error log:
+If you get an 502 Bad Gateway error you might check your Nginx error log:
 
 ```sh
 # cat /var/log/nginx/error.log:
@@ -214,4 +252,4 @@ If you get an 502 Bad Gateway error you might check your nginx error log:
 If you see something like the above, chances are high that SELinux prevents nginx from connecting to the backend server. To fix that, just use this policy: `setsebool -P httpd_can_network_connect true`.
 
 
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\ No newline at end of file
diff --git a/docs/netdata-security.md b/docs/netdata-security.md
index 955abebd8a..a905717d93 100644
--- a/docs/netdata-security.md
+++ b/docs/netdata-security.md
@@ -89,7 +89,7 @@ In Netdata v1.9+ there is also access list support, like this:
 
 #### Use an authenticating web server in proxy mode
 
-Use one web server to provide authentication in front of **all your Netdata servers**. So, you will be accessing all your Netdata with URLs like `http://{HOST}/netdata/{NETDATA_HOSTNAME}/` and authentication will be shared among all of them (you will sign-in once for all your servers). Instructions are provided on how to set the proxy configuration to have Netdata run behind [nginx](Running-behind-nginx.md#netdata-via-nginx), [Apache](Running-behind-apache.md), [lighthttpd](Running-behind-lighttpd.md#netdata-via-lighttpd-v14x) and [Caddy](Running-behind-caddy.md#netdata-via-caddy).
+Use one web server to provide authentication in front of **all your Netdata servers**. So, you will be accessing all your Netdata with URLs like `http://{HOST}/netdata/{NETDATA_HOSTNAME}/` and authentication will be shared among all of them (you will sign-in once for all your servers). Instructions are provided on how to set the proxy configuration to have Netdata run behind [nginx](Running-behind-nginx.md), [Apache](Running-behind-apache.md), [lighthttpd](Running-behind-lighttpd.md#netdata-via-lighttpd-v14x) and [Caddy](Running-behind-caddy.md#netdata-via-caddy).
 
 To use this method, you should firewall protect all your Netdata servers, so that only the web server IP will allowed to directly access Netdata. To do this, run this on each of your servers (or use your firewall manager):