Add SSH tunnel documentation for remote Grafana access

guides/common/modules/proc_retrieving-metrics-in-the-web-ui.adoc

@@ -1,15 +1,81 @@
 :_mod-docs-content-type: PROCEDURE
-
-[id="retrieving-metrics-in-the-web-ui_{context}"]
-= Retrieving metrics in the web UI
-
-[role="_abstract"]
-You can view the Grafana dashboard, which displays widgets with the values of metrics.
-You can add and remove metrics to suit your requirements.
-You can also select the time span displayed for each widget.
-
-.Procedure
-* Open the following URL in a browser: http://_{foreman-example-com}_:3000
+
+  [id="retrieving-metrics-in-the-web-ui_{context}"]
+  = Retrieving metrics in the web UI
+
+  [role="_abstract"]
+  You can view the Grafana dashboard, which displays widgets with the values of metrics.
+  You can add and remove metrics to suit your requirements.
+  You can also select the time span displayed for each widget.
+
+  .Procedure
+  * Open the following URL in a browser: http://_{foreman-example-com}_:3000
+
+  [id="accessing-grafana-remotely_{context}"]
+  == Accessing Grafana remotely using an SSH tunnel
+
+  By default, Grafana runs on `http://localhost:3000` on the {ProjectServer} and is only accessible locally.
+  To access Grafana from a remote workstation, create an SSH tunnel that forwards your local port 3000 to the
+  {ProjectServer} port 3000.
+
+  .Procedure for Linux or macOS
+
+  . On your local workstation, create an SSH tunnel:
+  +
+  [options="nowrap", subs="verbatim,quotes,attributes"]
+  ----
+  # ssh -L 3000:localhost:3000 root@_{foreman-example-com}_ -N
+  ----
+  +
+  The `-L` flag creates the port forwarding tunnel, and `-N` prevents executing any remote commands.
+  Keep this terminal session open while accessing Grafana.
+
+  . Open your web browser and navigate to: http://localhost:3000
+
+  .Procedure for Windows using PuTTY
+
+  . Open PuTTY and enter your {ProjectServer} hostname or IP address.
+  . In the left menu, navigate to *Connection* -> *SSH* -> *Tunnels*.
+  . Configure the port forwarding:
+  * *Source port*: `3000`
+  * *Destination*: `localhost:3000`
+  * Click *Add*.
+  . Return to the *Session* category and connect to your {ProjectServer}.
+  . After connecting, open your web browser and navigate to: http://localhost:3000
+
+  .Procedure for Windows using PowerShell or Command Prompt
+
+  . If you have OpenSSH installed on Windows 10 or later, open PowerShell or Command Prompt and create an SSH tunnel:
+  +
+  [options="nowrap", subs="verbatim,quotes,attributes"]
+  ----
+  # ssh -L 3000:localhost:3000 root@_{foreman-example-com}_ -N
+  ----
+  +
+  Keep this window open while accessing Grafana.
+
+  . Open your web browser and navigate to: http://localhost:3000
+
+  .Running the SSH tunnel in the background on Linux or macOS
+
+  To run the tunnel in the background:
+
+  [options="nowrap", subs="verbatim,quotes,attributes"]
+  ----
+  # ssh -f -L 3000:localhost:3000 root@_{foreman-example-com}_ -N
+  ----
+
+  The `-f` flag runs the SSH connection in the background.
+
+  To close the background tunnel:
+
+  [options="nowrap", subs="verbatim,quotes,attributes"]
+  ----
+  # ps aux | grep "3000:localhost:3000"
+  # kill _PID_
+  ----
+
+  Replace _PID_ with the process ID from the previous command.
 
 .Additional resources
 * https://grafana.com/[Grafana Labs website]