Update Grafana bridge classic setup documentation for gpfs v.5.1.1

Author: Helene

docs/CLASSIC_SETUP.md

@@ -4,16 +4,17 @@
 ### Prerequisites
 
 Before installing the IBM Spectrum Scale bridge for Grafana you must install the software prerequisites. Those are:
-1. [Performance Monitoring tool](https://www.ibm.com/support/knowledgecenter/en/STXKQY_5.0.5/com.ibm.spectrum.scale.v5r05.doc/bl1adv_PMToverview.htm) installed and configured on your IBM Spectrum Scale device
-2. On the [collector node](https://www.ibm.com/support/knowledgecenter/en/STXKQY_5.0.5/com.ibm.spectrum.scale.v5r05.doc/bl1adv_configurecollector.htm) the following software need to be installed:
+1. [Performance Monitoring tool](https://www.ibm.com/docs/en/spectrum-scale/5.1.1?topic=monitoring-using-performance-tool) installed and configured on your IBM Spectrum Scale device
+2. [Performance monitoring API key](https://www.ibm.com/docs/en/spectrum-scale/5.1.1?topic=tool-configuring-performance-monitoring-api-keys) generated for the IBM Spectrum Scale Performance Monitoring Bridge.
+3. On the [collector node](https://www.ibm.com/docs/en/spectrum-scale/5.1.1?topic=tool-configuring-collector) the following software need to be installed:
 - [Python3.6](https://www.python.org/downloads/release/python-369/)
 - [CherryPy](https://cherrypy.org/)
 
 
 
 ### Dependencies
 This package could be used for: 
-- IBM Spectrum Scale devices having minimum release level 5.0.5 FP2 and above
+- IBM Spectrum Scale devices having minimum release level 5.1.1 and above
 - Grafana 7.1.0 and above
 
 To use this tool on the **older** IBM Spectrum Scale devices please refer to the [SUPPORT_MATRIX](/docs/SUPPORT_MATRIX.md) file.
@@ -24,7 +25,7 @@ To use this tool on the **older** IBM Spectrum Scale devices please refer to the
 
 #### Step 1. Ensure that IBM Spectrum Scale meets prerequisite conditions
 
-The IBM Spectrum Scale system must run 5.0.5.2 or above. Run mmlsconfig to view the current configuration data of a GPFS™ cluster).
+The IBM Spectrum Scale system must run 5.1.1 or above. Run mmlsconfig to view the current configuration data of a GPFS™ cluster).
 
 The bridge works in permanent communication with the pmcollector. Therefore it is recommended to install and run this tool directly on a pmcollector node.
 
@@ -39,9 +40,28 @@ Check the SUPPORT_MATRIX file for the recommended version.
 
 
 
-#### Step 3. Set up IBM Spectrum Scale Performance Monitoring Bridge
+#### Step 3. Create Performance monitoring API key for the IBM Spectrum Scale Performance Monitoring Bridge
 
-Clone the repository using git in your favorite directory on the collector node. Alternatively download the zip package and unpack it :
+On the collector node run the following command:
+
+```shell
+# mmperfmon config add --apikey scale_grafana
+```
+
+Make a note of the displayed 32 hexadecimal digits sequence in the output, representing API key value.
+
+```shell
+{
+    "key": "ad270b0a-840b-494f-8513-110b6b28b479",
+    "comment": "user comment"
+}
+```
+
+
+
+#### Step 4. Set up IBM Spectrum Scale Performance Monitoring Bridge
+
+Clone the repository using git in your favourite directory on the collector node. Alternatively download the zip package and unpack it :
 
 ```shell
 # git clone https://github.com/IBM/ibm-spectrum-scale-bridge-for-grafana.git
@@ -52,9 +72,11 @@ Start the bridge application by issuing:
 ```shell
 # cd source/
 
-# python3 zimonGrafanaIntf.py 
+# python3 zimonGrafanaIntf.py --apiKeyValue
 ```
 
+You will be prompted by a command line interface to enter the 'password'. You can also pass the key value directly (not recommended) by the zimonGrafanaIntf.py invocation following the '--apiKeyValue' input parameter name, or alternatively, store the key value in the config.ini file. For more options configuring and invoking API key please read the [WiKi](https://github.com/IBM/ibm-spectrum-scale-bridge-for-grafana/wiki/Configuring-a-performance-monitoring-API-key-for-the-IBM-Spectrum-Scale-Performance-Monitoring-Bridge) article.
+
 If the bridge did establish the connection to the specified pmcollector and the initialization of the metadata was performed successfully, you should get the message "server started" at the end of line. Otherwise check the zserver.log stored in the zimonGrafanaIntf  directory.  Additionally, check the pmcollector service running properly by issuing:
 
 ```shell
@@ -63,13 +85,13 @@ If the bridge did establish the connection to the specified pmcollector and the
 
 
 
-#### Step 4. Install Grafana
+#### Step 5. Install Grafana
 
 Download and install [Grafana](https://grafana.com/get) according to the given instructions. Before you start Grafana for the first time, check [the configuration options](http://docs.grafana.org/installation/configuration/) for port settings. Start the Grafana server as it described on the Grafana configuration pages.
 
 
 
-#### Step 5. Establish connection to the running bridge in Grafana
+#### Step 6. Establish connection to the running bridge in Grafana
 
 Define a new data source (Data Sources -> Add New)