Warm Spare PBX 15+ Setup

Introduction

This guide will walk you through the process of setting up a warm spare server.

This article assumes the following:

• You have an existing PBX system that will be your primary server.

• You have an identical PBX system that will be your secondary server.

• The two servers can communicate on an IP level.

The Warm Spare setup on PBX 15+ has changed from the way it used to be in older versions.  
We are now using the Filestore ,  API and Backup & Restore modules for the Warm spare Backup configuration, so we need to ensure that all 3 mentioned modules are present in both Primary and Secondary server.

We have to follow below mentioned steps in order to setup PBX 15+ Warmspare setup.  

NOTE  - one primary difference in this latest iteration of warm spare functionality is that the majority of the configuration is done on the PRIMARY system and not the Warmspare!

How to add the Warm Spare Server on the Primary Server

the process needs to send data from the primary to the warmspare. We can either use FTP or SSH protocol to perform this task using Filestore module (SSH is the recommended path) 

SSH Configuration 

In this section, we will describe how to configure "SSH" to use for Warm Spare setup. 
First, we will set up shared keys between the two servers so they can communicate across SSH on port 22. PBX 15+ onward there is no need of generating SSH Keys for the Primary server. Backup & Restore module will take care of generating SSH Keys by itself. But we have to copy the Primary Server SSH Keys to Secondary server to ensure that Primary can communicate with Secondary server easily.
We can use any one of the following 2 methods to copy the SSH keys to Secondary (Warm spare) server. 

1. Manually copy the SSH Keys to Secondary Server

"FreePBX GUI - > Admin → Backup & Restore → Global Settings" has server SSH keys which we can copy to Secondary server manually. (note some browsers may not let you copy this data)

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You may copy this key to spare/Secondary server manually to /root/.ssh/authorized_keys file. Create a file called "authorized_keys" (if not present) and add your Public Key in that file. If that file already exists just add your Key to the end of the file (make sure each key is separated by a new line!)

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2. Using SSH CLI command to copy Primary SSH keys to Secondary server (preferred method)

Login to your Primary server with an SSH client such as PuTTy, SecureCRT, or other SSH client.

We will copy the key to the Secondary server with the help of  the following command so that the primary server can SSH to the secondary server without needing a password.  

At the primary server Linux CLI prompt type: sudo -u asterisk ssh-copy-id -i  /home/asterisk/.ssh/id_rsa.pub root@SecondaryServerIP and enter the password when prompted. 

If this command completes without error, you are ready to test:

At the prompt type: ssh -i /home/asterisk/.ssh/id_rsa root@SecondaryServerIP
If all went well, you should now be logged in to the Secondary server.

Filestore Module Setup 

Once SSH Setup done, we have to configure the Filestore module for the SSH.

Please follow the guide Filestore Module#SSH to perform the SSH configuration on the primary server.

FTP Configuration 

We have to enable FTP protocol on the Warm Spare (Secondary) server by following System Admin - Provisioning Protocols#ProvisioningProtocols-Enable/DisableFTP 

Filestore Module Setup 

Once FTP Setup as mentioned as above done then we have to configure "Filestore" module for the FTP.

Please follow the guide Filestore Module#FTP to perform the FTP configuration i.e. Add Warm Spare (Secondary) server.

Generating API Credentials on the Warm Spare Server

We need to generate API credentials on Warm Spare (Secondary) server which will be used by Primary Server to trigger the "restore" process to Warm Spare server.
SSH or FTP method will be used to copy the data but API will be used to initiate the "restore" process.
Please follow the steps below to generate the Warm spare API credentials which will be used later in within the backup job definition on the primary.

FreePBX GUI → Connectivity → API 

1. Create the Application Machine to Machine App

2. Allow the scope(gql:backup) to access the backup module and then "Add Application".

    

    

3. Copy the Access details to notepad or text editor, you will need this info when we setup the replication job on the Primary server.

    

    

How to setup a Warm Spare Backup job

Build your backup job as you normally would however make sure you are adding your Warm Spare server as one of the backup Storage Locations (note you can select multiple Storage Locations here)

Enable the "Warm Spare" option.

Once we enable the "Warm spare" option. Now you can see the Warmspare configuration options as shown below.

Warm Spare Server Input fields

Execute Warm spare job 

Once the warm spare backup job has been created, we can see the backup job in Backup & Restore grid.

We can either choose to run Warm Spare via "Scheduling option" while creating or editing backup job or we can run directly from the grid.

Warm spare job output will be something like below and at the end "Restore Status" will display the response from the API (which triggered the restore process in warm spare server).