B #6765: Improve QEMU Guest Agent monitoring. (#3328)

* Improve qemu-ga monitoring resilience
* Add more commands to config files

Author: dann1

src/im_mad/remotes/kvm-probes.d/guestagent.conf

@@ -8,5 +8,16 @@
 # The value will be run as a command executed with virsh qemu-agent-command
 # The $vm_id substring, if existing, will be replaced by the VM ID when the monitoring probes
 # are looping on each of the VMs on the host. Each command will be run once per VM.
+# The expected response for each command is a JSON string with a "return" key.
+# The contents of it will appear on the MONITORING message from the poll probe.
 :commands:
-  :vm_qemu_ping: "one-$vm_id '{\"execute\":\"guest-ping\"}' --timeout 5"
+  :vm_qemu_ping: one-$vm_id '{"execute":"guest-ping"}' --timeout 5
+  # :guest_info: one-$vm_id '{"execute":"guest-info"}' --timeout 5
+  # # The first non-loopback address
+  # :vm_ip_address:       >
+  #                       one-$vm_id '{"execute":"guest-network-get-interfaces"}' --timeout 5 |
+  #                       jq '{"return": [.return[] | select(."ip-addresses") | ."ip-addresses"[] | select(."ip-address-type"=="ipv4" and (."ip-address"|startswith("127.")|not))."ip-address"][0]}'
+  # # Array of all IP addresses
+  # :vm_ip_address_list:  >
+  #                       one-$vm_id '{"execute":"guest-network-get-interfaces"}' --timeout 5 |
+  #                       jq '{"return" : [ .return[] | select(."ip-addresses") | ."ip-addresses"[]."ip-address" ]}'

src/im_mad/remotes/lib/kvm.rb

@@ -350,7 +350,16 @@ def ga_stats
                 if s.exitstatus != 0
                     @vm[ga_info] = e.chomp
                 else
-                    @vm[ga_info] = JSON.parse(text)['return']
+                    begin
+                        info = JSON.parse(text)['return']
+
+                        info = info.join(', ') if info.is_a?(Array)
+                        info = info.to_s.gsub(/["\[\]]/) { |match| "\\#{match}" } if info.is_a?(Hash)
+
+                        @vm[ga_info] = info
+                    rescue JSON::ParserError => e
+                        @vm[ga_info] = "Failed to parse command output: #{e}"
+                    end
                 end
             end
         else