Tried the above but didn’t work . I m using istio-1.5.2 . Later tried by running the below , where /tmp/gate is the istio operatior definition of gateway . chnaged the count there . It ran successfully
istioctl manifest apply --set values.pilot.autoscaleMin=4 --set values.gateways.istio-ingressgateway.type=NodePort --set values.prometheus.hub=abc.com --set values.global.hub=abc.com -f /tmp/gate -f /tmp/pilot .
As you see above i used --set directive as well as the -f for istio operator . During upgrade istio doc say
istioctl upgrade -f
<your-custom-configuration-file> is the IstioOperator API Configuration file you used to customize the installation of the currently-running version of Istio.
istioctl upgrade does not support the
--set flag. Therefore, if you installed Istio using the
--set command, create a configuration file with the equivalent configuration options and pass it to the
istioctl upgrade command using the
-f flag instead.
Now if i generate the manifest of the command i ran above which is combination of -f and --set .
The upgrade gives error
Error: failed to generate IOPS from file [/tmp/istio-release], error: could not overlay user config over base: json merge error (Invalid JSON Patch) for base object:
So wondering , istio installtion should only be done using either --set (helm thingy ) OR by chaning the istio api operator as combination seems to give error . this is critcal as it might halt future upgrade