I have multiple public and private applications running in my kubernetes cluster. I want to separate out traffic for each type by running multiple istio-gateway deployments. Is there any straight methods to implement it with istio.
For both type of application I am using custom CA and importing certificates as secret manually. Do I need to anything cert manager part to achieve my use case
The cert-manager is not required to achieve this configuration.
To install custom istio-ingress-gateway (for you private domain) next to the default one (for public domain), you can take as an example 'example-values/values-istio-gateways.yaml' values file (part of official Istio github project), and use it with helm, to generate all necessary manifest files to upgrade/extend your current Istio installation.
To generate manifest files use the following command:
helm template install/kubernetes/helm/istio --set gateways.custom-gateway.namespace=nepomucen-custom -f install/kubernetes/istio-demo.yaml -f install/kubernetes/helm/istio/example-values/values-istio-gateways.yaml
Note: This creates custom gateway in non-default namespace