This type of installation is used for switch users to new version in one moment (kubernetes RollingUpdate strategy can simultaneously routing requests to new and to old version)

You need kubernetes cluster v1.20+ with helm v3.4.2+ and Ingress

For example use host name http-echo.cluster-test.com

install application version v1

helm upgrade --install helm-blue-green \
--namespace helm-blue-green \
--set host=http-echo.cluster-test.com \
--set version=v1 \
chart/helm-blue-green

run command to test

while true; do curl -sS http-echo.cluster-test.com ; sleep 0.1; done

update application to version v2

helm upgrade --install helm-blue-green \
--namespace helm-blue-green \
--set host=http-echo.cluster-test.com \
--set version=v2 \
chart/helm-blue-green

update application to version v3

helm upgrade --install helm-blue-green \
--namespace helm-blue-green \
--set host=http-echo.cluster-test.com \
--set version=v3 \
chart/helm-blue-green

helm delete --purge helm-blue-green
kubectl delete ns helm-blue-green

• helm rollback doesn't work, version deployments is created by kubernetes job - helm can rollback only objects that was installed only by helm - for rollback - you need install requred version