Does blue green deployment need two regions in aro?

No, blue-green deployment in Azure Red Hat OpenShift (ARO) does not require two separate regions. It typically involves having two separate environments (or versions) within the same cluster or namespace. Blue-green deployments work by maintaining two versions of an application—one being the active (blue) and the other being the idle or testing version (green).

In the context of ARO, this can be achieved using separate namespaces, deployments, or even routes within the same cluster and region. Here’s how blue-green deployments work in ARO:

1. Single Cluster, Single Namespace: You can deploy both the blue (current) and green (new) versions of the application within the same namespace. This is done using separate deployments and services for each version.

2. Single Cluster, Separate Namespaces: Use two separate namespaces for each version of the application within the same ARO cluster. This keeps resources more isolated.

3. Traffic Routing and Switching: With OpenShift's native routing features (like OpenShift Routes), you can control traffic between the blue and green environments. When the green version is ready, you switch the traffic to it, making it the new active version.

If you wanted to distribute your blue-green deployments across different regions for high availability or disaster recovery, that would involve setting up multiple clusters in different regions. However, for a standard blue-green deployment in ARO, two regions are not a requirement.