Developing a variable strategy

Our objective is to create GKE clusters for multiple independent environments. In our example, we provision two environments – development and production. However, we want to keep it flexible enough to provide additional environments, such as testing or staging, when required. We also want to balance flexibility with ease of use. For this, we need to decide on a variable strategy. First, we must determine which values might differ from environment to environment and which should remain the same regardless of the environment. For example, we know we want to have different values for the node pool configurations, such as the initial and maximum number of nodes, but cluster configuration attributes such as network policy and HTTP load balancing are the same regardless of the environment. Thus, we need to define variables for the node pools but not for cluster configurations.

Second, we must decide which variables to make optional and which ones...