Hands-On Microservices with Kubernetes

Hybrid configuration and defaults

So far, we have reviewed the primary configuration mechanisms:

• Convention over configuration
• Command-line arguments
• Environment variables
• Configuration files

These mechanisms are not mutually exclusive. Many applications will support some and even all of them. Very often, there will be a configuration resolution mechanism where a configuration file has a standard name and location, but you will still be able to specify a different configuration file via an environment variable and override even that for a specific run using a command-line argument. You don't have to look very far. Kubectl is a program that looks for its configuration file in $HOME/.kube by default; you can specify a different file via the ...