How To Call Kubernetes API using Simple HTTP Client

There are plenty of reasons to call the Kubernetes API using a CLI (like curl) or GUI (like postman) HTTP client. For instance, you may need finer-grained control over Kubernetes Objects than kubectl provides or just want to explore the API before trying to access it from code.

This article is not a mere list of handy commands but a thoughtful walk-through revealing some interesting problems you may stumble upon while calling the Kubernetes API from the command line. It covers the following topics:

  • How to get the Kubernetes API server address
  • How to authenticate the API server to clients
  • How to authenticate clients to the API server using certificates
  • How to authenticate clients to the API server using tokens
  • Bonus: How to call the Kubernetes API from inside a Pod
  • How to perform the basic CRUD operations on Kubernetes Objects with curl
  • How to access the Kubernetes API directly using the kubectl's raw mode
  • Bonus: How to see what API requests a kubectl command like apply sends.

Happy reading!

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