June 2022

I attempted to retrieve the source global IP address from HTTP requests through Kubernetes Ingress, but I ended up obtaining the IP address of Kubernetes' local network, which did not work as intended. After switching Kubernetes to MicroK8s and using its built-in Ingress controller, I was able to successfully retrieve the global remote IP address. This is a note on that experience.

When using MicroK8s on a server, a separate image repository for ctr is created apart from the server's Docker image repository. Since MicroK8s uses this ctr, Docker-loaded images cannot be used directly. It is necessary to import the images using `microk8s ctr image import`.

In the latest version of Kubernetes (around 1.25?), "apiVersion: extensions/v1beta1" is no longer supported. If you have written Ingress configurations using "extensions/v1beta1", applying them with "kubectl apply" will result in the error: error: unable to recognize "ingress.yml": no matches for kind "Ingress" in version "extensions/v1beta1" To resolve this issue, you need to update the "apiVersion" to "networking.k8s.io/v1".

When trying to use the `docker run` command with SSH arguments and encountering the message "ssh docker run the input device is not a TTY," you can resolve the issue by adding the `-t` option to the SSH command.