Project: inftools-cn

Purpose: This repository contains a small helper container image and scripts to build and run a debugging/admin container for working with Docker and lightweight Kubernetes (k3d). The image includes kubectl, the Docker CLI, and k3d so you can create and administer a local k3d cluster from inside the container.

Key Files:

• Dockerfile: Builds the helper image (Debian Bookworm) with kubectl, k3d, and the Docker CLI.
• build.sh: Ensures the inftools-cn:latest image exists, creates a user Docker network (student-net) if missing, and (when needed) runs k3d cluster create mycluster inside the helper container. It also edits the kubeconfig stored in the mykube Docker volume so the cluster API uses the load-balancer node.
• run.sh: Launches an interactive shell in the helper container, mounting the Docker socket and the mykube volume.

Image / Resources:

• Image name: inftools-cn:latest
• Docker network used: student-net
• Docker volume used for kubeconfig: mykube

Requirements:

• Docker must be installed and the user must be able to access the Docker daemon (the scripts bind-mount /var/run/docker.sock).
• Host can run containers and create networks/volumes.

Quick Usage:

• Build and create the k3d cluster (recommended):

  ./build.sh
  

• Start an interactive shell inside the helper container (uses the pre-built inftools-cn:latest image):

  ./run.sh
  

see this demo of build.sh and run.sh on a debian bookworm OS

• Manual docker build/run (if you prefer):

  docker build -t inftools-cn:latest .
  docker network create student-net    # if not present
  docker run --rm -it --network student-net -v /var/run/docker.sock:/var/run/docker.sock -v mykube:/root/.kube inftools-cn:latest bash
  

What build.sh does (summary):

• Ensures the inftools-cn:latest image exists (builds it from Dockerfile if missing).
• Creates student-net Docker network if it doesn't exist.
• Runs the k3d cluster create mycluster command inside the helper container, captures the output to find the load-balancer node, and updates the kubeconfig in the mykube volume so the cluster API endpoint points to the LB node on port 6443.

Security notes:

• The container mounts the host Docker socket (/var/run/docker.sock) into the container which grants the container broad control over the host Docker daemon. Only run this in trusted environments.

License:

• This project is licensed under the GNU General Public License v3.0 (GPL-3.0).
• See the LICENSE file in this repository for the full license text.