bootstrap.py

import subprocess
import json

def check_docker_bin():
    """
        Package: docker
    """
    try:
        r = subprocess.run(["docker", "version", "-f", "json"], check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
    except subprocess.CalledProcessError:
        return ("Unable to access Docker Binary")

    return ("Docker version:", json.loads(r.stdout)['Client']['Version'])

def check_kubectl_bin():
    """
        Download URL: https://kubernetes.io/docs/tasks/tools/install-kubectl-linux/#install-kubectl-binary-with-curl-on-linux
        Download cURL: curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
    """
    try:
        r = subprocess.run(["kubectl", "version", "-o", "json", "--client=true"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
    except subprocess.CalledProcessError:
        return ("Unable to access kubectl Binary")

    return ("Kubectl version:", json.loads(r.stdout)['clientVersion']['gitVersion'])


def check_git_bin():
    """
        Package: git
    """
    try:
        r = subprocess.run(["git", "version"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
    except subprocess.CalledProcessError:
        return ("Unable to access git Binary")

    return ("Git version:", r.stdout.split(" ")[2].rstrip("\n"))

def check_kind_bin():
    """
        Download URL: https://kind.sigs.k8s.io/docs/user/quick-start/#installing-with-a-package-manager
        Download cURL: [ $(uname -m) = x86_64 ] && curl -Lo ./kind https://kind.sigs.k8s.io/dl/v0.26.0/kind-linux-amd64
    """
    try:
        r = subprocess.run(["kind", "version"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
    except subprocess.CalledProcessError:
        return ("Unable to access kind Binary")

    return ("Kind version:", r.stdout.split(" ")[1])

def check_bins():
    check_docker_bin()
    check_kubectl_bin()
    check_git_bin()
    check_kind_bin()

def check_kind_clusters():
    r = subprocess.run(["kind", "get", "clusters"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
    if r.stderr.rstrip('\n') == "No kind clusters found.":
        return create_kind_cluster()
    else:
        return ("Kind cluster already exists:", r.stdout.rstrip('\n'))

def create_kind_cluster():
    try:
        r = subprocess.run(["kind", "create", "cluster", "--config", "kind-config.yaml"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
    except subprocess.CalledProcessError:
        return ("Unable to create the kind cluster")

    return ("Kind cluster 'local' created")

def configure_kubectl_context():
    try:
        r = subprocess.run(["kubectl", "config", "use-context", "kind-local"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
    except subprocess.CalledProcessError:
        return ("Unable to update kubectl current context")

    return ("kubectl config use-context kind-local ran successfully.")

def check_kind_access():
    try:
        r = subprocess.run(["kubectl", "get", "nodes", "-o", "json"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
    except subprocess.CalledProcessError:
        return ("Unable to connect to local kind cluster")

    return ("Successfully contact local kind control-plane, total number of nodes:", len(json.loads(r.stdout)["items"]))

if __name__ == "__main__":
    check_kind_clusters()
    configure_kubectl_context()
    print(check_kind_access())

kind-config.yaml

kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
name: local
nodes:
- role: control-plane
- role: worker
  labels:
    app: backend
- role: worker
  labels:
    app: backend
- role: worker
  labels:
    app: frontend
- role: worker
  labels:
    app: frontend
- role: worker
  labels:
    app: db
- role: worker
  labels:
    app: db