k8s kustomization generate from kubectl

gen_kustomization.sh

#!/usr/bin/env bash
#==============================================================================
# title: gen_kustomization.sh
# description: This script automatically creates kustomization deployment files from kubectl
# author: Kawin Viriyaprasopsook <kawin.v@kkumail.com>
# usage: bash gen_kustomization.sh
# notes: need `kubectl kubectl-convert kubectl-neat` packages
#==============================================================================

mkdir -p kustomization && cd kustomization

# Get all namespaces except system, cattle, and kube
namespaces=$(kubectl get namespaces -o custom-columns=:metadata.name --no-headers | grep -E -v '^(system|cattle|kube)')

# Loop through each namespace
for namespace in $namespaces; do
    echo "Namespace: $namespace"

    # Create a directory for the namespace
    mkdir -p "$namespace"

    # Export the namespace's resources to YAML files
    # kubectl get project "$namespace" -o yaml | kubectl convert -f - | kubectl neat -f - >"$namespace/project.yaml"
    kubectl get namespace "$namespace" -o yaml | kubectl convert -f - | kubectl neat -f - >"$namespace/namespace.yaml"
    kubectl get deployment -n "$namespace" -o yaml | kubectl convert -f - | kubectl neat -f - >"$namespace/deployment.yaml"
    kubectl get service -n "$namespace" -o yaml | kubectl convert -f - | kubectl neat -f - >"$namespace/service.yaml"
    kubectl get ingress -n "$namespace" -o yaml | kubectl convert -f - | kubectl neat -f - >"$namespace/ingress.yaml"
    kubectl get HorizontalPodAutoscaler -n "$namespace" -o yaml | kubectl convert -f - | kubectl neat -f - >"$namespace/HorizontalPodAutoscaler.yaml"
    kubectl get ServiceEntry -n "$namespace" -o yaml | kubectl neat -f - >"$namespace/ServiceEntry.yaml"

    # Enable Istio auto injection at deploy time
    if grep -q 'istio-injection' "$namespace/namespace.yaml"; then
      echo "Already istio-injection, skipping..."
    else
      sed -i '/labels:/a \      istio-injection: enabled' "$namespace/namespace.yaml"
    fi

    # Clean up externalIP, clusterIP, and publicEndpoints endpoints for deployment on a different cluster
    sed -i '/externalIPs:/d' "$namespace/"*.yaml
    sed -i '/clusterIP:/d' "$namespace/"*.yaml
    sed -i '/publicEndpoints:/d' "$namespace/"*.yaml

    # Create a kustomization.yaml file for the namespace
    cat <<EOL >$namespace/kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: $namespace

resources:
# - project.yaml
- namespace.yaml
- deployment.yaml
- service.yaml
- ingress.yaml
- HorizontalPodAutoscaler.yaml
- ServiceEntry.yaml
EOL

done

cd ..

exit 0