#!/bin/bash
# Creates a restricted kubeconfig for the oil-calculator namespace only.
# Run on the k8s server as a user with cluster-admin access.
set -e

NAMESPACE=oil-calculator
SA_NAME=oil-calculator-deployer

echo "Creating ServiceAccount, Role, and RoleBinding..."

kubectl apply -f - <<EOF
apiVersion: v1
kind: ServiceAccount
metadata:
  name: ${SA_NAME}
  namespace: ${NAMESPACE}
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: ${SA_NAME}-role
  namespace: ${NAMESPACE}
rules:
  - apiGroups: ["", "apps", "networking.k8s.io"]
    resources: ["pods", "services", "deployments", "replicasets", "ingresses", "persistentvolumeclaims", "configmaps", "secrets", "pods/log"]
    verbs: ["get", "list", "watch", "create", "update", "patch", "delete"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: ${SA_NAME}-binding
  namespace: ${NAMESPACE}
subjects:
  - kind: ServiceAccount
    name: ${SA_NAME}
    namespace: ${NAMESPACE}
roleRef:
  kind: Role
  name: ${SA_NAME}-role
  apiGroup: rbac.authorization.k8s.io
---
apiVersion: v1
kind: Secret
metadata:
  name: ${SA_NAME}-token
  namespace: ${NAMESPACE}
  annotations:
    kubernetes.io/service-account.name: ${SA_NAME}
type: kubernetes.io/service-account-token
EOF

echo "Waiting for token..."
sleep 3

# Get cluster info
CLUSTER_SERVER=$(kubectl config view --minify -o jsonpath='{.clusters[0].cluster.server}')
CLUSTER_CA=$(kubectl config view --raw --minify -o jsonpath='{.clusters[0].cluster.certificate-authority-data}')
TOKEN=$(kubectl get secret ${SA_NAME}-token -n ${NAMESPACE} -o jsonpath='{.data.token}' | base64 -d)

cat > kubeconfig <<EOF
apiVersion: v1
kind: Config
clusters:
  - cluster:
      certificate-authority-data: ${CLUSTER_CA}
      server: ${CLUSTER_SERVER}
    name: oil-calculator
contexts:
  - context:
      cluster: oil-calculator
      namespace: ${NAMESPACE}
      user: ${SA_NAME}
    name: oil-calculator
current-context: oil-calculator
users:
  - name: ${SA_NAME}
    user:
      token: ${TOKEN}
EOF

echo "Kubeconfig written to ./kubeconfig"
echo "Test with: KUBECONFIG=./kubeconfig kubectl get pods"