Files
capsule/hack/create-user.sh
maxgio e0d5e6feb2 Refactor helper script to create a Capsule user (#454)
* chore(hack/create-user.sh): let pick bash interpreter from path

bash interpreter binary could be put at different paths than /bin/bash.

Signed-off-by: maxgio92 <massimiliano.giovagnoli.1992@gmail.com>

* refactor(hack/create-user.sh): add helper function to apply dry

add helper function to check commands existence.

Signed-off-by: maxgio92 <massimiliano.giovagnoli.1992@gmail.com>
2021-10-22 20:55:52 +02:00

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#!/usr/bin/env bash
# This script uses Kubernetes CertificateSigningRequest (CSR) to generate a
# certificate signed by the Kubernetes CA itself.
# It requires cluster admin permission.
#
# e.g.: ./create-user.sh alice oil
# where `oil` is the Tenant and `alice` the owner
# Exit immediately if a command exits with a non-zero status.
set -e
function check_command() {
local command=$1
if ! command -v $command &> /dev/null; then
echo "Error: ${command} not found"
exit 1
fi
}
check_command openssl
check_command kubectl
check_command jq
USER=$1
TENANT=$2
GROUP=$3
if [[ -z ${USER} ]]; then
echo "User has not been specified!"
exit 1
fi
if [[ -z ${TENANT} ]]; then
echo "Tenant has not been specified!"
exit 1
fi
if [[ -z ${GROUP} ]]; then
GROUP=capsule.clastix.io
fi
TMPDIR=$(mktemp -d)
echo "creating certs in TMPDIR ${TMPDIR} "
MERGED_GROUPS=$(echo "/O=$GROUP" | sed "s/,/\/O=/g")
echo "merging groups ${MERGED_GROUPS}"
openssl genrsa -out ${USER}-${TENANT}.key 2048
openssl req -new -key ${USER}-${TENANT}.key -subj "/CN=${USER}${MERGED_GROUPS}" -out ${TMPDIR}/${USER}-${TENANT}.csr
# Clean any previously created CSR for the same user.
kubectl delete csr ${USER}-${TENANT} 2>/dev/null || true
#
# Create a new CSR file.
#
if [ $(kubectl version -o json | jq -r .serverVersion.minor) -gt 19 ]; then
cat <<EOF > ${TMPDIR}/${USER}-${TENANT}-csr.yaml
apiVersion: certificates.k8s.io/v1
kind: CertificateSigningRequest
metadata:
name: ${USER}-${TENANT}
spec:
signerName: kubernetes.io/kube-apiserver-client
groups:
- system:authenticated
request: $(cat ${TMPDIR}/${USER}-${TENANT}.csr | base64 | tr -d '\n')
usages:
- digital signature
- key encipherment
- client auth
EOF
else
cat <<EOF > ${TMPDIR}/${USER}-${TENANT}-csr.yaml
apiVersion: certificates.k8s.io/v1beta1
kind: CertificateSigningRequest
metadata:
name: ${USER}-${TENANT}
spec:
groups:
- system:authenticated
request: $(cat ${TMPDIR}/${USER}-${TENANT}.csr | base64 | tr -d '\n')
usages:
- digital signature
- key encipherment
- client auth
EOF
fi
# Create the CSR
kubectl apply -f ${TMPDIR}/${USER}-${TENANT}-csr.yaml
# Approve and fetch the signed certificate
kubectl certificate approve ${USER}-${TENANT}
kubectl get csr ${USER}-${TENANT} -o jsonpath='{.status.certificate}' | base64 --decode > ${USER}-${TENANT}.crt
# Create the kubeconfig file
CONTEXT=$(kubectl config current-context)
CLUSTER=$(kubectl config view -o jsonpath="{.contexts[?(@.name == \"$CONTEXT\"})].context.cluster}")
SERVER=$(kubectl config view -o jsonpath="{.clusters[?(@.name == \"${CLUSTER}\"})].cluster.server}")
CA=$(kubectl config view --flatten -o jsonpath="{.clusters[?(@.name == \"${CLUSTER}\"})].cluster.certificate-authority-data}")
cat > ${USER}-${TENANT}.kubeconfig <<EOF
apiVersion: v1
clusters:
- cluster:
certificate-authority-data: $CA
server: ${SERVER}
name: ${CLUSTER}
contexts:
- context:
cluster: ${CLUSTER}
user: ${USER}
name: ${USER}-${TENANT}
current-context: ${USER}-${TENANT}
kind: Config
preferences: {}
users:
- name: ${USER}
user:
client-certificate: ${USER}-${TENANT}.crt
client-key: ${USER}-${TENANT}.key
EOF
echo "kubeconfig file is:" ${USER}-${TENANT}.kubeconfig
echo "to use it as" ${USER} "export KUBECONFIG="${USER}-${TENANT}.kubeconfig