Last active
January 29, 2024 23:00
-
-
Save innovia/fbba8259042f71db98ea8d4ad19bd708 to your computer and use it in GitHub Desktop.
Create a service account and generate a kubeconfig file for it - this will also set the default namespace for the user
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#!/bin/bash | |
set -e | |
set -o pipefail | |
# Add user to k8s using service account, no RBAC (must create RBAC after this script) | |
if [[ -z "$1" ]] || [[ -z "$2" ]]; then | |
echo "usage: $0 <service_account_name> <namespace>" | |
exit 1 | |
fi | |
SERVICE_ACCOUNT_NAME=$1 | |
NAMESPACE="$2" | |
KUBECFG_FILE_NAME="/tmp/kube/k8s-${SERVICE_ACCOUNT_NAME}-${NAMESPACE}-conf" | |
TARGET_FOLDER="/tmp/kube" | |
create_target_folder() { | |
echo -n "Creating target directory to hold files in ${TARGET_FOLDER}..." | |
mkdir -p "${TARGET_FOLDER}" | |
printf "done" | |
} | |
create_service_account() { | |
echo -e "\\nCreating a service account in ${NAMESPACE} namespace: ${SERVICE_ACCOUNT_NAME}" | |
kubectl create sa "${SERVICE_ACCOUNT_NAME}" --namespace "${NAMESPACE}" | |
} | |
get_secret_name_from_service_account() { | |
echo -e "\\nGetting secret of service account ${SERVICE_ACCOUNT_NAME} on ${NAMESPACE}" | |
SECRET_NAME=$(kubectl get sa "${SERVICE_ACCOUNT_NAME}" --namespace="${NAMESPACE}" -o json | jq -r .secrets[].name) | |
echo "Secret name: ${SECRET_NAME}" | |
} | |
extract_ca_crt_from_secret() { | |
echo -e -n "\\nExtracting ca.crt from secret..." | |
kubectl get secret --namespace "${NAMESPACE}" "${SECRET_NAME}" -o json | jq \ | |
-r '.data["ca.crt"]' | base64 -D > "${TARGET_FOLDER}/ca.crt" | |
printf "done" | |
} | |
get_user_token_from_secret() { | |
echo -e -n "\\nGetting user token from secret..." | |
USER_TOKEN=$(kubectl get secret --namespace "${NAMESPACE}" "${SECRET_NAME}" -o json | jq -r '.data["token"]' | base64 -D) | |
printf "done" | |
} | |
set_kube_config_values() { | |
context=$(kubectl config current-context) | |
echo -e "\\nSetting current context to: $context" | |
CLUSTER_NAME=$(kubectl config get-contexts "$context" | awk '{print $3}' | tail -n 1) | |
echo "Cluster name: ${CLUSTER_NAME}" | |
ENDPOINT=$(kubectl config view \ | |
-o jsonpath="{.clusters[?(@.name == \"${CLUSTER_NAME}\")].cluster.server}") | |
echo "Endpoint: ${ENDPOINT}" | |
# Set up the config | |
echo -e "\\nPreparing k8s-${SERVICE_ACCOUNT_NAME}-${NAMESPACE}-conf" | |
echo -n "Setting a cluster entry in kubeconfig..." | |
kubectl config set-cluster "${CLUSTER_NAME}" \ | |
--kubeconfig="${KUBECFG_FILE_NAME}" \ | |
--server="${ENDPOINT}" \ | |
--certificate-authority="${TARGET_FOLDER}/ca.crt" \ | |
--embed-certs=true | |
echo -n "Setting token credentials entry in kubeconfig..." | |
kubectl config set-credentials \ | |
"${SERVICE_ACCOUNT_NAME}-${NAMESPACE}-${CLUSTER_NAME}" \ | |
--kubeconfig="${KUBECFG_FILE_NAME}" \ | |
--token="${USER_TOKEN}" | |
echo -n "Setting a context entry in kubeconfig..." | |
kubectl config set-context \ | |
"${SERVICE_ACCOUNT_NAME}-${NAMESPACE}-${CLUSTER_NAME}" \ | |
--kubeconfig="${KUBECFG_FILE_NAME}" \ | |
--cluster="${CLUSTER_NAME}" \ | |
--user="${SERVICE_ACCOUNT_NAME}-${NAMESPACE}-${CLUSTER_NAME}" \ | |
--namespace="${NAMESPACE}" | |
echo -n "Setting the current-context in the kubeconfig file..." | |
kubectl config use-context "${SERVICE_ACCOUNT_NAME}-${NAMESPACE}-${CLUSTER_NAME}" \ | |
--kubeconfig="${KUBECFG_FILE_NAME}" | |
} | |
create_target_folder | |
create_service_account | |
get_secret_name_from_service_account | |
extract_ca_crt_from_secret | |
get_user_token_from_secret | |
set_kube_config_values | |
echo -e "\\nAll done! Test with:" | |
echo "KUBECONFIG=${KUBECFG_FILE_NAME} kubectl get pods" | |
echo "you should not have any permissions by default - you have just created the authentication part" | |
echo "You will need to create RBAC permissions" | |
KUBECONFIG=${KUBECFG_FILE_NAME} kubectl get pods |
Does this have an effect on the process?
From https://kubernetes.io/docs/concepts/security/service-accounts/
"""
Service Account Token Secrets In Kubernetes v1.24 and later, the LegacyServiceAccountTokenNoAutoGeneration feature gate prevents Kubernetes from automatically creating these tokens for ServiceAccounts. LegacyServiceAccountTokenNoAutoGeneration is enabled by default; in other words, Kubernetes does not create these tokens.
"""
Here is an updated version which creates the api token manually.
https://gist.github.com/sdarwin/ffc5fed82b6128a7549fd6d5696d98a8
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Ah - this fixed it. Thanks!