#!/bin/bash

echo "## Check Expiration before renewal ##"

{{ bin_dir }}/kubeadm certs check-expiration

days_buffer=7 # set a time margin, because we should not renew at the last moment
# systemctl show reports an empty NextElapseUSecRealtime while the timer's unit is
# running, so use the calendar spec to get the next scheduled run.
next_time=$(LC_ALL=C systemd-analyze calendar "{{ auto_renew_certificates_systemd_calendar }}" | grep -oP 'Next elapse:\s*\K.*\S')

if [ "${next_time}" == "" ] || [ "${next_time}" == "never" ]; then
	echo "## Skip expiry comparison due to fail to parse next elapse from systemd calendar,do renewal directly ##"
else
	current_time=$(date +%s)
	target_time=$(date -d "${next_time} + ${days_buffer} days" +%s) # $next_time - $days_buffer days
	expiry_threshold=$(( ${target_time} - ${current_time} ))
	# super-admin.conf only exists on the node where "kubeadm init" ran, the other
	# control plane nodes see it as missing (residualTime 0). Don't let missing
	# certs force a renewal here, kubeadm can't renew them anyway.
	expired_certs=$({{ bin_dir }}/kubeadm certs check-expiration -o jsonpath="{range .certificates[?(@.residualTime<${expiry_threshold}.0)]}{.name}={.missing}{\"\n\"}{end}" | sed -n 's/=false$//p')
    if [ "${expired_certs}" == "" ];then
		echo "## Skip cert renew and K8S container restart, since all residualTimes are beyond threshold ##"
		exit 0
	fi
	echo "## Certificates to renew: ##"
	echo "${expired_certs}"
fi

echo "## Renewing certificates managed by kubeadm ##"
{{ bin_dir }}/kubeadm certs renew all

echo "## Restarting control plane pods managed by kubeadm ##"
{% if container_manager == "docker" %}
{{ docker_bin_dir }}/docker ps -af 'name=k8s_POD_(kube-apiserver|kube-controller-manager|kube-scheduler|etcd)-*' -q | /usr/bin/xargs {{ docker_bin_dir }}/docker rm -f
{% else %}
{{ bin_dir }}/crictl pods --namespace kube-system --name 'kube-scheduler-*|kube-controller-manager-*|kube-apiserver-*|etcd-*' -q | /usr/bin/xargs {{ bin_dir }}/crictl rmp -f
{% endif %}

echo "## Updating /root/.kube/config ##"
cp {{ kube_config_dir }}/admin.conf /root/.kube/config

echo "## Waiting for apiserver to be up again ##"
until printf "" 2>>/dev/null >>/dev/tcp/127.0.0.1/{{ kube_apiserver_port | default(6443) }}; do sleep 1; done

echo "## Expiration after renewal ##"
{{ bin_dir }}/kubeadm certs check-expiration