3.5. Bootstrap certificates
3.5.1. Purpose
The kubelet, in OpenShift Container Platform 4 and later, uses the bootstrap certificate located in /etc/kubernetes/kubeconfig
to initially bootstrap. This is followed by the bootstrap initialization process and authorization of the kubelet to create a CSR.
In that process, the kubelet generates a CSR while communicating over the bootstrap channel. The controller manager signs the CSR, resulting in a certificate that the kubelet manages.
3.5.2. Management
These certificates are managed by the system and not the user.
3.5.3. Expiration
This bootstrap CA is valid for 10 years.
The kubelet-managed certificate is valid for one year and rotates automatically at around the 80 percent mark of that one year.
3.5.4. Customization
You cannot customize the bootstrap certificates.