Intel FPGA prestart CRI-O webhook for Kubernetes

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The FPGA CRI-O webhook is one of the components used to add support for Intel FPGA devices to Kubernetes.

The FPGA prestart CRI-O hook is triggered by container annotations, such as set by the FPGA device plugin. It performs discovery of the requested FPGA function bitstream and then programs FPGA devices based on the environment variables in the workload description.

The CRI-O prestart hook is only required when the FPGA admission webhook is configured for orchestration programmed mode, and is benign (un-used) otherwise.

Note: The fpga CRI-O webhook is usually installed by the same DaemonSet as the FPGA device plugin. If building and installing the CRI-O webhook by hand, it is recommended you reference the fpga plugin DaemonSet YAML for more details.


This component is one of a set of components that work together. You may also want to install the following:

All components have the same basic dependencies as the generic plugin framework dependencies

See the development guide for details if you want to deploy a customized version of the CRI hook.

Configuring CRI-O

Recent versions of CRI-O are shipped with default configuration file that prevents CRI-O to discover and configure hooks automatically. For FPGA orchestration programmed mode, the OCI hooks are the key component. Please ensure that your /etc/crio/crio.conf parameter hooks_dir is either unset (to enable default search paths for OCI hooks configuration) or contains the directory /etc/containers/oci/hooks.d.