DP API Options

README.md

Assumption:

• We want to support a range of devices
• We acknowledge that certain devices are exposed using different kernel APIs (paths, netlink, …)
• We acknowledge that a logical/physical device can consist of multiple kernel level objects (paths, netlinks, …)
• We acknowledge that device plugins could require informations about the pod in order to provide the right resource.

Goal:

• Keep the declarative approach
• iow: DP creates, kubelet allocates
• iow: Prevent side-kubelet

explicit.proto

// FilesystemDevice is representing a device which shall be allocated to a 
// container using a file-system path.
// Is equal to the previous DeviceSpec definition.
message FilesystemDevice {
    // Path of the device within the container.
    string container_path = 1;
    // Path of the device on the host.
    string host_path = 2;
    // Cgroups permissions of the device, candidates are one or more of
    // * r - allows container to read from the specified device.
    // * w - allows container to write to the specified device.
    // * m - allows container to create device files that do not yet exist.
    string permissions = 3;
}
 
// NetlinkDevice is representing a device which shall be allocated to a pod
// as network interface (via the netlink API).
message NetlinkDevice {
    // FIXME we need to understand how to pass a namespace with pb
    string netNS = 1;
    string interfacename = 2;
}
 
// PciDevice is representing a device which shall be allocated to a container
// as a PCI device. For a container runtime this could mean exposing the sysfs 
// path. For a hypervisor runtime, this could mean exposing it using PCI 
// passthrough mode.
message PciDevice {
    string vendorid = 1;
    string productid = 2;
}
 
// DeviceSpec specifies a host device to be allocated into a container or pod.
message DeviceSpec {
    oneof cls {
                FilesystemDevice fs;
                NetlinkDevice ifname;
                PciDevice pci;
        }
}

// Examples

kapi.proto

// DeviceSpec specifies a host device to mount into a container.
message DeviceSpec {
    // Path of the device within the container.
    string identifier_container = 1;
    // Path of the device on the host.
    string identifier_host = 2;
    // Cgroups permissions of the device, candidates are one or more of
    // * r - allows container to read from the specified device.
    // * w - allows container to write to the specified device.
    // * m - allows container to create device files that do not yet exist.
    string permissions = 3;
    // Define the type of 
    enum ApiType {
        PATH = 1;
        NETLINK = 2;
    }
    ApiType api_type = 4;
}

// Examples (cid, hid, api_type)
// ("/dev/gpu0", "/dev/gpu0", "path")
// ("eth42", "eth42", "netlink")
// ("/sys/class/fpga/intel-fpga-dev.1/intel-fpga-fme.1", …, "path")
// ("/sys/class/fpga/intel-fpga-dev.1/intel-fpga-port.2", …, "path")
// (/sys/class/fpga/intel-fpga-dev.1/intel-fpga-port.3, …, "path")

// Issues
// - Permissions does not apply to all types