docs: Document restricted annotations

Document restricted annotations, as implemented in
https://github.com/kata-containers/kata-containers/pull/902

Fixes: #1044
Forward-port-of: https://github.com/kata-containers/documentation/pull/755

Signed-off-by: Christophe de Dinechin <dinechin@redhat.com>
This commit is contained in:
Christophe de Dinechin 2020-10-27 15:57:27 +01:00
parent 1fc7b7641d
commit d67921a2af

View File

@ -3,6 +3,11 @@
Kata Containers gives users freedom to customize at per-pod level, by setting
a wide range of Kata specific annotations in the pod specification.
Some annotations may be [restricted](#restricted-annotations) by the
configuration file for security reasons, notably annotations that could lead the
runtime to execute programs on the host. Such annotations are marked with _(R)_ in
the tables below.
# Kata Configuration Annotations
There are several kinds of Kata configurations and they are listed below.
@ -40,6 +45,7 @@ There are several kinds of Kata configurations and they are listed below.
| `io.katacontainers.config.hypervisor.block_device_cache_set` | `boolean` | cache-related options will be set to block devices or not |
| `io.katacontainers.config.hypervisor.block_device_driver` | string | the driver to be used for block device, valid values are `virtio-blk`, `virtio-scsi`, `nvdimm`|
| `io.katacontainers.config.hypervisor.cpu_features` | `string` | Comma-separated list of CPU features to pass to the CPU (QEMU) |
| `io.katacontainers.config.hypervisor.ctlpath` (R) | `string` | Path to the `acrnctl` binary for the ACRN hypervisor |
| `io.katacontainers.config.hypervisor.default_max_vcpus` | uint32| the maximum number of vCPUs allocated for the VM by the hypervisor |
| `io.katacontainers.config.hypervisor.default_memory` | uint32| the memory assigned for a VM by the hypervisor in `MiB` |
| `io.katacontainers.config.hypervisor.default_vcpus` | uint32| the default vCPUs assigned for a VM by the hypervisor |
@ -55,7 +61,7 @@ There are several kinds of Kata configurations and they are listed below.
| `io.katacontainers.config.hypervisor.enable_vhost_user_store` | `boolean` | enable vhost-user storage device (QEMU) |
| `io.katacontainers.config.hypervisor.enable_virtio_mem` | `boolean` | enable virtio-mem (QEMU) |
| `io.katacontainers.config.hypervisor.entropy_source` | string| the path to a host source of entropy (`/dev/random`, `/dev/urandom` or real hardware RNG device) |
| `io.katacontainers.config.hypervisor.file_mem_backend` | string | file based memory backend root directory |
| `io.katacontainers.config.hypervisor.file_mem_backend` (R) | string | file based memory backend root directory |
| `io.katacontainers.config.hypervisor.firmware_hash` | string | container firmware SHA-512 hash value |
| `io.katacontainers.config.hypervisor.firmware` | string | the guest firmware that will run the container VM |
| `io.katacontainers.config.hypervisor.guest_hook_path` | string | the path within the VM that will be used for drop in hooks |
@ -66,7 +72,7 @@ There are several kinds of Kata configurations and they are listed below.
| `io.katacontainers.config.hypervisor.initrd_hash` | string | container guest initrd SHA-512 hash value |
| `io.katacontainers.config.hypervisor.initrd` | string | the guest initrd image that will run in the container VM |
| `io.katacontainers.config.hypervisor.jailer_hash` | string | container jailer SHA-512 hash value |
| `io.katacontainers.config.hypervisor.jailer_path` | string | the jailer that will constrain the container VM |
| `io.katacontainers.config.hypervisor.jailer_path` (R) | string | the jailer that will constrain the container VM |
| `io.katacontainers.config.hypervisor.kernel_hash` | string | container kernel image SHA-512 hash value |
| `io.katacontainers.config.hypervisor.kernel_params` | string | additional guest kernel parameters |
| `io.katacontainers.config.hypervisor.kernel` | string | the kernel used to boot the container VM |
@ -79,7 +85,7 @@ There are several kinds of Kata configurations and they are listed below.
| `io.katacontainers.config.hypervisor.pcie_root_port` | specify the number of PCIe Root Port devices. The PCIe Root Port device is used to hot-plug a PCIe device (QEMU) |
| `io.katacontainers.config.hypervisor.shared_fs` | string | the shared file system type, either `virtio-9p` or `virtio-fs` |
| `io.katacontainers.config.hypervisor.use_vsock` | `boolean` | specify use of `vsock` for agent communication |
| `io.katacontainers.config.hypervisor.vhost_user_store_path` | `string` | specify the directory path where vhost-user devices related folders, sockets and device nodes should be (QEMU) |
| `io.katacontainers.config.hypervisor.vhost_user_store_path` (R) | `string` | specify the directory path where vhost-user devices related folders, sockets and device nodes should be (QEMU) |
| `io.katacontainers.config.hypervisor.virtio_fs_cache_size` | uint32 | virtio-fs DAX cache size in `MiB` |
| `io.katacontainers.config.hypervisor.virtio_fs_cache` | string | the cache mode for virtio-fs, valid values are `always`, `auto` and `none` |
| `io.katacontainers.config.hypervisor.virtio_fs_daemon` | string | virtio-fs `vhost-user` daemon path |
@ -168,3 +174,31 @@ spec:
stdin: true
tty: true
```
# Restricted annotations
Some annotations are _restricted_, meaning that the configuration file specifies
the acceptable values. Currently, only hypervisor annotations are restricted,
for security reason, with the intent to control which binaries the Kata
Containers runtime will launch on your behalf.
The configuration file validates the annotation _name_ as well as the annotation
_value_.
The acceptable annotation names are defined by the `enable_annotations` entry in
the configuration file.
For restricted annotations, an additional configuration entry provides a list of
acceptable values. Since most restricted annotations are intended to control
which binaries the runtime can execute, the valid value is generally provided by
a shell pattern, as defined by `glob(3)`. The table below provides the name of
the configuration entry:
| Key | Config file entry | Comments |
|-------| ----- | ----- |
| `ctlpath` | `valid_ctlpaths` | Valid paths for `acrnctl` binary |
| `file_mem_backend` | `valid_file_mem_backends` | Valid locations for the file-based memory backend root directory |
| `jailer_path` | `valid_jailer_paths`| Valid paths for the jailer constraining the container VM (Firecracker) |
| `path` | `valid_hypervisor_paths` | Valid hypervisors to run the container VM |
| `vhost_user_store_path` | `valid_vhost_user_store_paths` | Valid paths for vhost-user related files|
| `virtio_fs_daemon` | `valid_virtio_fs_daemon_paths` | Valid paths for the `virtiofsd` daemon |