# Node feature discovery for [Kubernetes](https://kubernetes.io) [![Build Status](https://api.travis-ci.org/kubernetes-sigs/node-feature-discovery.svg?branch=master)](https://travis-ci.org/kubernetes-sigs/node-feature-discovery) [![Go Report Card](https://goreportcard.com/badge/github.com/kubernetes-sigs/node-feature-discovery)](https://goreportcard.com/report/github.com/kubernetes-sigs/node-feature-discovery) - [Overview](#overview) - [Command line interface](#command-line-interface) - [Feature discovery](#feature-discovery) - [Feature sources](#feature-sources) - [Feature labels](#feature-labels) - [Getting started](#getting-started) - [System requirements](#system-requirements) - [Usage](#usage) - [Building from source](#building-from-source) - [Targeting nodes with specific features](#targeting-nodes-with-specific-features) - [References](#references) - [License](#license) - [Demo](#demo) ## Overview This software enables node feature discovery for Kubernetes. It detects hardware features available on each node in a Kubernetes cluster, and advertises those features using node labels. NFD consists of two software components: 1. **nfd-master** is responsible for labeling Kubernetes node objects 2. **nfd-worker** is detects features and communicates them to nfd-master. One instance of nfd-worker is supposed to be run on each node of the cluster ## Command line interface You can run NFD in stand-alone Docker containers e.g. for testing purposes. This is useful for checking features-detection. ### NFD-Master When running as a standalone container labeling is expected to fail because Kubernetes API is not available. Thus, it is recommended to use `--no-publish` command line flag. E.g. ``` $ docker run --rm --name=nfd-test nfd-master --no-publish 2019/02/01 14:48:21 Node Feature Discovery Master 2019/02/01 14:48:21 gRPC server serving on port: 8080 ``` Command line flags of nfd-master: ``` $ docker run --rm nfd-master --help ... nfd-master. Usage: nfd-master [--no-publish] [--label-whitelist=] [--port=] [--ca-file=] [--cert-file=] [--key-file=] [--verify-node-name] [--extra-label-ns=] nfd-master -h | --help nfd-master --version Options: -h --help Show this screen. --version Output version and exit. --port= Port on which to listen for connections. [Default: 8080] --ca-file= Root certificate for verifying connections [Default: ] --cert-file= Certificate used for authenticating connections [Default: ] --key-file= Private key matching --cert-file [Default: ] --verify-node-name Verify worker node name against CN from the TLS certificate. Only has effect when TLS authentication has been enabled. --no-publish Do not publish feature labels --label-whitelist= Regular expression to filter label names to publish to the Kubernetes API server. [Default: ] --extra-label-ns= Comma separated list of allowed extra label namespaces [Default: ] ``` ### NFD-Worker In order to run nfd-worker as a "stand-alone" container against your standalone nfd-master you need to run them in the same network namespace: ``` $ docker run --rm --network=container:nfd-test nfd-worker 2019/02/01 14:48:56 Node Feature Discovery Worker ... ``` If you just want to try out feature discovery without connecting to nfd-master, pass the `--no-publish` flag to nfd-worker. Command line flags of nfd-worker: ``` $ docker run --rm nfd-worker --help ... nfd-worker. Usage: nfd-worker [--no-publish] [--sources=] [--label-whitelist=] [--oneshot | --sleep-interval=] [--config=] [--options=] [--server=] [--server-name-override=] [--ca-file=] [--cert-file=] [--key-file=] nfd-worker -h | --help nfd-worker --version Options: -h --help Show this screen. --version Output version and exit. --config= Config file to use. [Default: /etc/kubernetes/node-feature-discovery/nfd-worker.conf] --options= Specify config options from command line. Config options are specified in the same format as in the config file (i.e. json or yaml). These options will override settings read from the config file. [Default: ] --ca-file= Root certificate for verifying connections [Default: ] --cert-file= Certificate used for authenticating connections [Default: ] --key-file= Private key matching --cert-file [Default: ] --server= NFD server address to connecto to. [Default: localhost:8080] --server-name-override= Name (CN) expect from server certificate, useful in testing [Default: ] --sources= Comma separated list of feature sources. [Default: cpu,iommu,kernel,local,memory,network,pci,storage,system] --no-publish Do not publish discovered features to the cluster-local Kubernetes API server. --label-whitelist= Regular expression to filter label names to publish to the Kubernetes API server. [Default: ] --oneshot Label once and exit. --sleep-interval= Time to sleep between re-labeling. Non-positive value implies no re-labeling (i.e. infinite sleep). [Default: 60s] ``` **NOTE** Some feature sources need certain directories and/or files from the host mounted inside the NFD container. Thus, you need to provide Docker with the correct `--volume` options in order for them to work correctly when run stand-alone directly with `docker run`. See the [template spec](https://github.com/kubernetes-sigs/node-feature-discovery/blob/master/nfd-worker-daemonset.yaml.template) for up-to-date information about the required volume mounts. ## Feature discovery ### Feature sources The current set of feature sources are the following: - CPU - IOMMU - Kernel - Memory - Network - PCI - Storage - System - Local (hooks for user-specific features) ### Feature labels The published node labels encode a few pieces of information: - Namespace, i.e. `feature.node.kubernetes.io` - The source for each label (e.g. `cpu`). - The name of the discovered feature as it appears in the underlying source, (e.g. `cpuid.AESNI` from cpu). - The value of the discovered feature. Feature label names adhere to the following pattern: ``` /-[.] ``` The last component (i.e. `attribute-name`) is optional, and only used if a feature logically has sub-hierarchy, e.g. `sriov.capable` and `sriov.configure` from the `network` source. ```json { "feature.node.kubernetes.io/cpu-": "true", "feature.node.kubernetes.io/iommu-": "true", "feature.node.kubernetes.io/kernel-": "", "feature.node.kubernetes.io/memory-": "true", "feature.node.kubernetes.io/network-": "true", "feature.node.kubernetes.io/pci-.present": "true", "feature.node.kubernetes.io/storage-": "true", "feature.node.kubernetes.io/system-": "", "feature.node.kubernetes.io/-": "" } ``` The `--sources` flag controls which sources to use for discovery. _Note: Consecutive runs of nfd-worker will update the labels on a given node. If features are not discovered on a consecutive run, the corresponding label will be removed. This includes any restrictions placed on the consecutive run, such as restricting discovered features with the --label-whitelist option._ ### CPU Features | Feature name | Attribute | Description | | ----------------------- | ------------------ | ----------------------------- | | cpuid | <cpuid flag> | CPU capability is supported | hardware_multithreading |
| Hardware multithreading, such as Intel HTT, enabled (number of locical CPUs is greater than physical CPUs) | power | sst_bf.enabled | Intel SST-BF ([Intel Speed Select Technology][intel-sst] - Base frequency) enabled | [pstate][intel-pstate] | turbo | Turbo frequencies are enabled in Intel pstate driver | [rdt][intel-rdt] | RDTMON | Intel RDT Monitoring Technology |
| RDTCMT | Intel Cache Monitoring (CMT) |
| RDTMBM | Intel Memory Bandwidth Monitoring (MBM) |
| RDTL3CA | Intel L3 Cache Allocation Technology |
| RDTL2CA | Intel L2 Cache Allocation Technology |
| RDTMBA | Intel Memory Bandwidth Allocation (MBA) Technology The (sub-)set of CPUID attributes to publish is configurable via the `attributeBlacklist` and `attributeWhitelist` cpuid options of the cpu source. If whitelist is specified, only whitelisted attributes will be published. With blacklist, only blacklisted attributes are filtered out. `attributeWhitelist` has priority over `attributeBlacklist`. For examples and more information about configurability, see [Configuration Options](#configuration-options). By default, the following CPUID flags have been blacklisted: BMI1, BMI2, CLMUL, CMOV, CX16, ERMS, F16C, HTT, LZCNT, MMX, MMXEXT, NX, POPCNT, RDRAND, RDSEED, RDTSCP, SGX, SSE, SSE2, SSE3, SSE4.1, SSE4.2 and SSSE3. **NOTE** The cpuid features advertise *supported* CPU capabilities, that is, a capability might be supported but not enabled. #### X86 CPUID Attributes (Partial List) | Attribute | Description | | --------- | ---------------------------------------------------------------- | | ADX | Multi-Precision Add-Carry Instruction Extensions (ADX) | AESNI | Advanced Encryption Standard (AES) New Instructions (AES-NI) | AVX | Advanced Vector Extensions (AVX) | AVX2 | Advanced Vector Extensions 2 (AVX2) #### Arm64 CPUID Attribute (Partial List) | Attribute | Description | | --------- | ---------------------------------------------------------------- | | AES | Announcing the Advanced Encryption Standard | EVSTRM | Event Stream Frequency Features | FPHP | Half Precision(16bit) Floating Point Data Processing Instructions | ASIMDHP | Half Precision(16bit) Asimd Data Processing Instructions | ATOMICS | Atomic Instructions to the A64 | ASIMRDM | Support for Rounding Double Multiply Add/Subtract | PMULL | Optional Cryptographic and CRC32 Instructions | JSCVT | Perform Conversion to Match Javascript | DCPOP | Persistent Memory Support ### IOMMU Features | Feature name | Description | | :------------: | :---------------------------------------------------------------------------------: | | enabled | IOMMU is present and enabled in the kernel ### Kernel Features | Feature | Attribute | Description | | ------- | ------------------- | -------------------------------------------- | | config | <option name> | Kernel config option is enabled (set 'y' or 'm').
Default options are `NO_HZ`, `NO_HZ_IDLE`, `NO_HZ_FULL` and `PREEMPT` | selinux | enabled | Selinux is enabled on the node | version | full | Full kernel version as reported by `/proc/sys/kernel/osrelease` (e.g. '4.5.6-7-g123abcde') |
| major | First component of the kernel version (e.g. '4') |
| minor | Second component of the kernel version (e.g. '5') |
| revision | Third component of the kernel version (e.g. '6') Kernel config file to use, and, the set of config options to be detected are configurable. See [configuration options](#configuration-options) for more information. ### Memory Features | Feature | Attribute | Description | | ------- | --------- | ------------------------------------------------------ | | numa |
| Multiple memory nodes i.e. NUMA architecture detected | nv | present | NVDIMM device(s) are present ### Network Features | Feature | Attribute | Description | | ------- | ---------- | ----------------------------------------------------- | | sriov | capable | [Single Root Input/Output Virtualization][sriov] (SR-IOV) enabled Network Interface Card(s) present |
| configured | SR-IOV virtual functions have been configured ### PCI Features | Feature | Attribute | Description | | -------------------- | --------- | ----------------------------------------- | | <device label> | present | PCI device is detected `` is composed of raw PCI IDs, separated by underscores. The set of fields used in `` is configurable, valid fields being `class`, `vendor`, `device`, `subsystem_vendor` and `subsystem_device`. Defaults are `class` and `vendor`. An example label using the default label fields: ``` feature.node.kubernetes.io/pci-1200_8086.present=true ``` Also the set of PCI device classes that the feature source detects is configurable. By default, device classes (0x)03, (0x)0b40 and (0x)12, i.e. GPUs, co-processors and accelerator cards are detected. See [configuration options](#configuration-options) for more information on NFD config. ### Storage Features | Feature name | Description | | :--------------: | :---------------------------------------------------------------------------------: | | nonrotationaldisk | Non-rotational disk, like SSD, is present in the node ### System Features | Feature | Attribute | Description | | ----------- | ---------------- | --------------------------------------------| | os_release | ID | Operating system identifier |
| VERSION_ID | Operating system version identifier (e.g. '6.7') |
| VERSION_ID.major | First component of the OS version id (e.g. '6') |
| VERSION_ID.minor | Second component of the OS version id (e.g. '7') ### Feature Detector Hooks (User-specific Features) NFD has a special feature source named *local* which is designed for getting the labels from user-specific feature detector. It provides a mechanism for users to implement custom feature sources in a pluggable way, without modifying nfd source code or Docker images. The local feature source can be used to advertise new user-specific features, and, for overriding labels created by the other feature sources. The *local* feature source gets its labels by two different ways: * It tries to execute files found under `/etc/kubernetes/node-feature-discovery/source.d/` directory. The hook files must be executable. When executed, the hooks are supposed to print all discovered features in `stdout`, one per line. * It reads files found under `/etc/kubernetes/node-feature-discovery/features.d/` directory. The file content is expected to be similar to the hook output (described above). These directories must be available inside the Docker image so Volumes and VolumeMounts must be used if standard NFD images are used. The given template files mount by default the `source.d` and the `features.d` directories respectively from `/etc/kubernetes/node-feature-discovery/source.d/` and `/etc/kubernetes/node-feature-discovery/features.d/` from the host. You should update them to match your needs. In both cases, the labels can be binary or non binary, using either `` or `=` format. Unlike the other feature sources, the name of the file, instead of the name of the feature source (that would be `local` in this case), is used as a prefix in the label name, normally. However, if the `` of the label starts with a slash (`/`) it is used as the label name as is, without any additional prefix. This makes it possible for the user to fully control the feature label names, e.g. for overriding labels created by other feature sources. You can also override the default namespace of your labels using this format: `/[=]`. You must whitelist your namespace using the `--extra-label-ns` option on the master. In this case, the name of the file will not be added to the label name. For example, if you want to add the label `my.namespace.org/my-label=value`, your hook output or file must contains `my.namespace.org/my-label=value` and you must add `--extra-label-ns=my.namespace.org` on the master command line. `stderr` output of the hooks is propagated to NFD log so it can be used for debugging and logging. **A hook example:**
User has a shell script `/etc/kubernetes/node-feature-discovery/source.d/my-source` which has the following `stdout` output: ``` MY_FEATURE_1 MY_FEATURE_2=myvalue /override_source-OVERRIDE_BOOL /override_source-OVERRIDE_VALUE=123 override.namespace/value=456 ``` which, in turn, will translate into the following node labels: ``` feature.node.kubernetes.io/my-source-MY_FEATURE_1=true feature.node.kubernetes.io/my-source-MY_FEATURE_2=myvalue feature.node.kubernetes.io/override_source-OVERRIDE_BOOL=true feature.node.kubernetes.io/override_source-OVERRIDE_VALUE=123 override.namespace/value=456 ``` **A file example:**
User has a file `/etc/kubernetes/node-feature-discovery/features.d/my-source` which contains the following lines: ``` MY_FEATURE_1 MY_FEATURE_2=myvalue /override_source-OVERRIDE_BOOL /override_source-OVERRIDE_VALUE=123 override.namespace/value=456 ``` which, in turn, will translate into the following node labels: ``` feature.node.kubernetes.io/my-source-MY_FEATURE_1=true feature.node.kubernetes.io/my-source-MY_FEATURE_2=myvalue feature.node.kubernetes.io/override_source-OVERRIDE_BOOL=true feature.node.kubernetes.io/override_source-OVERRIDE_VALUE=123 override.namespace/value=456 ``` NFD tries to run any regular files found from the hooks directory. Any additional data files your hook might need (e.g. a configuration file) should be placed in a separate directory in order to avoid NFD unnecessarily trying to execute these. You can use a subdirectory under the hooks directory, for example `/etc/kubernetes/node-feature-discovery/source.d/conf/`. **NOTE!** NFD will blindly run any executables placed/mounted in the hooks directory. It is the user's responsibility to review the hooks for e.g. possible security implications. ## Getting started For a stable version with ready-built images see the [latest released version](https://github.com/kubernetes-sigs/node-feature-discovery/tree/v0.4.0) ([release notes](https://github.com/kubernetes-sigs/node-feature-discovery/releases/latest)). If you want to use the latest development version (master branch) you need to [build your own custom image](#building-from-source). ### System requirements 1. Linux (x86_64/Arm64) 1. [kubectl][kubectl-setup] (properly set up and configured to work with your Kubernetes cluster) 1. [Docker][docker-down] (only required to build and push docker images) ### Usage #### nfd-master Nfd-master runs as a DaemonSet, by default in the master node(s) only. You can use the template spec provided to deploy nfd-master, or use `nfd-master.yaml` generated by `Makefile`. The latter includes `image:` and `namespace:` definitions that match the latest built image. Example: ``` make IMAGE_TAG= docker push kubectl create -f nfd-master.yaml ``` Nfd-master listens for connections from nfd-worker(s) and connects to the Kubernetes API server to add node labels advertised by them. If you have RBAC authorization enabled (as is the default e.g. with clusters initialized with kubeadm) you need to configure the appropriate ClusterRoles, ClusterRoleBindings and a ServiceAccount in order for NFD to create node labels. The provided template will configure these for you. #### nfd-worker Nfd-worker is preferably run as a Kubernetes DaemonSet. There is an example spec (`nfd-worker-daemonset.yaml.template`) that can be used as a template, or, as is when just trying out the service. Similarly to nfd-master above, the `Makefile` also generates `nfd-worker-daemonset.yaml` from the template that you can use to deploy the latest image. Example: ``` make IMAGE_TAG= docker push kubectl create -f nfd-worker-daemonset.yaml ``` Nfd-worker connects to the nfd-master service to advertise hardware features. When run as a daemonset, nodes are re-labeled at an interval specified using the `--sleep-interval` option. In the [template](https://github.com/kubernetes-sigs/node-feature-discovery/blob/master/nfd-worker-daemonset.yaml.template#L26) the default interval is set to 60s which is also the default when no `--sleep-interval` is specified. Feature discovery can alternatively be configured as a one-shot job. There is an example script in this repo that demonstrates how to deploy the job in the cluster. ``` ./label-nodes.sh [] ``` The label-nodes.sh script tries to launch as many jobs as there are Ready nodes. Note that this approach does not guarantee running once on every node. For example, if some node is tainted NoSchedule or fails to start a job for some other reason, then some other node will run extra job instance(s) to satisfy the request and the tainted/failed node does not get labeled. #### nfd-master and nfd-worker in the same Pod You can also run nfd-master and nfd-worker inside a single pod (skip the `sed` part if running the latest released version): ``` sed -E s',^(\s*)image:.+$,\1image: :,' nfd-daemonset-combined.yaml.template > nfd-daemonset-combined.yaml kubectl apply -f nfd-daemonset-combined.yaml ``` Similar to the nfd-worker setup above, this creates a DaemonSet that schedules an NFD Pod an all worker nodes, with the difference that the Pod also also contains an nfd-master instance. In this case no nfd-master service is run on the master node(s), but, the worker nodes are able to label themselves. This may be desirable e.g. in single-node setups. #### TLS authentication NFD supports mutual TLS authentication between the nfd-master and nfd-worker instances. That is, nfd-worker and nfd-master both verify that the other end presents a valid certificate. TLS authentication is enabled by specifying `--ca-file`, `--key-file` and `--cert-file` args, on both the nfd-master and nfd-worker instances. The template specs provided with NFD contain (commented out) example configuration for enabling TLS authentication. The Common Name (CN) of the nfd-master certificate must match the DNS name of the nfd-master Service of the cluster. By default, nfd-master only check that the nfd-worker has been signed by the specified root certificate (--ca-file). Additional hardening can be enabled by specifying --verify-node-name in nfd-master args, in which case nfd-master verifies that the NodeName presented by nfd-worker matches the Common Name (CN) of its certificate. This means that each nfd-worker requires a individual node-specific TLS certificate. #### Usage demo [![asciicast](https://asciinema.org/a/247316.svg)](https://asciinema.org/a/247316) ### Configuration options Nfd-worker supports a configuration file. The default location is `/etc/kubernetes/node-feature-discovery/nfd-worker.conf`, but, this can be changed by specifying the`--config` command line flag. The file is read inside the container, and thus, Volumes and VolumeMounts are needed to make your configuration available for NFD. The preferred method is to use a ConfigMap. For example, create a config map using the example config as a template: ``` cp nfd-worker.conf.example nfd-worker.conf vim nfd-worker.conf # edit the configuration kubectl create configmap nfd-worker-config --from-file=nfd-worker.conf ``` Then, configure Volumes and VolumeMounts in the Pod spec (just the relevant snippets shown below): ``` ... containers: volumeMounts: - name: nfd-worker-config mountPath: "/etc/kubernetes/node-feature-discovery/" ... volumes: - name: nfd-worker-config configMap: name: nfd-worker-config ... ``` You could also use other types of volumes, of course. That is, hostPath if different config for different nodes would be required, for example. The (empty-by-default) [example config](https://github.com/kubernetes-sigs/node-feature-discovery/blob/master/nfd-worker.conf.example) is used as a config in the NFD Docker image. Thus, this can be used as a default configuration in custom-built images. Configuration options can also be specified via the `--options` command line flag, in which case no mounts need to be used. The same format as in the config file must be used, i.e. JSON (or YAML). For example: ``` --options='{"sources": { "pci": { "deviceClassWhitelist": ["12"] } } }' ``` Configuration options specified from the command line will override those read from the config file. Currently, the only available configuration options are related to the [CPU](#cpu-features), [PCI](#pci-features) and [Kernel](#kernel-features) feature sources. ## Building from source **Download the source code:** ``` git clone https://github.com/kubernetes-sigs/node-feature-discovery ``` **Build the container image:**
See [customizing the build](#customizing-the-build) below for altering the container image registry, for example. ``` cd make ``` **Push the container image:**
Optional, this example with Docker. ``` docker push ``` **Change the job spec to use your custom image (optional):** To use your published image from the step above instead of the `quay.io/kubernetes_incubator/node-feature-discovery` image, edit `image` attribute in the spec template(s) to the new location (`//[:]`). ### Customizing the Build There are several Makefile variables that control the build process and the name of the resulting container image. | Variable | Description | Default value | -------------- | ------------------------------------ | ------------------- | | IMAGE_BUILD_CMD | Command to build the image | docker build | IMAGE_REGISTRY | Container image registry to use | quay.io/kubernetes_incubator | IMAGE_NAME | Container image name | node-feature-discovery | IMAGE_TAG_NAME | Container image tag name | <nfd version> | IMAGE_REPO | Container image repository to use | <IMAGE_REGISTRY>/<IMAGE_NAME> | IMAGE_TAG | Full image:tag to tag the image with | <IMAGE_REPO>/<IMAGE_NAME> | K8S_NAMESPACE | nfd-master and nfd-worker namespace | kube-system For example, to use a custom registry: ``` make IMAGE_REGISTRY= ``` Or to specify a build tool different from Docker: ``` make IMAGE_BUILD_CMD="buildah bud" ``` ## Targeting Nodes with Specific Features Nodes with specific features can be targeted using the `nodeSelector` field. The following example shows how to target nodes with Intel TurboBoost enabled. ```yaml apiVersion: v1 kind: Pod metadata: labels: env: test name: golang-test spec: containers: - image: golang name: go1 nodeSelector: feature.node.kubernetes.io/cpu-pstate.turbo: 'true' ``` For more details on targeting nodes, see [node selection][node-sel]. ## References Github issues - [#28310](https://github.com/kubernetes/kubernetes/issues/28310) - [#28311](https://github.com/kubernetes/kubernetes/issues/28311) - [#28312](https://github.com/kubernetes/kubernetes/issues/28312) [Design proposal](https://docs.google.com/document/d/1uulT2AjqXjc_pLtDu0Kw9WyvvXm-WAZZaSiUziKsr68/edit) ## Governance This is a [SIG-node](https://github.com/kubernetes/community/blob/master/sig-node/README.md) subproject, hosted under the [Kubernetes SIGs](https://github.com/kubernetes-sigs) organization in Github. The project was established in 2016 as a [Kubernetes Incubator](https://github.com/kubernetes/community/blob/master/incubator.md) project and migrated to Kubernetes SIGs in 2018. ## License This is open source software released under the [Apache 2.0 License](LICENSE). ## Demo A demo on the benefits of using node feature discovery can be found in [demo](demo/). [cpuid]: http://man7.org/linux/man-pages/man4/cpuid.4.html [intel-rdt]: http://www.intel.com/content/www/us/en/architecture-and-technology/resource-director-technology.html [intel-pstate]: https://www.kernel.org/doc/Documentation/cpu-freq/intel-pstate.txt [intel-sst]: https://www.intel.com/content/www/us/en/architecture-and-technology/speed-select-technology-article.html [sriov]: http://www.intel.com/content/www/us/en/pci-express/pci-sig-sr-iov-primer-sr-iov-technology-paper.html [docker-down]: https://docs.docker.com/install [golang-down]: https://golang.org/dl [gcc-down]: https://gcc.gnu.org [kubectl-setup]: https://kubernetes.io/docs/tasks/tools/install-kubectl [node-sel]: http://kubernetes.io/docs/user-guide/node-selection