netbox-operator

NetBox Operator

Disclaimer: This project is currently under development and may change rapidly, including breaking changes. Use with caution in production environments.

NetBox Operator extends the Kubernetes API by allowing users to manage NetBox resources – such as IP addresses, prefixes, L2VPNs and ASNs – directly through Kubernetes. This integration brings Kubernetes-native features like reconciliation, ensuring that network configurations are maintained automatically, thereby improving both efficiency and reliability.

The Claim Model

The NetBox Operator implements a "Claim Model" which is also used in the Kubernetes PersistentVolumeClaims (PVCs). In this case, instead of disk storage, NetBox Operator dynamically allocates network resources (Prefixes, IP Addresses, and ASNs) based on claims submitted via custom resources.

Purpose

This model ensures a declarative management of IP addressing, subnet allocation, and ASN assignment, with full NetBox integration. The users will create claims (PrefixClaims, IPAddressClaims & AsnClaims), and the NetBox Operator will resolve them into actual Prefixes, IPAddresses and Asns within a designated parent resource.

Getting Started

Prerequisites

• go version v1.25.1+
• docker version 17.03+
• kubectl version v1.11.3+
• Access to a Kubernetes v1.11.3+ cluster
• kind
• docker cli

Installation methods

There are several ways to install NetBox Operator on your Cluster:

• NetBox Operator Helm Chart. More information: https://github.com/netbox-community/netbox-chart/
• Manifests in <config/default> of this repo. Make sure to first set the correct image using kustomize edit set image controller=<correctimage>. Images can be found on the Releases page on GitHub
• The Makefile targets in this repository.
• For debugging and developing, please read further below.

How to use NetBox Operator

Running both NetBox Operator and NetBox on a local kind cluster

Note: This requires Docker BuildKit.

Note: There is currently a bug where if Docker uses containerd for pulling and storing images, kind fails to load the image into the cluster (GitHub Issue). To resolve this, temporarily disable this option in the Docker settings: "General > Use containerd for pulling and storing images"

• Create kind cluster with a NetBox deployment: make create-kind
• Deploy the NetBox Operator on the local kind cluster: make deploy-kind (In case you're using podman use CONTAINER_TOOL=podman make deploy-kind)

To optionally access the NetBox UI:

• Port-forward NetBox: kubectl port-forward deploy/netbox 8080:8080 -n default
• Open http://localhost:8080 in your favorite browser and log in with the username admin and password admin, you will be able to access the local NetBox instance running in the kind cluster.

Testing NetBox Operator using samples

In the folder config/samples/ you can find example manifests to create IpAddress, IpAddressClaim, Prefix, PrefixClaim, L2VPN, L2VPNClaim, Asn, and AsnClaim resources. Apply them to the cluster with kubectl apply -f <file-name> and use your favorite Kubernetes tools to display.

Example of assigning a Prefix using PrefixClaim:

1. Apply a PrefixClaim: kubectl apply -f config/samples/netbox_v1_prefixclaim.yaml
2. Wait for ready condition: kubectl wait prefix prefixclaim-sample --for=condition=Ready
3. List PrefixClaim and Prefix resources: kubectl get pxc,px
4. In the prefix status fields you’ll be able to see the netbox URL of the resource. Login with the default admin/admin credentials to access the NetBox resources.

Key information can be found in the yaml formatted output of these resources, as well as in the events and Operator logs.

To test at scale, you can use yq to patch the Kubernetes manifests. The following is an example to create 100 IpAddressClaims based on the sample yaml file:

for i in {001..100}; do
  name="ipc-${i}" yq e '.metadata.name=strenv(name)' config/samples/netbox_v1_ipaddressclaim.yaml | kubectl apply -f -
done

ASN Management

NetBox Operator supports managing ASNs (Autonomous System Numbers) through two custom resources:

• Asn: Represents a single ASN in NetBox. Similar to an IpAddress, it manages the lifecycle of a specific ASN value.
• AsnClaim: Claims an available ASN from a NetBox ASN Range. Similar to IpAddressClaim, it creates a child Asn CR with the assigned value.

Example: Claiming an ASN

1. Apply an AsnClaim: kubectl apply -f config/samples/netbox_v1_asnclaim.yaml
2. Wait for ready condition: kubectl wait asnclaim asnclaim-sample --for=condition=Ready
3. List AsnClaim and Asn resources: kubectl get asnc,asn

The parentAsnRange field in the AsnClaim spec must match the name of an existing ASN Range in NetBox. The operator will claim an available ASN from that range.

RIR assignment

NetBox requires every ASN to belong to a RIR (Regional Internet Registry).

• On an Asn, rir is required and must match the name of an existing RIR in NetBox.
• On an AsnClaim, rir is optional. When omitted, the RIR of the parent ASN Range is inherited and written to the generated Asn CR.

rir is mutable on both resources and is not part of the restoration hash, so changing it never causes an ASN to be re-claimed. When the field changes, the operator updates the ASN in NetBox.

Restoration (via preserveInNetbox: true) works the same way as for IP Addresses and Prefixes — the ASN is preserved in NetBox upon CR deletion and can be reclaimed when the AsnClaim is re-created.

L2VPN Management

NetBox Operator supports managing L2VPNs (Layer 2 VPNs, e.g. to track VXLAN VNIs) through two custom resources:

• L2VPN: Represents a single L2VPN in NetBox. Similar to an IpAddress, it manages the lifecycle of a specific L2VPN (type, identifier) using the CR's Kubernetes object name as the NetBox L2VPN name.
• L2VPNClaim: Claims a VNI for an L2VPN from an identifierRangeStart/identifierRangeEnd range. Set both to the same value to claim an exact VNI. Similar to IpAddressClaim, it creates a child L2VPN CR with the assigned identifier.

Only VXLAN-based L2VPN types (vxlan, vxlan-evpn) are supported, since those are the ones that carry a VNI (0-16777215) in their identifier.

Example: Claiming an L2VPN

1. Apply an L2VPNClaim: kubectl apply -f config/samples/netbox_v1_l2vpnclaim.yaml
2. Wait for ready condition: kubectl wait l2vpnclaim l2vpnclaim-sample --for=condition=Ready
3. List L2VPNClaim and L2VPN resources: kubectl get l2vc,l2v

identifierRangeStart and identifierRangeEnd are both required on L2VPNClaim; set them to the same value for an exact VNI, or a wider range to let the operator pick the next free VNI in NetBox from that range.

Restoration (via preserveInNetbox: true) works the same way as for IP Addresses and Prefixes — the L2VPN is preserved in NetBox upon CR deletion and can be reclaimed when the L2VPNClaim is re-created.

Mixed usage of Prefixes

Note that NetBox does handle the Address management of Prefixes separately from IP Ranges and IP Addresses. This is important to know when you plan to use the same NetBox Prefix as a parentPrefix for your IpAddressClaims, IpRangeClaims and PrefixClaims.

Example:

• Assume you use an existing empty NetBox Prefix "192.168.0.0/24" as the .spec.parentPrefix for your PrefixClaims, IpAddressClaims and IpRangeClaims.
• You create a PrefixClaim with .spec.prefixLength of /25, NetBox Operator will assign "192.168.0.0/25"
• You create a IpAddressClaim, NetBox Operator will assign "192.168.0.1/32". Important: NetBox ignores the Prefix in that case and will not return "192.168.0.129" as the first available IP!
• You create a IpAddressClaim with .spec.size of 2, NetBox Operator will assign "192.168.0.2/32" to "192.168.0.3/32". Important: NetBox ignores the Prefix in that case and will not return "192.168.0.129" as the first available IP!

This means that you need to plan your automation carefully. As a rule of thumb:

• If you plan mixed use of the same parentPrefix for both single IPs (/32s) as well as Prefixes (non /32s), use PrefixClaims for everything and avoid using IpRangeClaims and IpAddressClaims.
• If you are in full control of a Prefix and you know it will only be used for assigning IP Addresses and IP Ranges, you can use IpAddressClaims and IpRangeClaims.
• If you don't know what the parentPrefix is used for, avoid using IpAddressClaims and IpRangeClaims.

The same applies if you use parentPrefixSelector with PrefixClaims. The above example is IPv4 based but will be the same with IPv6 equivalents.

Restoration from NetBox

In the case that the cluster containing the NetBox Custom Resources managed by this NetBox Operator is not backed up (e.g. using Velero), we need to be able to restore some information from NetBox. This includes two mechanisms implemented in this NetBox Operator:

• IpAddressClaim, PrefixClaim, and L2VPNClaim have the flag preserveInNetbox in their spec. If set to true, the NetBox Operator will not delete the assigned IP Address/Prefix/L2VPN in NetBox when the Kubernetes Custom Resource is deleted
• In NetBox, a custom field (by default netboxOperatorRestorationHash) is used to identify an IP Address/Prefix/L2VPN based on data from the IpAddressClaim/PrefixClaim/L2VPNClaim resource

Use Cases for this Restoration:

• Disaster Recovery: In case the cluster is lost, IP Addresses can be restored with the IPAddressClaim only
• Sticky IPs/VNIs: Some services do not handle changes to IPs or VNIs well. This ensures the IP/Prefix/VNI assigned to a Custom Resource is always the same.

ParentPrefixSelector in PrefixClaim

Please read ParentPrefixSelector guide for more information!

Project Distribution

Following are the steps to build the installer and distribute this project to users.

1. Build the installer for the image built and published in the registry:

make build-installer IMG=<some-registry>/netbox-operator:tag

NOTE: The makefile target mentioned above generates an 'install.yaml' file in the dist directory. This file contains all the resources built with Kustomize, which are necessary to install this project without its dependencies.

1. Using the installer

Users can just run kubectl apply -f <URL for YAML BUNDLE> to install the project, i.e.:

kubectl apply -f https://raw.githubusercontent.com/<org>/netbox-operator/<tag or branch>/dist/install.yaml

Monitoring

When the operator is deployed with the default kustomization (located at config/default/) the metrics endpoint is already exposed and provides the default kubebuilder metrics.

For the monitoring of the state of the CRs reconciled by the operator kube state metrics can be used, check the kube-state-metrics documentation for instructions on configuring it to collect metrics from custom resources.

FAQ

What is the difference between .spec.customFields and .spec.parentPrefixSelector?

.spec.customFields are the NetBox Custom Fields assigned to the resource in NetBox. .spec.parentPrefixSelector is used by a Claim Controller (e.g. the controller of PrefixClaim) to find a suitable Prefix to get e.g. a Prefix from.

What is the difference between .spec.tenant and .spec.parentPrefixSelector.tenant?

.spec.tenant is the tenant that is assigned to the resource in NetBox. .spec.parentPrefixSelector.tenant is used by a Claim Controller (e.g. the controller of PrefixClaim) to find a suitable Prefix to get e.g. a Prefix from.

Contributing

We cordially invite collaboration from the community to enhance the quality and functionality of this project. Whether you are addressing bugs, introducing new features, refining documentation, or assisting with items on our to-do list, your contributions are highly valued and greatly appreciated. Please take a look at Contribution guide for more details.

License

Copyright 2024 Swisscom (Schweiz) AG.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.