Kubernetes Cloud Controller Manager for Equinix Metal

cloud-provider-equinix-metal is the Kubernetes CCM implementation for Equinix Metal. Read more about the CCM in the official Kubernetes documentation.

Requirements

At the current state of Kubernetes, running the CCM requires a few things. Please read through the requirements carefully as they are critical to running the CCM on a Kubernetes cluster.

Version

Recommended versions of Equinix Metal CCM based on your Kubernetes version:

• Equinix Metal CCM version v0.0.4 supports Kubernetes version >=v1.10
• Equinix Metal CCM version v1.0.0+ supports Kubernetes version >=1.15.0

BGP

If you plan on using a BGP, for example for a BGP-based load balancer, you may need to set static routes on your hosts.

Details about BGP can be found in the official Equinix Metal BGP documentation.

Equinix Metal facilities provide BGP peers at certain addresses, normally 169.254.255.1 and 169.254.255.2. These are available in the host configuration via the Equinix Metal API, as well as the metadata on each host.

In order for BGP peering to work, the upstream BGP peers must receive the packets from your device's private IP address. If they come from the public address, they will be dropped.

There are two ways to get the packets to have the correct source address:

• use BGP software that knows how to set the source address on a packet
• set static routes on your host

BGP Software

Some implementations of BGP software support setting a source address for BGP peering packets, including bird, kube-vip and metallb.

CCM helps in this regard. It reads the information about the peers and the correct source address for the device from the Equinix Metal API, and then sets those as annotations on the host, or passes them to the BGP software. Software that knows how to read those annotations, for example, kube-vip, will do the right thing, as will those that are configured to receive it directly, such as metallb. There will be no need to set static routes.

Static Routes

If your BGP software does not support using a specific source IP, then you must set static routes.

You need to retrieve the following:

• your private IPv4 upstream gateway address
• your BGP peer addresses

Before you can retrieve the information, you must enable BGP at both the Equinix Metal project level, and for each device. You can do this in the Equinix Metal Web UI, API or CLI. CCM ensures these settings on the project and each device. However, if you wish to retrieve the information before CCM enables it, for example to run the configuration below, you may need to enable it first.

A sample method:

GATEWAY_IP=$(curl https://metadata.platformequinix.com/metadata | jq -r '.network.addresses[] | select(.public == false and .address_family == 4) | .gateway')
PEERS=$(curl https://metadata.platformequinix.com/metadata | jq -r '.bgp_neighbors[0].peer_ips[]')
for i in ${PEERS}; do
ip route add ${i} via $GATEWAY_IP
done

Deployment

TL;DR

1. Set kubernetes binary arguments correctly, including for VLAN IPs, if used
2. Get your Equinix Metal project and secret API token
3. Deploy your Equinix Metal project and secret API token to your cluster in a Secret
4. Deploy the CCM
5. Deploy the load balancer (optional)

Kubernetes Binary Arguments

Control plane binaries in your cluster must start with the correct flags:

• kubelet: All kubelets in your cluster MUST set the flag --cloud-provider=external. This must be done for every kubelet. Note that k3s sets its own CCM by default. If you want to use the CCM with k3s, you must disable the k3s CCM and enable this one, as --disable-cloud-controller --kubelet-arg cloud-provider=external.
• kube-apiserver and kube-controller-manager must NOT set the flag --cloud-provider. They then will use no cloud provider natively, leaving room for the Equinix Metal CCM.

WARNING: setting the kubelet flag --cloud-provider=external will taint all nodes in a cluster with node.cloudprovider.kubernetes.io/uninitialized. The CCM itself will untaint those nodes when it initializes them. Any pod that does not tolerate that taint will be unscheduled until the CCM is running.

You must set the kubelet flag the first time you run the kubelet. Stopping the kubelet, adding it after, and then restarting it will not work.

Kubernetes node names must match the device name

By default, the kubelet will name nodes based on the node's hostname. Equinix Metal's device hostnames are set based on the name of the device. It is important that the Kubernetes node name matches the device name.

VLANs

If using Equinix Metal Layer 2 VLANs, then you likely are supplying your own private IPs. As CPEM uses the Equinix Metal API to determine IPs for Kubernetes nodes, it does not know about the IPs you manage privately and assign to the node.

In this case, you must assign the node the IP you want as "internal" - used to communicate between nodes in the Kubernetes cluster - using the kubelet option --node-ip. CPEM respects this kubelet option and, when it finds it has been used, will prefer it as a node's "internal" IP address.

Private Elastic IP

If you are using Equinix Metal private Elastic IPs, which you have assigned to a node, and wish to use that IP as the "internal" IP for the Kubernetes node, you must assign the node the selected IP using the kubelet option --node-ip. CPEM respects this kubelet option and, when it finds it has been used, will prefer it as a node's "internal" IP address. CPEM is intelligent enough to recognize that this IP was provided both via --node-ip and via the Equinix Metal API, and will set it only once.

Get Equinix Metal Project ID and API Token

To run cloud-provider-equinix-metal, you need your Equinix Metal project ID and secret API key ID that your cluster is running in. If you are already logged into the Equinix Metal portal, you can create one by clicking on your profile in the upper right then "API keys". To get your project ID click into the project that your cluster is under and select "project settings" from the header. Under General you will see "Project ID". Once you have this information you will be able to fill in the config needed for the CCM.

Deploy Project and API

Copy deploy/template/secret.yaml to someplace useful:

cp deploy/template/secret.yaml /tmp/secret.yaml

Replace the placeholder in the copy with your token. When you're done, the yaml should look something like this:

apiVersion: v1
kind: Secret
metadata:
  name: metal-cloud-config
  namespace: kube-system
stringData:
  cloud-sa.json: |
    {
    "apiKey": "abc123abc123abc123",
    "projectID": "abc123abc123abc123"
    }

Then apply the secret, e.g.:

kubectl apply -f /tmp/secret.yaml`

You can confirm that the secret was created with the following:

$ kubectl -n kube-system get secrets metal-cloud-config
NAME                  TYPE                                  DATA      AGE
metal-cloud-config   Opaque                                1         2m

Deploy CCM

To apply the CCM itself, select your release and apply the manifest:

Example:

RELEASE=v3.8.1
kubectl apply -f https://github.com/kubernetes-sigs/cloud-provider-equinix-metal/releases/download/${RELEASE}/deployment.yaml

The CCM uses multiple configuration options. See the configuration section for all of the options.

Deploy Load Balancer

If you want load balancing to work as well, deploy a supported load-balancer.

CCM provides the correct logic, if necessary, to manage load balancer configs for supported load-balancers.

See further in this document under loadbalancing, for details.

Logging

By default, ccm does minimal logging, relying on the supporting infrastructure from kubernetes. However, it does support optional additional logging levels via the --v=<level> flag. In general:

• --v=2: log most function calls for devices and facilities, when relevant logging the returned values
• --v=3: log additional data when logging returned values, usually entire go structs
• --v=5: log every function call, including those called very frequently

Configuration

The Equinix Metal CCM has multiple configuration options. These include three different ways to set most of them, for your convenience.

1. Command-line flags, e.g. --option value or --option=value; if not set, then
2. Environment variables, e.g. CCM_OPTION=value; if not set, then
3. Field in the configuration Secret; if not set, then
4. Default, if available; if not available, then an error

This section lists each configuration option, and whether it can be set by each method.

Purpose	CLI Flag	Env Var	Secret Field	Default
Path to config secret	cloud-config			error
API Key		METAL_API_KEY	apiKey	error
Project ID		METAL_PROJECT_ID	projectID	error
Metro in which to create LoadBalancer Elastic IPs		METAL_METRO_NAME	metro	Service-specific annotation, else error
Facility in which to create LoadBalancer Elastic IPs, only if Metro is not set		METAL_FACILITY_NAME	facility	Service-specific annotation, else metro
Base URL to Equinix API			base-url	Official Equinix Metal API
Load balancer setting		METAL_LOAD_BALANCER	loadbalancer	none
BGP ASN for cluster nodes when enabling BGP on the project; if the project already has BGP enabled, will use the existing BGP local ASN from the project		METAL_LOCAL_ASN	localASN	65000
BGP passphrase to use when enabling BGP on the project; if the project already has BGP enabled, will use the existing BGP pass from the project		METAL_BGP_PASS	bgpPass	""
Kubernetes annotation to set node's BGP ASN, {{n}} replaced with ordinal index of peer		METAL_ANNOTATION_LOCAL_ASN	annotationLocalASN	"metal.equinix.com/bgp-peers-{{n}}-node-asn"
Kubernetes annotation to set BGP peer's ASN, {{n}} replaced with ordinal index of peer		METAL_ANNOTATION_PEER_ASN	annotationPeerASN	"metal.equinix.com/bgp-peers-{{n}}-peer-asn"
Kubernetes annotation to set BGP peer's IPs, {{n}} replaced with ordinal index of peer		METAL_ANNOTATION_PEER_IP	annotationPeerIP	"metal.equinix.com/bgp-peers-{{n}}-peer-ip"
Kubernetes annotation to set source IP for BGP peering, {{n}} replaced with ordinal index of peer		METAL_ANNOTATION_SRC_IP	annotationSrcIP	"metal.equinix.com/bgp-peers-{{n}}-src-ip"
Kubernetes annotation to set BGP MD5 password, base64-encoded (see security warning below)		METAL_ANNOTATION_BGP_PASS	annotationBGPPass	"metal.equinix.com/bgp-peers-{{n}}-bgp-pass"
Kubernetes annotation to set the CIDR for the network range of the private address		METAL_ANNOTATION_NETWORK_IPV4_PRIVATE	annotationNetworkIPv4Private	metal.equinix.com/network-4-private
Kubernetes Service annotation to set EIP metro		METAL_ANNOTATION_EIP_METRO	annotationEIPMetro	"metal.equinix.com/eip-metro"
Kubernetes Service annotation to set EIP facility		METAL_ANNOTATION_EIP_FACILITY	annotationEIPFacility	"metal.equinix.com/eip-facility"
Tag for control plane Elastic IP		METAL_EIP_TAG	eipTag	No control plane Elastic IP
ID for control plane Equinix Metal Load Balancer		METAL_LOAD_BALANCER_ID	loadBalancerID	No control plane Equinix Metal Load Balancer
Kubernetes API server port for Elastic IP		METAL_API_SERVER_PORT	apiServerPort	Same as kube-apiserver on control plane nodes, same as 0
Filter for cluster nodes on which to enable BGP		METAL_BGP_NODE_SELECTOR	bgpNodeSelector	All nodes
Use host IP for Control Plane endpoint health checks		METAL_EIP_HEALTH_CHECK_USE_HOST_IP	eipHealthCheckUseHostIP	false

Security Warning Including your project's BGP password, even base64-encoded, may have security implications. Because Equinix Metal only allows communication to the BGP peer from the actual node, and not from outside, and because that password already is available form metadata on the host, this risk may be limited. We further recommend using Kubernetes Network Policies to restrict access to BGP peers solely to system pods that have reasonable need to access them.

How It Works

The Kubernetes CCM for Equinix Metal deploys as a Deployment into your cluster with a replica of 1. It provides the following services:

• lists and retrieves instances by ID, returning Equinix Metal servers
• manages load balancers

Service Load Balancers

Equinix CCM supports two approaches to load balancing:

1. If configured to do so, Equinix Metal CCM will interface with and configure external bare-metal load balancers
2. If configured to do so, and if the feature is available on your Equinix Metal account, Equinix Metal CCM will interface with and configure external, managed Equinix Metal Load Balancers (EMLB)

When any load balancer is enabled, the CCM does the following:

1. Enable BGP for the project
2. Enable BGP on each node as it comes up
3. Sets ASNs based on configuration or default
4. If you are using bare-metal load balancers, then for each Service of type=LoadBalancer:
   • If you have specified a load balancer IP on Service.Spec.LoadBalancerIP (bring your own IP, or BYOIP), do nothing
   • If you have not specified a load balancer IP on Service.Spec.LoadBalancerIP, get an Equinix Metal Elastic IP and set it on Service.Spec.LoadBalancerIP, see below
5. Pass control to the specific load balancer implementation

Service Load Balancer IP

There are two options for getting an Elastic IP (EIP) for a Service of type=LoadBalancer: bring-your-own or let CCM create one using the Equinix API.

Whether you bring your own IP or rely on CCM to request one for you, the load balancer IP will be set, and load balancers can consume them.

Bring Your Own IP

Whenever a Service of type=LoadBalancer is encountered, the CCM tries to ensure that an externally accessible load balancer IP is available. It does this in one of two ways:

If you want to use a specific IP that you have ready, either because you brought it from the outside or because you retrieved an Elastic IP from Equinix Metal separately, you can add it to the Service explicitly as Service.Spec.LoadBalancerIP. For example:

apiVersion: v1
kind: Service
metadata:
  name: ip-service
spec:
  selector:
    app: MyAppIP
  ports:
    - protocol: TCP
      port: 80
      targetPort: 9376
  type: LoadBalancer
  loadBalancerIP: 145.60.80.60

CCM will detect that loadBalancerIP already was set and not try to create a new Equinix Metal Elastic IP.

Equinix EIP

If the Service.Spec.LoadBalancerIP was not set, then CCM will use the Equinix Metal API to request a new, metro- or facility-specific Elastic IP and set it to Service.Spec.LoadBalancerIP.

The CCM needs to determine where to request the EIP. It does not attempt to figure out where the nodes are, as that can change over time, the nodes might not be in existence when the CCM is running or Service is created, and you could run a Kubernetes cluster across multiple facilities or potentially regions, or even cloud providers.

The CCM uses the following rules to determine where to create the EIP:

1. if facility is set globally using the environment variable METAL_FACILITY_NAME, use it; else
2. if metro is set globally using the environment variable METAL_METRO_NAME, use it; else
3. if the Service for which the EIP is being created has the annotation indicating in which facility the EIP should be created, use it; else
4. if the Service for which the EIP is being created has the annotation indicating in which metro the EIP should be created, use it; else
5. Return an error, cannot set an EIP

The overrides of environment variable and config file are provided so that you can run explicitly control where the EIPs are created at a system-wide level, ignoring the annotations.

Using these flags and annotations, you can run the CCM on a node in a different metro or facility, or even outside of Equinix Metal entirely.

Service LoadBalancer Implementations

Loadbalancing is enabled as follows.

1. If the environment variable METAL_LOAD_BALANCER is set, read that. Else...
2. If the config file has a key named loadbalancer, read that. Else...
3. Load balancing is disabled.

The value of the loadbalancing configuration is <type>:///<detail> where:

• <type> is the named supported type, of one of those listed below
• <detail> is any additional detail needed to configure the implementation, details in the description below

For loadbalancing for Kubernetes Service of type=LoadBalancer, the following implementations are supported:

• Equinix Metal Load Balancer
• kube-vip
• MetalLB
• empty

CCM does not deploy any load balancers for you. It limits itself to managing the Equinix Metal-specific API calls to support a load balancer, and providing configuration for supported load balancers.

Equinix Metal Load Balancer

Equinix Metal Load Balancer (EMLB) is a beta service that is available to a limited number of Equinix Metal customers that provides managed layer 4 load balancers.

When the EMLB option is enabled, for user-deployed Kubernetes Service of type=LoadBalancer, the Equinix Metal CCM:

• creates an Equinix Metal Load Balancer for the service
• creates listener ports on the Equinix Metal Load Balancer for each port on the service
• creates origin pools for each listener port that send traffic to the corresponding NodePorts in your cluster

To enable EMLB, set the configuration METAL_LOAD_BALANCER or config loadbalancer to:

emlb:///<metro>

Where <metro> is the Equinix metro in which you want CCM to deploy your external load balancers. For example, to deploy your load balancers in Silicon Valley, you would set the configuration to emlb:///sv. Note that EMLB is available in a limited number of Equinix metros (as of this writing, sv, da, and ny).

kube-vip

Supported Versions:

• Equinix Metal CCM version < v3.3.0 supports kube-vip version < v0.5.11
• Equinix Metal CCM version >= v3.3.0 supports kube-vip version >= v0.5.11

When the kube-vip option is enabled, for user-deployed Kubernetes Service of type=LoadBalancer, the Equinix Metal CCM enables BGP on the project and nodes, assigns an EIP for each such Service, and adds annotations to the nodes. These annotations are configured to be consumable by kube-vip.

To enable it, set the configuration METAL_LOAD_BALANCER or config loadbalancer to:

kube-vip://

Directions on using configuring kube-vip in this method are available at the kube-vip site

If kube-vip management is enabled, then CCM does the following.

1. Enable BGP on the Equinix Metal project
2. For each node currently in the cluster or added:
   • retrieve the node's Equinix Metal ID via the node provider ID
   • retrieve the device's BGP configuration: node ASN, peer ASN, peer IPs, source IP
   • add the information to appropriate annotations on the node
3. For each service of type=LoadBalancer currently in the cluster or added:
   • if an Elastic IP address reservation with the appropriate tags exists, and the Service already has that IP address affiliated with it, it is ready; ignore
   • if an Elastic IP address reservation with the appropriate tags exists, and the Service does not have that IP affiliated with it, add it to the service spec
   • if an Elastic IP address reservation with the appropriate tags does not exist, create it and add it to the services spec; see Equinix EIP to control in which metro or facility the EIP will be created.
4. For each service of type=LoadBalancer deleted from the cluster:
   • find the Elastic IP address from the service spec and remove it
   • delete the Elastic IP reservation from Equinix Metal

MetalLB

Supported Versions: MetalLB version 0.11.0 through version 0.13.7.

When MetalLB is enabled, for user-deployed Kubernetes Service of type=LoadBalancer, the Equinix Metal CCM uses BGP and to provide the equivalence of load balancing, without requiring an additional managed service (or hop). BGP route advertisements enable Equinix Metal's network to route traffic for your services at the Elastic IP to the correct host.

NOTE: MetalLB 0.13.2+ uses CRs for configuration, and no longer uses a ConfigMap. Currently, the CCM defaults to using a ConfigMap for backwards compatibility. In a future release, the CCM will default to using CRDs with MetalLB.

To configure the CCM to integrate with MetalLB <= v0.12.1, follow the instructions in MetalLB from v0.11.0 to v0.12.1.

To configure the CCM to integrate with MetalLB >= v0.13.2, follow the instructions in MetalLB after v0.13.2.

MetalLB common configuration

CCM adds nodeSelector entries that are specifically structured to be ignored by metallb.

For example:

node-selectors:
  - match-labels:
      kubernetes.io/hostname: dc-worker-1
  - match-labels:
      nomatch.metal.equinix.com/service-namespace: default
      nomatch.metal.equinix.com/service-name: nginx-deployment
  - match-labels:
      nomatch.metal.equinix.com/service-namespace: ai
      nomatch.metal.equinix.com/service-name: trainer

node-selectors are grouped together with a logical OR. The above thus means that it will match any node that has any of the 3 sets of labels. The node with the hostname dc-worker-1 will be matched, independent of the other selectors.

The remaining selectors are used to allow CCM to track which services are being announced by which node. These are ignored, as long as no such labels exist on any nodes. This is why the labels are called the clearly non-matching names of nomatch.metal.equinix.com/service-namespace and nomatch.metal.equinix.com/service-name

MetalLB from v0.11.0 to v0.12.1

To enable it, set the configuration METAL_LOAD_BALANCER or config loadbalancer to:

metallb:///<configMapNamespace>/<configMapName>

For example:

• metallb:///metallb-system/config - enable MetalLB management and update the configmap config in the namespace metallb-system
• metallb:///foonamespace/myconfig - - enable MetalLB management and update the configmap myconfig in the namespace foonamespae
• metallb:/// - enable MetalLB management and update the default configmap, i.e. config in the namespace metallb-system

Notice the *three slashes. In the URL, the namespace and the configmap are in the path.

By default, the CCM configures MetalLB using a ConfigMap. ConfigMap configuration only works with MetalLB <= v0.12.1. For forward compatibility, you may optionally append ?crdConfiguration=false to the configuration string in order to explicitly tell the CCM to use a ConfigMap to configure MetalLB. In a future release, the CCM will default to using CRDs with MetalLB.

When enabled, CCM controls the loadbalancer by updating the provided ConfigMap.

If MetalLB management is enabled, then CCM does the following.

1. Get the appropriate namespace and name of the ConfigMap, based on the rules above.
2. If the ConfigMap does not exist, do the rest of the behaviours, but do not update the ConfigMap
3. Enable BGP on the Equinix Metal project
4. For each node currently in the cluster or added:
   • retrieve the node's Equinix Metal ID via the node provider ID
   • retrieve the device's BGP configuration: node ASN, peer ASN, peer IPs, source IP
   • add them to the metallb ConfigMap with a kubernetes selector ensuring that the peer is only for this node
5. For each node deleted from the cluster:
   • remove the node from the MetalLB ConfigMap
6. For each service of type=LoadBalancer currently in the cluster or added:
   • if an Elastic IP address reservation with the appropriate tags exists, and the Service already has that IP address affiliated with it, it is ready; ignore
   • if an Elastic IP address reservation with the appropriate tags exists, and the Service does not have that IP affiliated with it, add it to the service spec and ensure it is in the pools of the MetalLB ConfigMap with auto-assign: false
   • if an Elastic IP address reservation with the appropriate tags does not exist, create it and add it to the services spec, and ensure is in the pools of the metallb ConfigMap with auto-assign: false; see Equinix EIP to control in which metro or facility the EIP will be created.
7. For each service of type=LoadBalancer deleted from the cluster:
   • find the Elastic IP address from the service spec and remove it
   • remove the IP from the ConfigMap
   • delete the Elastic IP reservation from Equinix Metal

CCM itself does not deploy the load-balancer or any part of it, including the ConfigMap. It only modifies an existing ConfigMap. This can be deployed by the administrator separately, using the manifest provided in the releases page, or in any other manner.

In order to instruct metallb which IPs to announce and from where, CCM takes direct responsibility for managing the metallb ConfigMap. As described above, this is normally at metallb-system/config.

You should not attempt to modify this ConfigMap separately, as CCM will modify it with each loop. Modifying it separately is likely to break metallb's functioning.

MetalLB after v0.13.2

To enable the CCM to use MetalLB v0.13.2+, you must set the configuration METAL_LOAD_BALANCER or config loadbalancer to:

metallb:///<configMapNamespace>?crdConfiguration=true

Note that the ?crdConfiguration=true is required in order for the CCM to correctly configure MetalLB v0.13.2+ via CRDs instead of using a ConfigMap. Currently, the CCM defaults to using a ConfigMap for backwards compatibility. In a future release, the CCM will default to using CRDs with MetalLB.

For example:

• metallb:///metallb-system?crdConfiguration=true - enable MetalLB management and update configuration in the namespace metallb-system (default)
• metallb:///foonamespace?crdConfiguration=true - enable MetalLB management and update configuration in the namespace metallb-system
• metallb:///?crdConfiguration=true - enable MetalLB management and update configuration in the default namespace metallb-system

Notice the *three slashes. In the URL, the namespace are in the path.

If MetalLB management is enabled, then CCM does the following.

1. Get the appropriate namespace, based on the rules above.
2. Enable BGP on the Equinix Metal project
3. For each node currently in the cluster or added:
   • retrieve the node's Equinix Metal ID via the node provider ID
   • retrieve the device's BGP configuration: node ASN, peer ASN, peer IPs, source IP
   • create a bgpeers.metallb.io for each peer IP with a kubernetes selector ensuring that those BGPPeers are only for this node
4. For each node deleted from the cluster:
   • delete the affiliated BGPeers.
5. For each service of type=LoadBalancer currently in the cluster or added:
   • if an Elastic IP address reservation with the appropriate tags exists, and the Service already has that IP address affiliated with it, it is ready; ignore
   • if an Elastic IP address reservation with the appropriate tags exists, and the Service does not have that IP affiliated with it, add it to the service spec and ensure there is an ipaddresspools.metallb.io with auto-assign: false, and there is an elegible bgpadvertisement.metallb.io. If no bgpadvertisement exists with the appropriate tag ("cloud-provider":"equinix-metal"), a default bgpadvertisement "equinix-metal-bgp-adv" with the ipaddresspool name in the ipAddressPools spec will be created.
   • if an Elastic IP address reservation with the appropriate tags does not exist, create it and add it to the services spec, and ensure there is an ipaddresspools.metallb.io with auto-assign: false, and there is an elegible bgpadvertisement.metallb.io. If no bgpadvertisement exists with the appropriate tag ("cloud-provider":"equinix-metal"), a default bgpadvertisement "equinix-metal-bgp-adv" with the ipaddresspool name in the ipAddressPools spec will be created; see Equinix EIP to control in which metro or facility the EIP will be created.
6. For each service of type=LoadBalancer deleted from the cluster:
   • find the Elastic IP address from the service spec and remove it
   • remove the affiliated ipaddresspools.metallb.io
   • If there is no other service, delete all CCM managed bgpeers and the default bgpadvertisement
   • delete the Elastic IP reservation from Equinix Metal

NOTE: IP Address sharing is not yet supported in Cloud Provider Equinix Metal.

CCM itself does not install/deploy the load-balancer and it may exists before enable it. This can be deployed by the administrator separately, using the manifest provided in the releases page, or in any other manner. Not having metallb installed but enabled in the CCM configuration will end up allowing you to continue deploying kubernetes services, but the external ip assignment will remain pending, making it useless.

In order to instruct metallb which IPs to announce and from where, CCM takes direct responsibility for managing the metallb configuration. As described above, this is normally at metallb-system. Users can create and manage their own bgpadvertisements.metallb.io resources for advanced configuration, but they must have the appropriate tag ("cloud-provider":"equinix-metal") to prevent the CCM from creating a default bgpadvertisement.

You should not attempt to modify metallb resources created by the CCM separately, as CCM will modify it with each loop. Modifying it separately is likely to break metallb's functioning.

empty

When the empty option is enabled, for user-deployed Kubernetes Service of type=LoadBalancer, the Equinix Metal CCM enables BGP on the project and nodes, assigns an EIP for each such Service, and adds annotations to the nodes. It does not integrate directly with any load balancer. This is useful if you have your own implementation, but want to leverage Equinix Metal CCM's management of BGP and EIPs.

To enable it, set the configuration METAL_LOAD_BALANCER or config loadbalancer to:

empty://

If empty management is enabled, then CCM does the following.

1. Enable BGP on the Equinix Metal project
2. For each node currently in the cluster or added:
   • retrieve the node's Equinix Metal ID via the node provider ID
   • retrieve the device's BGP configuration: node ASN, peer ASN, peer IPs, source IP
   • add the information to appropriate annotations on the node
3. For each service of type=LoadBalancer currently in the cluster or added:
   • if an Elastic IP address reservation with the appropriate tags exists, and the Service already has that IP address affiliated with it, it is ready; ignore
   • if an Elastic IP address reservation with the appropriate tags exists, and the Service does not have that IP affiliated with it, add it to the service spec
   • if an Elastic IP address reservation with the appropriate tags does not exist, create it and add it to the services spec
4. For each service of type=LoadBalancer deleted from the cluster:
   • find the Elastic IP address from the service spec and remove it
   • delete the Elastic IP reservation from Equinix Metal

Language

In order to ease understanding, we use several different terms for an IP address:

• Requested: A dedicated /32 IP address has been requested for the service from Equinix Metal. It may be returned immediately, or it may need to wait for Equinix Metal intervention.
• Reserved: A dedicated /32 IP address has been reserved for the service from Equinix Metal.
• Assigned: The dedicated IP address has been marked on the service as Service.Spec.LoadBalancerIP as assigned.
• Mapped: The dedicated IP address has been added to the metallb ConfigMap as available.

From Equinix Metal's perspective, the IP reservation is either Requested or Reserved, but not both. For the load balancer to work, the IP address needs to be all of: Reserved, Assigned, Mapped.

Control Plane Load Balancing

CCM implements an optional control plane load balancer using one of two approaches:

1. an Equinix Metal Load Balancer
2. an Equinix Metal Elastic IP (EIP) and the Equinix Metal API's ability to assign that EIP to different devices.

You have several options for control plane load-balancing:

• CCM managed
• kube-vip managed
• No control plane load-balancing (or at least, none known to CCM)

CCM Managed

Equinix Metal Load Balancing

If you have configured the CCM to use Equinix Metal Load Balancers (EMLB) for service load balancing, you can also choose to use EMLB for control plane load balancing. To enable control plane load balancing with EMLB:

1. Create a Load Balancer using the Equinix Metal API or Web UI
2. When starting the CCM
   • set the configuration for load balancing with EMLB, e.g. env var METAL_LOAD_BALANCER=emlb:///<metro>, where <metro> is the metro in which you want the CCM to create your load balancers
   • set the configuration for the control plane EIP tag, e.g. env var METAL_LOAD_BALANCER_ID=<id>, where <id> is the ID of the Load Balancer you created earlier

When run with the correct configuration, on startup, CCM will automatically update your Load Balancer to send traffic to your control plane nodes.

Elastic IP Load Balancer

It is a common procedure to use Elastic IP as Control Plane endpoint in order to have a static endpoint that you can use from the outside, or when configuring the advertise address for the kubelet.

To enable CCM to manage the control plane EIP:

1. Create an Elastic IP, using the Equinix Metal API, Web UI or CLI
2. Put an arbitrary but unique tag on the EIP
3. When starting the CCM
   • set the configuration for the control plane EIP tag, e.g. env var METAL_EIP_TAG=<tag>, where <tag> is whatever tag you set on the EIP
   • (optional) set the port that the EIP should listen on; by default, or when set to 0, it will use the same port as the kube-apiserver on the control plane nodes. This port can also be specified with METAL_API_SERVER_PORT=<port>.
   • (optional) set the configuration for using the host IP for control plane endpoint health checks. This is needed when the EIP is configured as an loopback IP address, such as the case with CAPP

In CAPP we create one for every cluster for example. Equinix Metal does not provide an as a service load balancer it means that in some way we have to check if the Elastic IP is still assigned to an healthy control plane.

In order to do so CCM implements a reconciliation loop that checks if the Control Plane Endpoint respond correctly using the /healthz endpoint.

When the healthcheck fails CCM looks for the other Control Planes, when it gets a healthy one it move the Elastic IP to the new device.

This feature by default is disabled and it assumes that the ElasticIP for the cluster is available and tagged with an arbitrary label. CAPP for example uses:

cluster-api-provider-packet:cluster-id:<clusterName>

When the tag is present CCM will filter the available elastic ip for the specified project via tag to lookup the one used by your cluster.

It will check the correct answer, when it stops responding the IP reassign logic will start.

The logic will circle over all the available control planes looking for an active api server. As soon as it can find one the Elastic IP will be unassigned and reassigned to the working node.

How the Elastic IP Traffic is Routed

Of course, even if the router sends traffic for your Elastic IP (EIP) to a given control plane node, that node needs to know to process the traffic. Rather than require you to manage the IP assignment on each node, which can lead to some complex timing issues, the Equinix Metal CCM handles it for you.

The structure relies on the already existing default/kubernetes service, which creates an Endpoints structure that includes all of the functioning control plane nodes. The CCM does the following on each loop:

1. Reads the Kubernetes-created default/kubernetes service to discover:
   • what port kube-apiserver is listening on from targetPort
   • all of the endpoints, i.e. control plane nodes where kube-apiserver is running
2. Creates a service named kube-system/cloud-provider-equinix-metal-kubernetes-external with the following settings:
   • type=LoadBalancer
   • spec.loadBalancerIP=<eip>
   • status.loadBalancer.ingress[0].ip=<eip>
   • metadata.annotations["metallb.universe.tf/address-pool"]=disabled-metallb-do-not-use-any-address-pool
   • spec.ports[0].targetPort=<targetPort>
   • spec.ports[0].port=<targetPort_or_override>
3. Updates the service kube-system/cloud-provider-equinix-metal-kubernetes-external to have endpoints identical to those in default/kubernetes

This has the following effect:

• the annotation prevents metallb from trying to manage the IP
• the name prevents CCM from passing it to the loadbalancer provider address mapping, thus preventing any of them from managing it
• the spec.loadBalancerIP and status.loadBalancer.ingress[0].ip cause kube-proxy to set up routes on all of the nodes
• the endpoints cause the traffic to be routed to the control plane nodes

Note that we wanted to just set externalIPs on the original default/kubernetes, but that would prevent traffic from being routed to it from the control nodes, due to iptables rules. LoadBalancer types allow local traffic.

kube-vip Managed

kube-vip has the ability to manage the Elastic IP and control plane load-balancing. To enable it:

1. Disable CCM control-plane load-balancing, by ensuring the EIP tag setting is empty via METAL_EIP_TAG=""
2. Enable kube-vip control plane load-balancing by following the instructions here

Core Control Loop

The CCM does not maintain its own control loop, instead relying on the services provided by cloud-provider.

On startup, the CCM:

1. Implements the cloud-provider interface, providing primarily the following API calls:
   • Initialize()
   • InstancesV2()
   • LoadBalancer()
2. In Initialize:
   1. If BGP is configured, enable BGP on the project
   2. If EIP control plane management is enabled, create an informer for Service, Node and Endpoints, updating the control plane EIP as needed.

The CCM then relies on the cloud-provider control loop to call it:

• whenever a Node is added, to get node metadata
• whenever a Service of type=LoadBalancer is added, removed or updated
• if EIP control plane management is enabled, via shared informers:
  • whenever a control plane Node is added, removed or updated
  • whenever the default/kubernetes service is added or updated
  • whenever the endpoints behind the default/kubernetes service are added, updated or removed

Further, it relies on the resync property of the above to ensure it always is up to date, and did not miss any events.

BGP Configuration

If a loadbalancer is enabled, the CCM enables BGP for the project and enables it by default on all nodes as they come up. It sets the ASNs as follows:

• Node, a.k.a. local, ASN: 65000
• Peer Router ASN: 65530

These are the settings per Equinix Metal's BGP config, see here. It is not recommended to override them. However, you can do so, using the options in Configuration.

Set of servers on which BGP will be enabled can be filtered as well, using the the options in Configuration. Value for node selector should be a valid Kubernetes label selector (e.g. key1=value1,key2=value2).

Node Annotations

The Equinix Metal CCM sets Kubernetes annotations on each cluster node.

• Node, or local, ASN, default annotation metal.equinix.com/bgp-peers-{{n}}-node-asn
• Peer ASN, default annotation metal.equinix.com/bgp-peers-{{n}}-peer-asn
• Peer IP, default annotation metal.equinix.com/bgp-peers-{{n}}-peer-ip
• Source IP to use when communicating with peer, default annotation metal.equinix.com/bgp-peers-{{n}}-src-ip
• BGP password for peer, default annotation metal.equinix.com/bgp-peers-{{n}}-bgp-pass
• CIDR of the private network range in the project which this node is part of, default annotation metal.equinix.com/network-4-private

These annotation names can be overridden, if you so choose, using the options in Configuration.

Note that the annotations for BGP peering are a pattern. There is one annotation per data point per peer, following the pattern metal.equinix.com/bgp-peers-{{n}}-<info>, where:

• {{n}} is the number of the peer, always starting with 0
• <info> is the relevant information, such as node-asn or peer-ip

For example:

• metal.equinix.com/bgp-peers-0-peer-asn - ASN of peer 0
• metal.equinix.com/bgp-peers-1-peer-asn - ASN of peer 1
• metal.equinix.com/bgp-peers-0-peer-ip - IP of peer 0
• metal.equinix.com/bgp-peers-1-peer-ip - IP of peer 1

Elastic IP Configuration

If a loadbalancer is enabled, CCM creates an Equinix Metal Elastic IP (EIP) reservation for each Service of type=LoadBalancer. It tags the Reservation with the following tags:

• usage="cloud-provider-equinix-metal-auto"
• service="<service-hash>" where <service-hash> is the sha256 hash of <namespace>/<service-name>. We do this so that the name of the service does not leak out to Equinix Metal itself.
• cluster=<clusterID> where <clusterID> is the UID of the immutable kube-system namespace. We do this so that if someone runs two clusters in the same project, and there is one Service in each cluster with the same namespace and name, then the two EIPs will not conflict.

IP addresses always are created /32.