Add cloud provider for Rancher with RKE2

Signed-off-by: Cyrill Troxler <[email protected]>

cluster-autoscaler/README.md

@@ -33,6 +33,7 @@ You should also take a look at the notes and "gotchas" for your specific cloud p
 * [Vultr](./cloudprovider/vultr/README.md)
 * [TencentCloud](./cloudprovider/tencentcloud/README.md)
 * [Scaleway](./cloudprovider/scaleway/README.md)
+* [Rancher](./cloudprovider/rancher/README.md)
 
 # Releases
 
@@ -180,3 +181,4 @@ Supported cloud providers:
 * TencentCloud https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/tencentcloud/README.md
 * BaiduCloud https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/baiducloud/README.md
 * Huawei Cloud https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/huaweicloud/README.md
+* Rancher https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/rancher/README.md

cluster-autoscaler/cloudprovider/builder/builder_all.go

@@ -1,5 +1,5 @@
-//go:build !gce && !aws && !azure && !kubemark && !alicloud && !magnum && !digitalocean && !clusterapi && !huaweicloud && !ionoscloud && !linode && !hetzner && !bizflycloud && !brightbox && !packet && !oci && !vultr && !tencentcloud && !scaleway && !externalgrpc && !civo
-// +build !gce,!aws,!azure,!kubemark,!alicloud,!magnum,!digitalocean,!clusterapi,!huaweicloud,!ionoscloud,!linode,!hetzner,!bizflycloud,!brightbox,!packet,!oci,!vultr,!tencentcloud,!scaleway,!externalgrpc,!civo
+//go:build !gce && !aws && !azure && !kubemark && !alicloud && !magnum && !digitalocean && !clusterapi && !huaweicloud && !ionoscloud && !linode && !hetzner && !bizflycloud && !brightbox && !packet && !oci && !vultr && !tencentcloud && !scaleway && !externalgrpc && !civo && !rancher
+// +build !gce,!aws,!azure,!kubemark,!alicloud,!magnum,!digitalocean,!clusterapi,!huaweicloud,!ionoscloud,!linode,!hetzner,!bizflycloud,!brightbox,!packet,!oci,!vultr,!tencentcloud,!scaleway,!externalgrpc,!civo,!rancher
 
 /*
 Copyright 2018 The Kubernetes Authors.
@@ -43,6 +43,7 @@ import (
 	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/oci"
 	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/ovhcloud"
 	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/packet"
+	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/rancher"
 	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/scaleway"
 	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/tencentcloud"
 	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/vultr"
@@ -76,6 +77,7 @@ var AvailableCloudProviders = []string{
 	cloudprovider.TencentcloudProviderName,
 	cloudprovider.CivoProviderName,
 	cloudprovider.ScalewayProviderName,
+	cloudprovider.RancherProviderName,
 }
 
 // DefaultCloudProvider is GCE.
@@ -133,6 +135,8 @@ func buildCloudProvider(opts config.AutoscalingOptions, do cloudprovider.NodeGro
 		return civo.BuildCivo(opts, do, rl)
 	case cloudprovider.ScalewayProviderName:
 		return scaleway.BuildScaleway(opts, do, rl)
+	case cloudprovider.RancherProviderName:
+		return rancher.BuildRancher(opts, do, rl)
 	}
 	return nil
 }

cluster-autoscaler/cloudprovider/builder/builder_rancher.go

@@ -0,0 +1,43 @@
+//go:build rancher
+// +build rancher
+
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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.
+*/
+
+package builder
+
+import (
+	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider"
+	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/rancher"
+	"k8s.io/autoscaler/cluster-autoscaler/config"
+)
+
+// AvailableCloudProviders supported by the cloud provider builder.
+var AvailableCloudProviders = []string{
+	cloudprovider.RancherProviderName,
+}
+
+// DefaultCloudProvider for rancher-only build is rancher.
+const DefaultCloudProvider = cloudprovider.RancherProviderName
+
+func buildCloudProvider(opts config.AutoscalingOptions, do cloudprovider.NodeGroupDiscoveryOptions, rl *cloudprovider.ResourceLimiter) cloudprovider.CloudProvider {
+	switch opts.CloudProviderName {
+	case cloudprovider.RancherProviderName:
+		return rancher.BuildRancher(opts, do, rl)
+	}
+
+	return nil
+}

cluster-autoscaler/cloudprovider/cloud_provider.go

@@ -80,6 +80,8 @@ const (
 	ExternalGrpcProviderName = "externalgrpc"
 	// CivoProviderName gets the provider name of civo
 	CivoProviderName = "civo"
+	// RancherProviderName gets the provider name of rancher
+	RancherProviderName = "rancher"
 )
 
 // CloudProvider contains configuration info and functions for interacting with

cluster-autoscaler/cloudprovider/rancher/OWNERS

@@ -0,0 +1,10 @@
+approvers:
+#- ctrox
+#- gajicdev
+#- pawelkuc
+#- thirdeyenick
+reviewers:
+#- ctrox
+#- gajicdev
+#- pawelkuc
+#- thirdeyenick

cluster-autoscaler/cloudprovider/rancher/README.md

@@ -0,0 +1,74 @@
+# Cluster Autoscaler for Rancher with RKE2
+
+This cluster autoscaler for Rancher scales nodes in clusters which use RKE2
+provisioning (Rancher v2.6+). It uses a combination of the Rancher API and the
+underlying cluster-api types of RKE2.
+
+## Configuration
+
+The `cluster-autoscaler` for Rancher needs a configuration file to work by
+using `--cloud-config` parameter. An up-to-date example can be found in
+[examples/config.yaml](./examples/config.yaml).
+
+### Permissions
+
+The Rancher server account provided in the `cloud-config` requires the
+following permissions on the Rancher server:
+
+* Get/Update of the `clusters.provisioning.cattle.io` resource to autoscale
+* List of `machines.cluster.x-k8s.io` in the namespace of the cluster resource
+
+## Running the Autoscaler
+
+The `cluster-autoscaler` can be run inside the RKE2 cluster, on the Rancher
+server cluster or on a completely separate machine. To run it outside the RKE2
+cluster, make sure to provide a kubeconfig with `--kubeconfig`.
+
+To start the autoscaler with the Rancher provider, the cloud provider needs to
+be specified:
+
+```bash
+cluster-autoscaler --cloud-provider=rancher --cloud-config=config.yaml
+```
+
+## Enabling Autoscaling
+
+In order for the autoscaler to function, the RKE2 cluster needs to be
+configured accordingly. The autoscaler works by adjusting the `quantity` of a
+`machinePool` dynamically. For the autoscaler to know the min/max size of a
+`machinePool` we need to set a few annotations using the
+`machineDeploymentAnnotations` field. That field has been chosen because
+updating it does not trigger a full rollout of a `machinePool`.
+
+```yaml
+apiVersion: provisioning.cattle.io/v1
+kind: Cluster
+spec:
+  rkeConfig:
+    machinePools:
+    - name: pool-1
+      quantity: 1
+      workerRole: true
+      machineDeploymentAnnotations:
+        cluster.provisioning.cattle.io/autoscaler-min-size: "1"
+        cluster.provisioning.cattle.io/autoscaler-max-size: "3"
+```
+
+Optionally in order to enable scaling a `machinePool` from and to 0 nodes, we
+need to add a few more annotations to let the autoscaler know, which resources
+a single node in a pool provides:
+
+```yaml
+apiVersion: provisioning.cattle.io/v1
+kind: Cluster
+spec:
+  rkeConfig:
+    machinePools:
+    - name: pool-1
+      machineDeploymentAnnotations:
+        cluster.provisioning.cattle.io/autoscaler-min-size: "0"
+        cluster.provisioning.cattle.io/autoscaler-max-size: "3"
+        cluster.provisioning.cattle.io/autoscaler-resource-cpu: "1"
+        cluster.provisioning.cattle.io/autoscaler-resource-ephemeral-storage: 50Gi
+        cluster.provisioning.cattle.io/autoscaler-resource-memory: 4Gi
+```

cluster-autoscaler/cloudprovider/rancher/examples/config.yaml

@@ -0,0 +1,9 @@
+# rancher server credentials
+url: https://rancher.example.org
+token: <rancher token>
+# name and namespace of the clusters.provisioning.cattle.io resource on the
+# rancher server
+clusterName: my-cluster
+clusterNamespace: fleet-default
+# optional, will be auto-discovered if not specified
+#clusterAPIVersion: v1alpha4

cluster-autoscaler/cloudprovider/rancher/provisioning.cattle.io/v1/rke.go

@@ -0,0 +1,88 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+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.
+*/
+
+package v1
+
+import (
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/intstr"
+)
+
+// RKEMachinePool configures a RKE machine pool
+type RKEMachinePool struct {
+	RKECommonNodeConfig `json:",inline"`
+
+	Paused                       bool                         `json:"paused,omitempty"`
+	EtcdRole                     bool                         `json:"etcdRole,omitempty"`
+	ControlPlaneRole             bool                         `json:"controlPlaneRole,omitempty"`
+	WorkerRole                   bool                         `json:"workerRole,omitempty"`
+	DrainBeforeDelete            bool                         `json:"drainBeforeDelete,omitempty"`
+	DrainBeforeDeleteTimeout     *metav1.Duration             `json:"drainBeforeDeleteTimeout,omitempty"`
+	NodeConfig                   *corev1.ObjectReference      `json:"machineConfigRef,omitempty" wrangler:"required"`
+	Name                         string                       `json:"name,omitempty" wrangler:"required"`
+	DisplayName                  string                       `json:"displayName,omitempty"`
+	Quantity                     *int32                       `json:"quantity,omitempty"`
+	RollingUpdate                *RKEMachinePoolRollingUpdate `json:"rollingUpdate,omitempty"`
+	MachineDeploymentLabels      map[string]string            `json:"machineDeploymentLabels,omitempty"`
+	MachineDeploymentAnnotations map[string]string            `json:"machineDeploymentAnnotations,omitempty"`
+	NodeStartupTimeout           *metav1.Duration             `json:"nodeStartupTimeout,omitempty"`
+	UnhealthyNodeTimeout         *metav1.Duration             `json:"unhealthyNodeTimeout,omitempty"`
+	MaxUnhealthy                 *string                      `json:"maxUnhealthy,omitempty"`
+	UnhealthyRange               *string                      `json:"unhealthyRange,omitempty"`
+	MachineOS                    string                       `json:"machineOS,omitempty"`
+}
+
+// RKEMachinePoolRollingUpdate configures the rolling update of a machine pool
+type RKEMachinePoolRollingUpdate struct {
+	// The maximum number of machines that can be unavailable during the update.
+	// Value can be an absolute number (ex: 5) or a percentage of desired
+	// machines (ex: 10%).
+	// Absolute number is calculated from percentage by rounding down.
+	// This can not be 0 if MaxSurge is 0.
+	// Defaults to 0.
+	// Example: when this is set to 30%, the old MachineSet can be scaled
+	// down to 70% of desired machines immediately when the rolling update
+	// starts. Once new machines are ready, old MachineSet can be scaled
+	// down further, followed by scaling up the new MachineSet, ensuring
+	// that the total number of machines available at all times
+	// during the update is at least 70% of desired machines.
+	// +optional
+	MaxUnavailable *intstr.IntOrString `json:"maxUnavailable,omitempty"`
+
+	// The maximum number of machines that can be scheduled above the
+	// desired number of machines.
+	// Value can be an absolute number (ex: 5) or a percentage of
+	// desired machines (ex: 10%).
+	// This can not be 0 if MaxUnavailable is 0.
+	// Absolute number is calculated from percentage by rounding up.
+	// Defaults to 1.
+	// Example: when this is set to 30%, the new MachineSet can be scaled
+	// up immediately when the rolling update starts, such that the total
+	// number of old and new machines do not exceed 130% of desired
+	// machines. Once old machines have been killed, new MachineSet can
+	// be scaled up further, ensuring that total number of machines running
+	// at any time during the update is at most 130% of desired machines.
+	// +optional
+	MaxSurge *intstr.IntOrString `json:"maxSurge,omitempty"`
+}
+
+// RKECommonNodeConfig contains common node configuration
+type RKECommonNodeConfig struct {
+	Labels                    map[string]string `json:"labels,omitempty"`
+	Taints                    []corev1.Taint    `json:"taints,omitempty"`
+	CloudCredentialSecretName string            `json:"cloudCredentialSecretName,omitempty"`
+}

cluster-autoscaler/cloudprovider/rancher/rancher_clusterapi.go

@@ -0,0 +1,57 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+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.
+*/
+
+package rancher
+
+import (
+	"fmt"
+
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/discovery"
+)
+
+const (
+	clusterAPIGroup               = "cluster.x-k8s.io"
+	machineDeleteAnnotationKey    = clusterAPIGroup + "/delete-machine"
+	machinePhaseProvisioning      = "Provisioning"
+	machinePhasePending           = "Pending"
+	machinePhaseDeleting          = "Deleting"
+	machineDeploymentNameLabelKey = clusterAPIGroup + "/deployment-name"
+	machineResourceName           = "machines"
+)
+
+func getAPIGroupPreferredVersion(client discovery.DiscoveryInterface, apiGroup string) (string, error) {
+	groupList, err := client.ServerGroups()
+	if err != nil {
+		return "", fmt.Errorf("failed to get ServerGroups: %v", err)
+	}
+
+	for _, group := range groupList.Groups {
+		if group.Name == apiGroup {
+			return group.PreferredVersion.Version, nil
+		}
+	}
+
+	return "", fmt.Errorf("failed to find API group %q", apiGroup)
+}
+
+func machineGVR(version string) schema.GroupVersionResource {
+	return schema.GroupVersionResource{
+		Group:    clusterAPIGroup,
+		Version:  version,
+		Resource: machineResourceName,
+	}
+}

cluster-autoscaler/cloudprovider/rancher/rancher_config.go

@@ -0,0 +1,46 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+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.
+*/
+
+package rancher
+
+import (
+	"fmt"
+	"os"
+
+	"gopkg.in/yaml.v2"
+)
+
+type cloudConfig struct {
+	URL               string `yaml:"url"`
+	Token             string `yaml:"token"`
+	ClusterName       string `yaml:"clusterName"`
+	ClusterNamespace  string `yaml:"clusterNamespace"`
+	ClusterAPIVersion string `yaml:"clusterAPIVersion"`
+}
+
+func newConfig(file string) (*cloudConfig, error) {
+	b, err := os.ReadFile(file)
+	if err != nil {
+		return nil, fmt.Errorf("unable to read cloud config file: %w", err)
+	}
+
+	config := &cloudConfig{}
+	if err := yaml.Unmarshal(b, config); err != nil {
+		return nil, fmt.Errorf("unable to unmarshal config file: %w", err)
+	}
+
+	return config, nil
+}