Add Rancher as a cloud provider

cluster-autoscaler/README.md

@@ -20,12 +20,13 @@ You should also take a look at the notes and "gotchas" for your specific cloud p
 * [CloudStack](./cloudprovider/cloudstack/README.md)
 * [HuaweiCloud](./cloudprovider/huaweicloud/README.md)
 * [Hetzner](./cloudprovider/hetzner/README.md)
-* [Packet](./cloudprovider/packet/README.md#notes) 
+* [Packet](./cloudprovider/packet/README.md#notes)
 * [IonosCloud](./cloudprovider/ionoscloud/README.md)
 * [OVHcloud](./cloudprovider/ovhcloud/README.md)
 * [Linode](./cloudprovider/linode/README.md)
 * [ClusterAPI](./cloudprovider/clusterapi/README.md)
 * [BizflyCloud](./cloudprovider/bizflycloud/README.md)
+* [Rancher](./cloudprovider/rancher/README.md)
 
 # Releases
 
@@ -159,3 +160,4 @@ Supported cloud providers:
 * Linode https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/linode/README.md
 * Hetzner https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/hetzner/README.md
 * Cluster API https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/clusterapi/README.md
+* Rancher https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/rancher/README.md

cluster-autoscaler/cloudprovider/builder/builder_all.go

@@ -1,4 +1,4 @@
-// +build !gce,!aws,!azure,!kubemark,!alicloud,!magnum,!digitalocean,!clusterapi,!huaweicloud,!ionoscloud,!linode,!hetzner,!bizflycloud
+// +build !gce,!aws,!azure,!kubemark,!alicloud,!magnum,!digitalocean,!clusterapi,!huaweicloud,!ionoscloud,!linode,!hetzner,!bizflycloud,!rancher
 
 /*
 Copyright 2018 The Kubernetes Authors.
@@ -37,6 +37,7 @@ import (
 	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/magnum"
 	"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/config"
 )
 
@@ -58,6 +59,7 @@ var AvailableCloudProviders = []string{
 	cloudprovider.IonoscloudProviderName,
 	cloudprovider.LinodeProviderName,
 	cloudprovider.BizflyCloudProviderName,
+	cloudprovider.RancherProviderName,
 }
 
 // DefaultCloudProvider is GCE.
@@ -99,6 +101,8 @@ func buildCloudProvider(opts config.AutoscalingOptions, do cloudprovider.NodeGro
 		return ionoscloud.BuildIonosCloud(opts, do, rl)
 	case cloudprovider.LinodeProviderName:
 		return linode.BuildLinode(opts, do, rl)
+	case cloudprovider.RancherProviderName:
+		return rancher.BuildRancher(opts, do, rl)
 	}
 	return nil
 }

cluster-autoscaler/cloudprovider/builder/builder_rancher.go

@@ -0,0 +1,42 @@
+// +build rancher
+
+/*
+Copyright 2021 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 rancher provider builder.
+var AvailableCloudProviders = []string{
+	cloudprovider.RancherProviderName,
+}
+
+// DefaultCloudProvider for do-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

@@ -62,6 +62,8 @@ const (
 	OVHcloudProviderName = "ovhcloud"
 	// LinodeProviderName gets the provider name of linode
 	LinodeProviderName = "linode"
+	// RancherProviderName gets the provider name of rancher
+	RancherProviderName = "rancher"
 )
 
 // CloudProvider contains configuration info and functions for interacting with

cluster-autoscaler/cloudprovider/rancher/README.md

@@ -0,0 +1,54 @@
+# Cluster Autoscaler for Rancher
+
+The cluster autoscaler for Rancher scales nodes within any specified Rancher Kubernetes Engine cluster's node pool.
+
+# Requirements
+
+Rancher version >= 2.5.6
+
+# Configuration
+
+The cluster-autoscaler for Rancher needs a configuration file to work by using --cloud-config parameter.
+
+Here an [example](examples/autoscaler-config-example.yaml).
+
+```yaml
+apiVersion: v1
+kind: Secret
+metadata:
+  name: cluster-autoscaler-cloud-config
+  namespace: kube-system
+type: Opaque
+stringData:
+  cloud-config: |-
+    [Global]
+    url=https://rancherapi.com/v3
+    access=your-token
+    secret=your-secret
+    cluster-id=c-abcdef
+  autoscaler_node_arg: "2:6:c-abcdef:np-abcde" # Your NodePool ID
+```
+
+You have to create a new API Key from your Rancher Dashboard to get the `access` and `secret` values to use the Autoscaler.
+
+# Development
+
+Make sure you're inside the root path of the [autoscaler repository](https://github.com/kubernetes/autoscaler)
+
+1.) Build the `cluster-autoscaler` binary:
+
+```
+make build-in-docker
+```
+
+2.) Build the docker image:
+
+```
+docker build -t rancher/cluster-autoscaler:dev .
+```
+
+3.) Push the docker image to Docker hub:
+
+```
+docker push rancher/cluster-autoscaler:dev
+```

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

@@ -0,0 +1,14 @@
+apiVersion: v1
+kind: Secret
+metadata:
+  name: cluster-autoscaler-cloud-config
+  namespace: kube-system
+type: Opaque
+stringData:
+  cloud-config: |-
+    [Global]
+    url=https://rancherapi.com/v3
+    access=token-abcdef
+    secret=ksjdhfiusdhfkjsdfhisudhfnskjdfhskjdfhksdjfhksjdfhksdjf
+    cluster-id=c-abcdef
+  autoscaler_node_arg: "2:6:c-abcdef:np-abcde"

cluster-autoscaler/cloudprovider/rancher/examples/autoscaler-noconfig-template.txt

@@ -0,0 +1,118 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: cluster-autoscaler-role
+rules:
+  - apiGroups: [""]
+    resources: ["events", "endpoints"]
+    verbs: ["create", "patch"]
+  - apiGroups: [""]
+    resources: ["pods/eviction"]
+    verbs: ["create"]
+  - apiGroups: [""]
+    resources: ["pods/status"]
+    verbs: ["update"]
+  - apiGroups: [""]
+    resources: ["endpoints"]
+    resourceNames: ["cluster-autoscaler"]
+    verbs: ["get", "update"]
+  - apiGroups: [""]
+    resources: ["nodes"]
+    verbs: ["watch", "list", "get", "update"]
+  - apiGroups: [""]
+    resources:
+      - "pods"
+      - "services"
+      - "replicationcontrollers"
+      - "persistentvolumeclaims"
+      - "persistentvolumes"
+    verbs: ["watch", "list", "get"]
+  - apiGroups: ["batch"]
+    resources: ["jobs"]
+    verbs: ["watch", "list", "get"]
+  - apiGroups: ["policy"]
+    resources: ["poddisruptionbudgets"]
+    verbs: ["watch", "list"]
+  - apiGroups: ["apps"]
+    resources: ["daemonsets", "replicasets", "statefulsets"]
+    verbs: ["watch", "list", "get"]
+  - apiGroups: ["storage.k8s.io"]
+    resources: ["storageclasses", "csinodes"]
+    verbs: ["watch", "list", "get"]
+  - apiGroups: [""]
+    resources: ["configmaps"]
+    verbs: ["create","list","watch"]
+  - apiGroups: [""]
+    resources: ["configmaps"]
+    resourceNames: ["cluster-autoscaler-status", "cluster-autoscaler-priority-expander"]
+    verbs: ["delete", "get", "update"]
+  - apiGroups: ["coordination.k8s.io"]
+    resources: ["leases"]
+    verbs: ["watch", "list", "get", "create", "update", "patch", "delete", "deletecollection"]
+
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: cluster-autoscaler-rolebinding
+  namespace: kube-system
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: cluster-autoscaler-role
+subjects:
+  - kind: ServiceAccount
+    name: cluster-autoscaler-account
+    namespace: kube-system
+
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: cluster-autoscaler-account
+  namespace: kube-system
+
+---
+kind: Deployment
+apiVersion: apps/v1
+metadata:
+  name: cluster-autoscaler
+  namespace: kube-system
+  labels:
+    app: cluster-autoscaler
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: cluster-autoscaler
+  template:
+    metadata:
+      namespace: kube-system
+      labels:
+        app: cluster-autoscaler
+    spec:
+      serviceAccountName: cluster-autoscaler-account
+      containers:
+        - name: cluster-autoscaler
+          image: us.gcr.io/gns-hosting-dev/cluster-autoscaler-amd64:{{ env "TAG" }}
+          imagePullPolicy: Always
+          command:
+            - ./cluster-autoscaler
+            - --alsologtostderr
+            - --cloud-config=/config/cloud-config
+            - --cloud-provider=rancher
+            - --nodes=$(NODE_ARG)
+          volumeMounts:
+            - name: cloud-config
+              mountPath: /config
+              readOnly: true
+          env:
+            - name: NODE_ARG
+              valueFrom:
+                secretKeyRef:
+                  name: cluster-autoscaler-cloud-config
+                  key: autoscaler_node_arg
+      volumes:
+        - name: cloud-config
+          secret:
+            secretName: cluster-autoscaler-cloud-config