feat: each node pool can now have different init configs

cluster-autoscaler/cloudprovider/hetzner/README.md

@@ -10,6 +10,38 @@ The cluster autoscaler for Hetzner Cloud scales worker nodes.
 
 `HCLOUD_IMAGE` Defaults to `ubuntu-20.04`, @see https://docs.hetzner.cloud/#images. You can also use an image ID here (e.g. `15512617`), or a label selector associated with a custom snapshot (e.g. `customized_ubuntu=true`). The most recent snapshot will be used in the latter case.
 
+`HCLOUD_CLUSTER_CONFIG` This is the new format replacing 
+ * `HCLOUD_CLOUD_INIT` 
+ * `HCLOUD_IMAGE` 
+
+ Base64 encoded JSON according to the following structure
+
+```json
+{
+    "imagesForArch": { // These should be the same format as HCLOUD_IMAGE
+        "arm64": "", 
+        "amd64": ""
+    },
+    "nodeConfigs": {
+        "pool1": { // This equals the pool name. Required for each pool that you have
+            "cloudInit": "", // HCLOUD_CLOUD_INIT make sure it isn't base64 encoded twice ;]
+            "labels": {
+                "node.kubernetes.io/role": "autoscaler-node"
+            },
+            "taints": 
+            [
+                {
+                    "key": "node.kubernetes.io/role",
+                    "value": "autoscaler-node",
+                    "effect": "NoExecute",
+                }
+            ]
+        }
+    }
+}
+```
+
+
 `HCLOUD_NETWORK` Default empty , The name of the network that is used in the cluster , @see https://docs.hetzner.cloud/#networks
 
 `HCLOUD_FIREWALL` Default empty , The name of the firewall that is used in the cluster , @see https://docs.hetzner.cloud/#firewalls

cluster-autoscaler/cloudprovider/hetzner/hetzner_cloud_provider.go

@@ -191,9 +191,12 @@ func BuildHetzner(_ config.AutoscalingOptions, do cloudprovider.NodeGroupDiscove
 		klog.Fatalf("Failed to create Hetzner cloud provider: %v", err)
 	}
 
+	if manager.clusterConfig.IsUsingNewFormat && len(manager.clusterConfig.NodeConfigs) == 0 {
+		klog.Fatalf("No cluster config present provider: %v", err)
+	}
+
 	validNodePoolName := regexp.MustCompile(`^[a-z0-9A-Z]+[a-z0-9A-Z\-\.\_]*[a-z0-9A-Z]+$|^[a-z0-9A-Z]{1}$`)
 	clusterUpdateLock := sync.Mutex{}
-
 	for _, nodegroupSpec := range do.NodeGroupSpecs {
 		spec, err := createNodePoolSpec(nodegroupSpec)
 		if err != nil {
@@ -206,6 +209,13 @@ func BuildHetzner(_ config.AutoscalingOptions, do cloudprovider.NodeGroupDiscove
 			klog.Fatalf("Failed to get servers for for node pool %s error: %v", nodegroupSpec, err)
 		}
 
+		if manager.clusterConfig.IsUsingNewFormat {
+			_, ok := manager.clusterConfig.NodeConfigs[spec.name]
+			if !ok {
+				klog.Fatalf("No node config present for node group id `%s` error: %v", spec.name, err)
+			}
+		}
+
 		manager.nodeGroups[spec.name] = &hetznerNodeGroup{
 			manager:            manager,
 			id:                 spec.name,

cluster-autoscaler/cloudprovider/hetzner/hetzner_manager.go

@@ -19,6 +19,7 @@ package hetzner
 import (
 	"context"
 	"encoding/base64"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"net/http"
@@ -45,8 +46,7 @@ type hetznerManager struct {
 	client           *hcloud.Client
 	nodeGroups       map[string]*hetznerNodeGroup
 	apiCallContext   context.Context
-	cloudInit        string
-	image            string
+	clusterConfig    *ClusterConfig
 	sshKey           *hcloud.SSHKey
 	network          *hcloud.Network
 	firewall         *hcloud.Firewall
@@ -57,6 +57,33 @@ type hetznerManager struct {
 	cachedServers    *serversCache
 }
 
+// ClusterConfig holds the configuration for all the nodepools
+type ClusterConfig struct {
+	ImagesForArch    ImageList
+	NodeConfigs      map[string]*NodeConfig
+	IsUsingNewFormat bool
+	LegacyConfig     LegacyConfig
+}
+
+// ImageList holds the image id/names for the different architectures
+type ImageList struct {
+	Arm64 string
+	Amd64 string
+}
+
+// NodeConfig holds the configuration for a single nodepool
+type NodeConfig struct {
+	CloudInit string
+	Taints    []apiv1.Taint
+	Labels    map[string]string
+}
+
+// LegacyConfig holds the configuration in the legacy format
+type LegacyConfig struct {
+	CloudInit string
+	ImageName string
+}
+
 func newManager() (*hetznerManager, error) {
 	token := os.Getenv("HCLOUD_TOKEN")
 	if token == "" {
@@ -71,19 +98,44 @@ func newManager() (*hetznerManager, error) {
 	)
 
 	ctx := context.Background()
+	var err error
 
+	clusterConfigBase64 := os.Getenv("HCLOUD_CLUSTER_CONFIG")
 	cloudInitBase64 := os.Getenv("HCLOUD_CLOUD_INIT")
-	if cloudInitBase64 == "" {
-		return nil, errors.New("`HCLOUD_CLOUD_INIT` is not specified")
+
+	if clusterConfigBase64 == "" && cloudInitBase64 == "" {
+		return nil, errors.New("`HCLOUD_CLUSTER_CONFIG` or `HCLOUD_CLOUD_INIT` is not specified")
 	}
-	cloudInit, err := base64.StdEncoding.DecodeString(cloudInitBase64)
-	if err != nil {
-		return nil, fmt.Errorf("failed to parse cloud init error: %s", err)
+	var clusterConfig *ClusterConfig = &ClusterConfig{}
+
+	if clusterConfigBase64 != "" {
+		clusterConfig.IsUsingNewFormat = true
 	}
 
-	imageName := os.Getenv("HCLOUD_IMAGE")
-	if imageName == "" {
-		imageName = "ubuntu-20.04"
+	if clusterConfig.IsUsingNewFormat {
+		clusterConfigEnv, err := base64.StdEncoding.DecodeString(clusterConfigBase64)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse cluster config error: %s", err)
+		}
+		err = json.Unmarshal(clusterConfigEnv, &clusterConfig)
+		if err != nil {
+			return nil, fmt.Errorf("failed to unmarshal cluster config JSON: %s", err)
+		}
+	}
+
+	if !clusterConfig.IsUsingNewFormat {
+		cloudInit, err := base64.StdEncoding.DecodeString(cloudInitBase64)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse cloud init error: %s", err)
+		}
+
+		imageName := os.Getenv("HCLOUD_IMAGE")
+		if imageName == "" {
+			imageName = "ubuntu-20.04"
+		}
+
+		clusterConfig.LegacyConfig.CloudInit = string(cloudInit)
+		clusterConfig.LegacyConfig.ImageName = imageName
 	}
 
 	publicIPv4 := true
@@ -141,15 +193,14 @@ func newManager() (*hetznerManager, error) {
 	m := &hetznerManager{
 		client:           client,
 		nodeGroups:       make(map[string]*hetznerNodeGroup),
-		cloudInit:        string(cloudInit),
-		image:            imageName,
 		sshKey:           sshKey,
 		network:          network,
 		firewall:         firewall,
 		createTimeout:    createTimeout,
 		apiCallContext:   ctx,
 		publicIPv4:       publicIPv4,
 		publicIPv6:       publicIPv6,
+		clusterConfig:    clusterConfig,
 		cachedServerType: newServerTypeCache(ctx, client),
 		cachedServers:    newServersCache(ctx, client),
 	}

cluster-autoscaler/cloudprovider/hetzner/hetzner_node_group.go

@@ -19,6 +19,7 @@ package hetzner
 import (
 	"context"
 	"fmt"
+	"maps"
 	"math/rand"
 	"strings"
 	"sync"
@@ -241,6 +242,16 @@ func (n *hetznerNodeGroup) TemplateNodeInfo() (*schedulerframework.NodeInfo, err
 	}
 	node.Labels = cloudprovider.JoinStringMaps(node.Labels, nodeGroupLabels)
 
+	if n.manager.clusterConfig.IsUsingNewFormat && n.id != drainingNodePoolId {
+		for _, taint := range n.manager.clusterConfig.NodeConfigs[n.id].Taints {
+			node.Spec.Taints = append(node.Spec.Taints, apiv1.Taint{
+				Key:    taint.Key,
+				Value:  taint.Value,
+				Effect: taint.Effect,
+			})
+		}
+	}
+
 	nodeInfo := schedulerframework.NewNodeInfo(cloudprovider.BuildKubeProxy(n.id))
 	nodeInfo.SetNode(&node)
 
@@ -325,14 +336,23 @@ func buildNodeGroupLabels(n *hetznerNodeGroup) (map[string]string, error) {
 	if err != nil {
 		return nil, err
 	}
+	klog.V(4).Infof("Build node group label for %s", n.id)
 
-	return map[string]string{
+	labels := map[string]string{
 		apiv1.LabelInstanceType:      n.instanceType,
 		apiv1.LabelTopologyRegion:    n.region,
 		apiv1.LabelArchStable:        archLabel,
 		"csi.hetzner.cloud/location": n.region,
 		nodeGroupLabel:               n.id,
-	}, nil
+	}
+
+	if n.manager.clusterConfig.IsUsingNewFormat && n.id != drainingNodePoolId {
+		maps.Copy(labels, n.manager.clusterConfig.NodeConfigs[n.id].Labels)
+	}
+
+	klog.V(4).Infof("%s nodegroup labels: %s", n.id, labels)
+
+	return labels, nil
 }
 
 func getMachineTypeResourceList(m *hetznerManager, instanceType string) (apiv1.ResourceList, error) {
@@ -392,10 +412,16 @@ func createServer(n *hetznerNodeGroup) error {
 		return err
 	}
 
+	cloudInit := n.manager.clusterConfig.LegacyConfig.CloudInit
+
+	if n.manager.clusterConfig.IsUsingNewFormat {
+		cloudInit = n.manager.clusterConfig.NodeConfigs[n.id].CloudInit
+	}
+
 	StartAfterCreate := true
 	opts := hcloud.ServerCreateOpts{
 		Name:             newNodeName(n),
-		UserData:         n.manager.cloudInit,
+		UserData:         cloudInit,
 		Location:         &hcloud.Location{Name: n.region},
 		ServerType:       serverType,
 		Image:            image,
@@ -443,7 +469,18 @@ func createServer(n *hetznerNodeGroup) error {
 // server.
 func findImage(n *hetznerNodeGroup, serverType *hcloud.ServerType) (*hcloud.Image, error) {
 	// Select correct image based on server type architecture
-	image, _, err := n.manager.client.Image.GetForArchitecture(context.TODO(), n.manager.image, serverType.Architecture)
+	imageName := n.manager.clusterConfig.LegacyConfig.ImageName
+	if n.manager.clusterConfig.IsUsingNewFormat {
+		if serverType.Architecture == hcloud.ArchitectureARM {
+			imageName = n.manager.clusterConfig.ImagesForArch.Arm64
+		}
+
+		if serverType.Architecture == hcloud.ArchitectureX86 {
+			imageName = n.manager.clusterConfig.ImagesForArch.Amd64
+		}
+	}
+
+	image, _, err := n.manager.client.Image.GetForArchitecture(context.TODO(), imageName, serverType.Architecture)
 	if err != nil {
 		// Keep looking for label if image was not found by id or name
 		if !strings.HasPrefix(err.Error(), "image not found") {
@@ -462,12 +499,12 @@ func findImage(n *hetznerNodeGroup, serverType *hcloud.ServerType) (*hcloud.Imag
 		Sort:         []string{"created:desc"},
 		Architecture: []hcloud.Architecture{serverType.Architecture},
 		ListOpts: hcloud.ListOpts{
-			LabelSelector: n.manager.image,
+			LabelSelector: imageName,
 		},
 	})
 
 	if err != nil || len(images) == 0 {
-		return nil, fmt.Errorf("unable to find image %s with architecture %s: %v", n.manager.image, serverType.Architecture, err)
+		return nil, fmt.Errorf("unable to find image %s with architecture %s: %v", imageName, serverType.Architecture, err)
 	}
 
 	return images[0], nil