Fix Autoscaling for worker nodes with invalid ProviderID

This change fixes a bug that arises when the user's cluster includes worker nodes not from Hetzner Cloud, such as a Hetzner Dedicated server or any server resource other than Hetzner. It also corrects the behavior when a server has been physically deleted from Hetzner Cloud.

Signed-off-by: Maksim Paskal <[email protected]>

cluster-autoscaler/cloudprovider/hetzner/hetzner_servers_cache.go

@@ -18,7 +18,6 @@ package hetzner
 
 import (
 	"context"
-	"errors"
 	"strconv"
 	"sync"
 	"time"
@@ -136,7 +135,8 @@ func (m *serversCache) getServer(nodeIdOrName string) (*hcloud.Server, error) {
 		}
 	}
 
-	return nil, errors.New("server not found")
+	// return nil if server not found
+	return nil, nil
 }
 
 func (m *serversCache) getServersByNodeGroupName(nodeGroup string) ([]*hcloud.Server, error) {

cluster-autoscaler/cloudprovider/hetzner/hetzner_servers_cache_test.go

@@ -70,6 +70,7 @@ func TestServersCache(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, "test2", foundservers.Name)
 
-	_, err = c.getServer("test3")
-	require.Error(t, err)
+	server, err := c.getServer("test3")
+	require.Nil(t, server)
+	require.NoError(t, err)
 }