Default min/max sizes for Azure VMSSs

cluster-autoscaler/FAQ.md

@@ -759,7 +759,7 @@ The following startup parameters are supported for cluster autoscaler:
 | `ok-total-unready-count` | Number of allowed unready nodes, irrespective of max-total-unready-percentage  | 3
 | `max-node-provision-time` | Maximum time CA waits for node to be provisioned | 15 minutes
 | `nodes` | sets min,max size and other configuration data for a node group in a format accepted by cloud provider. Can be used multiple times. Format: \<min>:\<max>:<other...> | ""
-| `node-group-auto-discovery` | One or more definition(s) of node group auto-discovery.<br>A definition is expressed `<name of discoverer>:[<key>[=<value>]]`<br>The `aws`, `gce`, and `azure` cloud providers are currently supported. AWS matches by ASG tags, e.g. `asg:tag=tagKey,anotherTagKey`<br>GCE matches by IG name prefix, and requires you to specify min and max nodes per IG, e.g. `mig:namePrefix=pfx,min=0,max=10`<br> Azure matches by tags on VMSS, e.g. `label:foo=bar`, and will auto-detect `min` and `max` tags on the VMSS to set scaling limits.<br>Can be used multiple times | ""
+| `node-group-auto-discovery` | One or more definition(s) of node group auto-discovery.<br>A definition is expressed `<name of discoverer>:[<key>[=<value>]]`<br>The `aws`, `gce`, and `azure` cloud providers are currently supported. AWS matches by ASG tags, e.g. `asg:tag=tagKey,anotherTagKey`<br>GCE matches by IG name prefix, and requires you to specify min and max nodes per IG, e.g. `mig:namePrefix=pfx,min=0,max=10`<br> Azure matches by VMSS tags, similar to AWS. And you can optionally specify a default min and max size for VMSSs, e.g. `label:tag=tagKey,anotherTagKey=bar,min=0,max=600`.<br>Can be used multiple times | ""
 | `emit-per-nodegroup-metrics` | If true, emit per node group metrics. | false
 | `estimator` | Type of resource estimator to be used in scale up | binpacking
 | `expander` | Type of node group expander to be used in scale up.  | random

cluster-autoscaler/cloudprovider/azure/azure_autodiscovery.go

@@ -18,18 +18,26 @@ package azure
 
 import (
 	"fmt"
-	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider"
+	"strconv"
 	"strings"
+
+	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider"
 )
 
 const (
-	autoDiscovererTypeLabel = "label"
+	autoDiscovererTypeLabel       = "label"
+	vmssAutoDiscovererKeyMinNodes = "min"
+	vmssAutoDiscovererKeyMaxNodes = "max"
 )
 
 // A labelAutoDiscoveryConfig specifies how to auto-discover Azure node groups.
 type labelAutoDiscoveryConfig struct {
 	// Key-values to match on.
 	Selector map[string]string
+	// MinSize specifies the minimum size for all VMSSs that match Selector.
+	MinSize *int
+	// MazSize specifies the maximum size for all VMSSs that match Selector.
+	MaxSize *int
 }
 
 // ParseLabelAutoDiscoverySpecs returns any provided NodeGroupAutoDiscoverySpecs
@@ -70,34 +78,63 @@ func parseLabelAutoDiscoverySpec(spec string) (labelAutoDiscoveryConfig, error)
 		if k == "" || v == "" {
 			return cfg, fmt.Errorf("empty value not allowed in key=value tag pairs")
 		}
-		cfg.Selector[k] = v
+
+		switch k {
+		case vmssAutoDiscovererKeyMinNodes:
+			minSize, err := strconv.Atoi(v)
+			if err != nil || minSize < 0 {
+				return cfg, fmt.Errorf("invalid minimum nodes: %s", v)
+			}
+			cfg.MinSize = &minSize
+		case vmssAutoDiscovererKeyMaxNodes:
+			maxSize, err := strconv.Atoi(v)
+			if err != nil || maxSize < 0 {
+				return cfg, fmt.Errorf("invalid maximum nodes: %s", v)
+			}
+			cfg.MaxSize = &maxSize
+		default:
+			cfg.Selector[k] = v
+		}
+	}
+	if cfg.MaxSize != nil && cfg.MinSize != nil && *cfg.MaxSize < *cfg.MinSize {
+		return cfg, fmt.Errorf("maximum size %d must be greater than or equal to minimum size %d", *cfg.MaxSize, *cfg.MinSize)
 	}
 	return cfg, nil
 }
 
-func matchDiscoveryConfig(labels map[string]*string, configs []labelAutoDiscoveryConfig) bool {
+// returns true if the VMSS's tags match the autodiscovery configs
+// if there are multiple min/max sizes defined, return the highest min value and the lowest max value
+func matchDiscoveryConfig(labels map[string]*string, configs []labelAutoDiscoveryConfig) (bool, int, int) {
 	if len(configs) == 0 {
-		return false
+		return false, 0, 0
 	}
+	minSize := -1
+	maxSize := -1
 
 	for _, c := range configs {
 		if len(c.Selector) == 0 {
-			return false
+			return false, 0, 0
 		}
 
 		for k, v := range c.Selector {
 			value, ok := labels[k]
 			if !ok {
-				return false
+				return false, 0, 0
 			}
 
 			if len(v) > 0 {
 				if value == nil || *value != v {
-					return false
+					return false, 0, 0
 				}
 			}
 		}
+		if c.MinSize != nil && minSize < *c.MinSize {
+			minSize = *c.MinSize
+		}
+		if c.MaxSize != nil && (maxSize == -1 || maxSize > *c.MaxSize) {
+			maxSize = *c.MaxSize
+		}
 	}
 
-	return true
+	return true, minSize, maxSize
 }

cluster-autoscaler/cloudprovider/azure/azure_autodiscovery_test.go

@@ -17,12 +17,15 @@ limitations under the License.
 package azure
 
 import (
+	"testing"
+
 	"github.com/stretchr/testify/assert"
 	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider"
-	"testing"
 )
 
 func TestParseLabelAutoDiscoverySpecs(t *testing.T) {
+	minVal := 1
+	maxVal := 2
 	testCases := []struct {
 		name        string
 		specs       []string
@@ -46,7 +49,7 @@ func TestParseLabelAutoDiscoverySpecs(t *testing.T) {
 			expectedErr: true,
 		},
 		{
-			name:        "InvalidAutoDiscoerLabel",
+			name:        "InvalidAutoDiscoverLabel",
 			specs:       []string{"invalid:test-tag=test-value,another-test-tag"},
 			expectedErr: true,
 		},
@@ -60,6 +63,70 @@ func TestParseLabelAutoDiscoverySpecs(t *testing.T) {
 			specs:       []string{"label:=test-val"},
 			expectedErr: true,
 		},
+		{
+			name: "ValidSpecWithSizes",
+			specs: []string{
+				"label:cluster-autoscaler-enabled=true,cluster-autoscaler-name=fake-cluster,min=1,max=2",
+				"label:test-tag=test-value,another-test-tag=another-test-value,min=1,max=2",
+			},
+			expected: []labelAutoDiscoveryConfig{
+				{Selector: map[string]string{"cluster-autoscaler-enabled": "true", "cluster-autoscaler-name": "fake-cluster"}, MinSize: &minVal, MaxSize: &maxVal},
+				{Selector: map[string]string{"test-tag": "test-value", "another-test-tag": "another-test-value"}, MinSize: &minVal, MaxSize: &maxVal},
+			},
+		},
+		{
+			name: "ValidSpecWithSizesOnlyMax",
+			specs: []string{
+				"label:cluster-autoscaler-enabled=true,max=2",
+			},
+			expected: []labelAutoDiscoveryConfig{
+				{Selector: map[string]string{"cluster-autoscaler-enabled": "true"}, MaxSize: &maxVal},
+			},
+		},
+		{
+			name: "ValidSpecWithSizesOnlyMin",
+			specs: []string{
+				"label:cluster-autoscaler-enabled=true,min=1",
+			},
+			expected: []labelAutoDiscoveryConfig{
+				{Selector: map[string]string{"cluster-autoscaler-enabled": "true"}, MinSize: &minVal},
+			},
+		},
+		{
+			name: "NonIntegerMin",
+			specs: []string{
+				"label:cluster-autoscaler-enabled=true,min=random,max=2",
+			},
+			expectedErr: true,
+		},
+		{
+			name: "NegativeMin",
+			specs: []string{
+				"label:cluster-autoscaler-enabled=true,min=-5,max=2",
+			},
+			expectedErr: true,
+		},
+		{
+			name: "NonIntegerMax",
+			specs: []string{
+				"label:cluster-autoscaler-enabled=true,min=1,max=random",
+			},
+			expectedErr: true,
+		},
+		{
+			name: "NegativeMax",
+			specs: []string{
+				"label:cluster-autoscaler-enabled=true,min=1,max=-5",
+			},
+			expectedErr: true,
+		},
+		{
+			name: "LowerMaxThanMin",
+			specs: []string{
+				"label:cluster-autoscaler-enabled=true,min=5,max=1",
+			},
+			expectedErr: true,
+		},
 	}
 
 	for _, tc := range testCases {

cluster-autoscaler/cloudprovider/azure/azure_manager.go

@@ -293,12 +293,14 @@ func (m *AzureManager) getFilteredScaleSets(filter []labelAutoDiscoveryConfig) (
 
 	var nodeGroups []cloudprovider.NodeGroup
 	for _, scaleSet := range vmssList {
+		var found bool
+		var cfgMinSize, cfgMaxSize int
 		if len(filter) > 0 {
 			if scaleSet.Tags == nil || len(scaleSet.Tags) == 0 {
 				continue
 			}
 
-			if !matchDiscoveryConfig(scaleSet.Tags, filter) {
+			if found, cfgMinSize, cfgMaxSize = matchDiscoveryConfig(scaleSet.Tags, filter); !found {
 				continue
 			}
 		}
@@ -316,6 +318,8 @@ func (m *AzureManager) getFilteredScaleSets(filter []labelAutoDiscoveryConfig) (
 				klog.Warningf("ignoring vmss %q because of invalid minimum size specified for vmss: %s", *scaleSet.Name, err)
 				continue
 			}
+		} else if cfgMinSize >= 0 {
+			spec.MinSize = cfgMinSize
 		} else {
 			klog.Warningf("ignoring vmss %q because of no minimum size specified for vmss", *scaleSet.Name)
 			continue
@@ -331,12 +335,14 @@ func (m *AzureManager) getFilteredScaleSets(filter []labelAutoDiscoveryConfig) (
 				klog.Warningf("ignoring vmss %q because of invalid maximum size specified for vmss: %s", *scaleSet.Name, err)
 				continue
 			}
+		} else if cfgMaxSize >= 0 {
+			spec.MaxSize = cfgMaxSize
 		} else {
 			klog.Warningf("ignoring vmss %q because of no maximum size specified for vmss", *scaleSet.Name)
 			continue
 		}
 		if spec.MaxSize < spec.MinSize {
-			klog.Warningf("ignoring vmss %q because of maximum size must be greater than minimum size: max=%d < min=%d", *scaleSet.Name, spec.MaxSize, spec.MinSize)
+			klog.Warningf("ignoring vmss %q because of maximum size must be greater than or equal to minimum size: max=%d < min=%d", *scaleSet.Name, spec.MaxSize, spec.MinSize)
 			continue
 		}
 

cluster-autoscaler/cloudprovider/azure/azure_manager_test.go

@@ -667,6 +667,53 @@ func TestGetFilteredAutoscalingGroupsVmss(t *testing.T) {
 	assert.True(t, assert.ObjectsAreEqualValues(expectedAsgs, asgs), "expected %#v, but found: %#v", expectedAsgs, asgs)
 }
 
+func TestGetFilteredAutoscalingGroupsVmssWithConfiguredSizes(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	vmssName := "test-vmss"
+	vmssTag := "fake-tag"
+	vmssTagValue := "fake-value"
+	vmssTag2 := "fake-tag2"
+	vmssTagValue2 := "fake-value2"
+	minVal := 2
+	maxVal := 4
+
+	ngdo := cloudprovider.NodeGroupDiscoveryOptions{
+		NodeGroupAutoDiscoverySpecs: []string{
+			fmt.Sprintf("label:%s=%s,min=2,max=5", vmssTag, vmssTagValue),
+			fmt.Sprintf("label:%s=%s,min=1,max=4", vmssTag2, vmssTagValue2),
+		},
+	}
+
+	manager := newTestAzureManager(t)
+	expectedScaleSets := []compute.VirtualMachineScaleSet{fakeVMSSWithTags(vmssName, map[string]*string{vmssTag: &vmssTagValue, vmssTag2: &vmssTagValue2})}
+	mockVMSSClient := mockvmssclient.NewMockInterface(ctrl)
+	mockVMSSClient.EXPECT().List(gomock.Any(), manager.config.ResourceGroup).Return(expectedScaleSets, nil).AnyTimes()
+	manager.azClient.virtualMachineScaleSetsClient = mockVMSSClient
+	err := manager.forceRefresh()
+	assert.NoError(t, err)
+
+	specs, err := ParseLabelAutoDiscoverySpecs(ngdo)
+	assert.NoError(t, err)
+
+	asgs, err := manager.getFilteredNodeGroups(specs)
+	assert.NoError(t, err)
+	expectedAsgs := []cloudprovider.NodeGroup{&ScaleSet{
+		azureRef: azureRef{
+			Name: vmssName,
+		},
+		minSize:                minVal,
+		maxSize:                maxVal,
+		manager:                manager,
+		enableForceDelete:      manager.config.EnableForceDelete,
+		curSize:                3,
+		sizeRefreshPeriod:      manager.azureCache.refreshInterval,
+		instancesRefreshPeriod: defaultVmssInstancesRefreshPeriod,
+	}}
+	assert.True(t, assert.ObjectsAreEqualValues(expectedAsgs, asgs), "expected %#v, but found: %#v", expectedAsgs, asgs)
+}
+
 func TestGetFilteredAutoscalingGroupsWithInvalidVMType(t *testing.T) {
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()

cluster-autoscaler/main.go

@@ -155,8 +155,9 @@ var (
 		"node-group-auto-discovery",
 		"One or more definition(s) of node group auto-discovery. "+
 			"A definition is expressed `<name of discoverer>:[<key>[=<value>]]`. "+
-			"The `aws` and `gce` cloud providers are currently supported. AWS matches by ASG tags, e.g. `asg:tag=tagKey,anotherTagKey`. "+
+			"The `aws`, `gce`, and `azure` cloud providers are currently supported. AWS matches by ASG tags, e.g. `asg:tag=tagKey,anotherTagKey`. "+
 			"GCE matches by IG name prefix, and requires you to specify min and max nodes per IG, e.g. `mig:namePrefix=pfx,min=0,max=10` "+
+			"Azure matches by VMSS tags, similar to AWS. And you can optionally specify a default min and max size, e.g. `label:tag=tagKey,anotherTagKey=bar,min=0,max=600`. "+
 			"Can be used multiple times.")
 
 	estimatorFlag = flag.String("estimator", estimator.BinpackingEstimatorName,