expand CAPI_GROUP usage to cover node group size annotations

This change updates the logic for the clusterapi autoscaler provider so
that the `CAPI_GROUP` environment variable will also affect the
annotations keys for minimum and maximum node group size. It also addes
unit tests and an update to the readme.

cluster-autoscaler/cloudprovider/clusterapi/README.md

@@ -121,6 +121,10 @@ some situations, such as testing or prototyping, you may wish to change this
 group variable. For these situations you may use the environment variable
 `CAPI_GROUP` to change the group that the provider will use.
 
+Please note that setting the `CAPI_GROUP` environment variable will also cause the
+annotations for minimum and maximum size to change. For example, if `CAPI_GROUP=test.k8s.io`
+then the minimum size annotation key will be `test.k8s.io/cluster-api-autoscaler-node-group-min-size`.
+
 ## Sample manifest
 
 A sample manifest that will create a deployment running the autoscaler is

cluster-autoscaler/cloudprovider/clusterapi/clusterapi_utils.go

@@ -17,6 +17,7 @@ limitations under the License.
 package clusterapi
 
 import (
+	"fmt"
 	"strconv"
 	"strings"
 
@@ -28,8 +29,6 @@ import (
 const (
 	deprecatedNodeGroupMinSizeAnnotationKey = "cluster.k8s.io/cluster-api-autoscaler-node-group-min-size"
 	deprecatedNodeGroupMaxSizeAnnotationKey = "cluster.k8s.io/cluster-api-autoscaler-node-group-max-size"
-	nodeGroupMinSizeAnnotationKey           = "cluster.x-k8s.io/cluster-api-autoscaler-node-group-min-size"
-	nodeGroupMaxSizeAnnotationKey           = "cluster.x-k8s.io/cluster-api-autoscaler-node-group-max-size"
 	clusterNameLabel                        = "cluster.x-k8s.io/cluster-name"
 	deprecatedClusterNameLabel              = "cluster.k8s.io/cluster-name"
 )
@@ -52,6 +51,13 @@ var (
 	// errInvalidMaxAnnotationValue is the error returned when a
 	// machine set has a non-integral max annotation value.
 	errInvalidMaxAnnotation = errors.New("invalid max annotation")
+
+	// nodeGroupMinSizeAnnotationKey and nodeGroupMaxSizeAnnotationKey are the keys
+	// used in MachineSet and MachineDeployment annotations to specify the limits
+	// for the node group. Because the keys can be affected by the CAPI_GROUP env
+	// variable, they are initialized here.
+	nodeGroupMinSizeAnnotationKey = getNodeGroupMinSizeAnnotationKey()
+	nodeGroupMaxSizeAnnotationKey = getNodeGroupMaxSizeAnnotationKey()
 )
 
 type normalizedProviderID string
@@ -180,3 +186,19 @@ func clusterNameFromResource(r *unstructured.Unstructured) string {
 
 	return ""
 }
+
+// getNodeGroupMinSizeAnnotationKey returns the key that is used for the
+// node group minimum size annotation. This is needed because the user can
+// change the defaulte group name by using the CAPI_GROUP environment variable.
+func getNodeGroupMinSizeAnnotationKey() string {
+	key := fmt.Sprintf("%s/cluster-api-autoscaler-node-group-min-size", getCAPIGroup())
+	return key
+}
+
+// getNodeGroupMaxSizeAnnotationKey returns the key that is used for the
+// node group maximum size annotation. This is needed because the user can
+// change the defaulte group name by using the CAPI_GROUP environment variable.
+func getNodeGroupMaxSizeAnnotationKey() string {
+	key := fmt.Sprintf("%s/cluster-api-autoscaler-node-group-max-size", getCAPIGroup())
+	return key
+}

cluster-autoscaler/cloudprovider/clusterapi/clusterapi_utils_test.go

@@ -17,6 +17,8 @@ limitations under the License.
 package clusterapi
 
 import (
+	"fmt"
+	"os"
 	"reflect"
 	"strings"
 	"testing"
@@ -689,4 +691,23 @@ func Test_clusterNameFromResource(t *testing.T) {
 			}
 		})
 	}
+
+}
+func Test_getNodeGroupSizeAnnotationKey(t *testing.T) {
+	testgroup := "test.k8s.io"
+	if err := os.Setenv(CAPIGroupEnvVar, testgroup); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	expected := fmt.Sprintf("%s/cluster-api-autoscaler-node-group-min-size", testgroup)
+	observed := getNodeGroupMinSizeAnnotationKey()
+	if expected != observed {
+		t.Errorf("min size annotations keys do not match: observed=%s, expected=%s", observed, expected)
+	}
+
+	expected = fmt.Sprintf("%s/cluster-api-autoscaler-node-group-max-size", testgroup)
+	observed = getNodeGroupMaxSizeAnnotationKey()
+	if expected != observed {
+		t.Errorf("max size annotations keys do not match: observed=%s, expected=%s", observed, expected)
+	}
 }