fix enumeration of more than 1000 Nova hypervisors

Pagination was introduced in microversion 2.33, so our microversion upgrade
in 2fbae7d (PR #579) broke this
accidentally. This was not caught in QA because the QA regions are not
big enough to reach a 4-digit hypervisor count.

internal/plugins/nova/gophercloud_fixes.go

@@ -0,0 +1,74 @@
+/*******************************************************************************
+*
+* Copyright 2024 SAP SE
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You should have received a copy of the License along with this
+* program. If not, 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 nova
+
+import (
+	"net/http"
+
+	"github.com/gophercloud/gophercloud/v2"
+	"github.com/gophercloud/gophercloud/v2/openstack/compute/v2/hypervisors"
+	"github.com/gophercloud/gophercloud/v2/pagination"
+)
+
+// Like hypervisors.HypervisorPage, but fixes bug <https://github.com/gophercloud/gophercloud/issues/3222> by being a LinkedPageBase instead of a SinglePageBase.
+type hypervisorPage struct {
+	pagination.LinkedPageBase
+}
+
+// IsEmpty is required for LinkedPageBase to work.
+func (page hypervisorPage) IsEmpty() (bool, error) {
+	if page.StatusCode == http.StatusNoContent {
+		return true, nil
+	}
+
+	var data struct {
+		Hypervisors []struct{} `json:"hypervisors"`
+	}
+	err := page.ExtractInto(&data)
+	return len(data.Hypervisors) == 0, err
+}
+
+// NextPageURL is required for LinkedPageBase to work.
+func (page hypervisorPage) NextPageURL() (string, error) {
+	var s struct {
+		Links []gophercloud.Link `json:"hypervisors_links"`
+	}
+	err := page.ExtractInto(&s)
+	if err != nil {
+		return "", err
+	}
+	return gophercloud.ExtractNextURL(s.Links)
+}
+
+// Like hypervisors.List(), but fixes bug <https://github.com/gophercloud/gophercloud/issues/3222>.
+func hypervisorsList(client *gophercloud.ServiceClient, opts hypervisors.ListOptsBuilder) pagination.Pager {
+	url := client.ServiceURL("os-hypervisors", "detail")
+	if opts != nil {
+		query, err := opts.ToHypervisorListQuery()
+		if err != nil {
+			return pagination.Pager{Err: err}
+		}
+		url += query
+	}
+
+	return pagination.NewPager(client, url, func(r pagination.PageResult) pagination.Page {
+		return hypervisorPage{pagination.LinkedPageBase{PageResult: r}}
+	})
+}

internal/plugins/nova/hypervisor_selection.go

@@ -55,14 +55,14 @@ type HypervisorSelection struct {
 // HypervisorSelection, and calls the given callback once for each of them.
 func (s HypervisorSelection) ForeachHypervisor(ctx context.Context, novaV2, placementV1 *gophercloud.ServiceClient, action func(MatchingHypervisor) error) error {
 	// enumerate hypervisors
-	page, err := hypervisors.List(novaV2, nil).AllPages(ctx)
+	page, err := hypervisorsList(novaV2, nil).AllPages(ctx)
 	if err != nil {
 		return fmt.Errorf("while listing hypervisors: %w", err)
 	}
 	var hypervisorData struct {
 		Hypervisors []Hypervisor `json:"hypervisors"`
 	}
-	err = page.(hypervisors.HypervisorPage).ExtractInto(&hypervisorData)
+	err = page.(hypervisorPage).ExtractInto(&hypervisorData)
 	if err != nil {
 		return fmt.Errorf("while listing hypervisors: %w", err)
 	}