fix: error when updating IPv6 Primary IP

The API returns a CIDR range in the `ip` field for ipv6 primary IPs. This
caused the `PrimaryIPClient.Update` call to fail, because the response
was parsed as a `net.IP`, but should have been parsed using `net.ParseNetwork`.

The required logic was already implemented in the `PrimaryIPFromSchema`
function, but not used for the update call.

With this commit, the struct `hcloud.PrimaryIPUpdateResult` is marked as
deprecated, because using it to parse the response causes the error.

This error was originally found in hcloud-cli, and caused following error
message:

    ➜  ~ hcloud primary-ip update --auto-delete=false test-ip
    hcloud: updating Primary IP test-ip failed: invalid IP address: 2001:db8::/64

hcloud/primary_ip.go

@@ -92,6 +92,8 @@ type PrimaryIPUpdateOpts struct {
 
 // PrimaryIPUpdateResult defines the response
 // when updating a Primary IP.
+// This struct is deprecated because it does not work with IPv6.
+// Please use github.com/hetznercloud/hcloud-go/hcloud/schema.PrimaryIPUpdateResult instead.
 type PrimaryIPUpdateResult struct {
 	PrimaryIP PrimaryIP `json:"primary_ip"`
 }
@@ -311,12 +313,12 @@ func (c *PrimaryIPClient) Update(ctx context.Context, primaryIP *PrimaryIP, reqB
 		return nil, nil, err
 	}
 
-	respBody := PrimaryIPUpdateResult{}
+	var respBody schema.PrimaryIPUpdateResult
 	resp, err := c.client.Do(req, &respBody)
 	if err != nil {
 		return nil, resp, err
 	}
-	return &respBody.PrimaryIP, resp, nil
+	return PrimaryIPFromSchema(respBody.PrimaryIP), resp, nil
 }
 
 // Assign a Primary IP to a resource

hcloud/primary_ip_test.go

@@ -3,6 +3,7 @@ package hcloud
 import (
 	"context"
 	"encoding/json"
+	"net"
 	"net/http"
 	"testing"
 
@@ -333,8 +334,8 @@ func TestPrimaryIPClient(t *testing.T) {
 				t.Log(cmp.Diff(expectedReqBody, reqBody))
 				t.Error("unexpected request body")
 			}
-			json.NewEncoder(w).Encode(PrimaryIPUpdateResult{
-				PrimaryIP: PrimaryIP{ID: 1},
+			json.NewEncoder(w).Encode(schema.PrimaryIPUpdateResult{
+				PrimaryIP: schema.PrimaryIP{ID: 1, IP: "2001:db8::/64"},
 			})
 		})
 
@@ -347,11 +348,14 @@ func TestPrimaryIPClient(t *testing.T) {
 			Labels:     &labels,
 		}
 
-		primaryIP := PrimaryIP{ID: 1}
+		primaryIP := PrimaryIP{ID: 1, IP: net.ParseIP("2001:db8::")}
 		result, resp, err := env.Client.PrimaryIP.Update(ctx, &primaryIP, opts)
 		assert.NoError(t, err)
 		assert.NotNil(t, resp, "no response returned")
-		assert.Equal(t, *result, primaryIP, "no primary IP returned")
+		if result.ID != 1 {
+			t.Errorf("unexpected Primary IP ID: %v", result.ID)
+		}
+		assert.Equal(t, primaryIP.IP, result.IP, "parsed the wrong IP")
 	})
 	t.Run("Assign", func(t *testing.T) {
 		env := newTestEnv()

hcloud/schema/primary_ip.go

@@ -47,3 +47,9 @@ type PrimaryIPGetResult struct {
 type PrimaryIPListResult struct {
 	PrimaryIPs []PrimaryIP `json:"primary_ips"`
 }
+
+// PrimaryIPUpdateResult defines the response
+// when updating a Primary IP.
+type PrimaryIPUpdateResult struct {
+	PrimaryIP PrimaryIP `json:"primary_ip"`
+}