fix: wait server firewall actions to settle (#209)

Closes #205

Prevents a server `locked` error from the API, when trying to change the
type of the server, while `firewall_apply` are still running in the
backend.

The `firewall_apply` actions are triggered by label selectors.

builder/hcloud/step_create_server.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"net/netip"
 	"os"
+	"slices"
 	"sort"
 	"strings"
 
@@ -142,6 +143,16 @@ func (s *stepCreateServer) Run(ctx context.Context, state multistep.StateBag) mu
 	}
 	state.Put(StateServerIP, serverIP)
 
+	// Wait that the server to settle before continuing. Prevents possible `locked`
+	// error when changing the server type.
+	actions, err := getServerRunningActions(ctx, client, server)
+	if err != nil {
+		return errorHandler(state, ui, "Could not fetch server running actions", err)
+	}
+	if err := client.Action.WaitFor(ctx, actions...); err != nil {
+		return errorHandler(state, ui, "Could not wait for server running actions", err)
+	}
+
 	if c.UpgradeServerType != "" {
 		ui.Say("Upgrading server type...")
 		serverChangeTypeAction, _, err := client.Server.ChangeType(ctx, server, hcloud.ServerChangeTypeOpts{
@@ -302,3 +313,24 @@ func firstAvailableIP(server *hcloud.Server) string {
 	}
 	return ""
 }
+
+func getServerRunningActions(ctx context.Context, client *hcloud.Client, server *hcloud.Server) ([]*hcloud.Action, error) {
+	actions, err := client.Firewall.Action.All(ctx,
+		hcloud.ActionListOpts{
+			Status: []hcloud.ActionStatus{
+				hcloud.ActionStatusRunning,
+			},
+		},
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	actions = slices.DeleteFunc(actions, func(action *hcloud.Action) bool {
+		return !slices.ContainsFunc(action.Resources, func(resource *hcloud.ActionResource) bool {
+			return resource.Type == hcloud.ActionResourceTypeServer && resource.ID == server.ID
+		})
+	})
+
+	return actions, nil
+}

builder/hcloud/step_create_server_test.go

@@ -63,6 +63,13 @@ func TestStepCreateServer(t *testing.T) {
 						"meta": { "pagination": { "page": 1 }}
 					}`,
 				},
+				{Method: "GET", Path: "/firewalls/actions?page=1&status=running",
+					Status: 200,
+					JSONRaw: `{
+						"actions": [],
+						"meta": { "pagination": { "page": 1 }}
+					}`,
+				},
 			},
 			WantStepAction: multistep.ActionContinue,
 			WantStateFunc: func(t *testing.T, state multistep.StateBag) {
@@ -126,6 +133,13 @@ func TestStepCreateServer(t *testing.T) {
 						"meta": { "pagination": { "page": 1 }}
 					}`,
 				},
+				{Method: "GET", Path: "/firewalls/actions?page=1&status=running",
+					Status: 200,
+					JSONRaw: `{
+						"actions": [],
+						"meta": { "pagination": { "page": 1 }}
+					}`,
+				},
 			},
 
 			WantStepAction: multistep.ActionContinue,
@@ -220,6 +234,13 @@ func TestStepCreateServer(t *testing.T) {
 						"meta": { "pagination": { "page": 1 }}
 					}`,
 				},
+				{Method: "GET", Path: "/firewalls/actions?page=1&status=running",
+					Status: 200,
+					JSONRaw: `{
+						"actions": [],
+						"meta": { "pagination": { "page": 1 }}
+					}`,
+				},
 			},
 			WantStepAction: multistep.ActionContinue,
 			WantStateFunc: func(t *testing.T, state multistep.StateBag) {
@@ -319,6 +340,13 @@ func TestStepCreateServer(t *testing.T) {
 						"meta": { "pagination": { "page": 1 }}
 					}`,
 				},
+				{Method: "GET", Path: "/firewalls/actions?page=1&status=running",
+					Status: 200,
+					JSONRaw: `{
+						"actions": [],
+						"meta": { "pagination": { "page": 1 }}
+					}`,
+				},
 			},
 			WantStepAction: multistep.ActionContinue,
 			WantStateFunc: func(t *testing.T, state multistep.StateBag) {