feat: allow to filter machines for global service deployments

internal/cli/client/caddy.go

@@ -22,7 +22,7 @@ var caddyImageTagRegex = regexp.MustCompile(`^2\.\d+\.\d+$`)
 // NewCaddyDeployment creates a new deployment for a Caddy reverse proxy service.
 // The service is deployed in global mode to all machines in the cluster. If the image is not provided, the latest
 // version of the official Caddy Docker image is used.
-func (cli *Client) NewCaddyDeployment(image string) (*Deployment, error) {
+func (cli *Client) NewCaddyDeployment(image string, filter MachineFilter) (*Deployment, error) {
 	latest, err := latestCaddyImage()
 	if err != nil {
 		return nil, fmt.Errorf("look up latest Caddy image: %w", err)
@@ -56,7 +56,7 @@ func (cli *Client) NewCaddyDeployment(image string) (*Deployment, error) {
 		},
 	}
 
-	return cli.NewDeployment(spec, &RollingStrategy{})
+	return cli.NewDeployment(spec, &RollingStrategy{MachineFilter: filter})
 }
 
 // latestCaddyImage returns the latest image of the official Caddy Docker image on Docker Hub.

internal/cli/client/caddy_test.go

@@ -15,7 +15,7 @@ func TestClient_NewCaddyDeployment(t *testing.T) {
 	t.Run("latest image from Docker Hub", func(t *testing.T) {
 		t.Parallel()
 
-		deploy, err := cli.NewCaddyDeployment("")
+		deploy, err := cli.NewCaddyDeployment("", nil)
 		require.NoError(t, err)
 
 		assert.Equal(t, "caddy", deploy.Spec.Name)
@@ -42,7 +42,7 @@ func TestClient_NewCaddyDeployment(t *testing.T) {
 		t.Parallel()
 
 		image := "my-caddy:1.2.3"
-		deploy, err := cli.NewCaddyDeployment(image)
+		deploy, err := cli.NewCaddyDeployment(image, nil)
 		require.NoError(t, err)
 
 		assert.Equal(t, "caddy", deploy.Spec.Name)

internal/cli/client/deploy.go

@@ -7,6 +7,7 @@ import (
 	"github.com/distribution/reference"
 	"strings"
 	"uncloud/internal/api"
+	"uncloud/internal/machine/api/pb"
 	"uncloud/internal/secret"
 )
 
@@ -25,6 +26,10 @@ type Plan struct {
 	SequenceOperation
 }
 
+// MachineFilter determines which machines participate in a deployment operation by returning true for
+// machines that should be included.
+type MachineFilter func(m *pb.MachineInfo) bool
+
 // NewDeployment creates a new deployment for the given service specification.
 // If strategy is nil, a default RollingStrategy will be used.
 func (cli *Client) NewDeployment(spec api.ServiceSpec, strategy Strategy) (*Deployment, error) {

internal/cli/client/strategy.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"slices"
 	"uncloud/internal/api"
 	"uncloud/internal/machine/api/pb"
 	"uncloud/internal/secret"
@@ -19,7 +20,10 @@ type Strategy interface {
 
 // RollingStrategy implements a rolling update deployment pattern where containers are updated one at a time
 // to minimize service disruption.
-type RollingStrategy struct{}
+type RollingStrategy struct {
+	// MachineFilter optionally restricts which machines participate in this deployment.
+	MachineFilter MachineFilter
+}
 
 func (s *RollingStrategy) Plan(
 	ctx context.Context, cli *Client, svc *api.Service, spec api.ServiceSpec,
@@ -72,6 +76,12 @@ func (s *RollingStrategy) planGlobal(
 	if err != nil {
 		return plan, fmt.Errorf("list machines: %w", err)
 	}
+	// Filter machines if a machine filter is provided.
+	if s.MachineFilter != nil {
+		machines = slices.DeleteFunc(machines, func(m *pb.MachineMember) bool {
+			return !s.MachineFilter(m.Machine)
+		})
+	}
 
 	// TODO: figure out how to return a warning if there are machines down. Embed the machinesDown in the plan?
 	//  WARNING: failed to run a service container on machine '%s' which is Down.