feat: rolling deploy strategy for global service, always recreate

internal/cli/client/strategy.go

@@ -0,0 +1,177 @@
+package client
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"uncloud/internal/api"
+	"uncloud/internal/machine/api/pb"
+	"uncloud/internal/secret"
+)
+
+// Strategy defines how a service should be deployed or updated. Different implementations can provide various
+// deployment patterns such as rolling updates, blue/green deployments, etc.
+type Strategy interface {
+	// Plan returns the operation to reconcile the service to the desired state.
+	// If the service does not exist (new deployment), svc will be nil.
+	Plan(ctx context.Context, cli *Client, svc *api.Service, spec api.ServiceSpec) (Operation, error)
+}
+
+// RollingStrategy implements a rolling update deployment pattern where containers are updated one at a time
+// to minimize service disruption.
+type RollingStrategy struct{}
+
+func (s *RollingStrategy) Plan(
+	ctx context.Context, cli *Client, svc *api.Service, spec api.ServiceSpec,
+) (Operation, error) {
+	switch spec.Mode {
+	case "", api.ServiceModeReplicated:
+		return s.planReplicated(ctx, cli, svc, spec)
+	case api.ServiceModeGlobal:
+		return s.planGlobal(ctx, cli, svc, spec)
+	default:
+		return nil, fmt.Errorf("unsupported service mode: %s", spec.Mode)
+	}
+}
+
+// planReplicated creates a plan for a replicated service deployment.
+func (s *RollingStrategy) planReplicated(
+	ctx context.Context, cli *Client, svc *api.Service, spec api.ServiceSpec,
+) (Operation, error) {
+	return nil, errors.New("not implemented")
+}
+
+// planGlobal creates a plan for a global service deployment, ensuring one container runs on each available machine.
+// For machines with an existing container, it attempts to start a new container before removing the old one if
+// possible. If the new container would have port conflicts with the existing one, the old container is removed first.
+// It handles multiple containers per machine (though this should not occur in normal operation) and skips machines
+// that are down.
+func (s *RollingStrategy) planGlobal(
+	ctx context.Context, cli *Client, svc *api.Service, spec api.ServiceSpec,
+) (Operation, error) {
+	serviceID := ""
+	// Map machineID to service containers on that machine. For the global mode, there should be at most one
+	// container per machine but we use a slice to handle multiple containers that may exist due to a bug
+	// or interruption in the previous deployment.
+	containersOnMachine := make(map[string][]api.MachineContainer)
+	if svc != nil {
+		serviceID = svc.ID
+		for _, c := range svc.Containers {
+			containersOnMachine[c.MachineID] = append(containersOnMachine[c.MachineID], c)
+		}
+	} else {
+		// Generate a new service ID for the first service deployment.
+		var err error
+		serviceID, err = secret.NewID()
+		if err != nil {
+			return nil, fmt.Errorf("generate service ID: %w", err)
+		}
+	}
+
+	machines, err := cli.ListMachines(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("list machines: %w", err)
+	}
+
+	plan := &SequenceOperation{}
+	var machinesDown []*pb.MachineInfo
+	for _, m := range machines {
+		// Skip machines that are down but collect them to report a warning later.
+		if m.State == pb.MachineMember_DOWN {
+			machinesDown = append(machinesDown, m.Machine)
+			continue
+		}
+
+		containers := containersOnMachine[m.Machine.Id]
+		ops, err := reconcileGlobalContainer(containers, spec, serviceID, m.Machine.Id)
+		if err != nil {
+			return nil, err
+		}
+		plan.Operations = append(plan.Operations, ops...)
+	}
+
+	return plan, nil
+}
+
+func reconcileGlobalContainer(
+	containers []api.MachineContainer, spec api.ServiceSpec, serviceID, machineID string,
+) ([]Operation, error) {
+	var ops []Operation
+
+	if len(containers) == 0 {
+		// No containers on this machine, create a new one.
+		ops = append(ops, &RunContainerOperation{
+			ServiceID: serviceID,
+			Spec:      spec,
+			MachineID: machineID,
+		})
+		return ops, nil
+	}
+
+	// Check if there is a container with the same spec already running. If so, remove the rest.
+	upToDate := false
+	for i, c := range containers {
+		if c.Container.State != api.StateRunning && c.Container.State != api.StateRestarting {
+			// Skip containers that are not running.
+			continue
+		}
+
+		svcSpec := c.Container.ServiceSpec()
+		if svcSpec.Equals(spec) {
+			// The container is already running with the same spec.
+			upToDate = true
+			for j, old := range containers {
+				if i == j {
+					continue
+				}
+				ops = append(ops, &RemoveContainerOperation{
+					ServiceID:   serviceID,
+					ContainerID: old.Container.ID,
+					MachineID:   old.MachineID,
+				})
+			}
+			break
+		}
+	}
+	if upToDate {
+		return ops, nil
+	}
+
+	// The machine has containers but none of them match the new spec.
+	// Stop the old non-stopped containers that have conflicting ports with the new spec before running a new one.
+	for _, c := range containers {
+		if !c.Container.Stopped() {
+			conflictingPorts, err := c.Container.ConflictingServicePorts(spec.Ports)
+			if err != nil {
+				return nil, fmt.Errorf("check conflicting ports: %w", err)
+			}
+
+			if len(conflictingPorts) > 0 {
+				// Stop the running container with conflicting ports.
+				ops = append(ops, &StopContainerOperation{
+					ServiceID:   serviceID,
+					ContainerID: c.Container.ID,
+					MachineID:   c.MachineID,
+				})
+			}
+		}
+	}
+
+	// Run a new container.
+	ops = append(ops, &RunContainerOperation{
+		ServiceID: serviceID,
+		Spec:      spec,
+		MachineID: machineID,
+	})
+
+	// Remove the old containers.
+	for _, c := range containers {
+		ops = append(ops, &RemoveContainerOperation{
+			ServiceID:   serviceID,
+			ContainerID: c.Container.ID,
+			MachineID:   c.MachineID,
+		})
+	}
+
+	return ops, nil
+}