chore: init scheduler entities

pkg/client/deploy/scheduler/service.go

@@ -0,0 +1,51 @@
+package scheduler
+
+import (
+	"errors"
+
+	"github.com/psviderski/uncloud/internal/machine/api/pb"
+	"github.com/psviderski/uncloud/pkg/api"
+)
+
+type ServiceScheduler struct {
+	machines    []*Machine
+	spec        api.ServiceSpec
+	constraints []Constraint
+}
+
+func NewServiceScheduler(machines []*Machine, spec api.ServiceSpec, constraints []Constraint) *ServiceScheduler {
+	specConstraints := constraintsFromSpec(spec)
+	specConstraints = append(specConstraints, constraints...)
+
+	return &ServiceScheduler{
+		machines:    machines,
+		spec:        spec,
+		constraints: specConstraints,
+	}
+}
+
+func (s *ServiceScheduler) AvailableMachines() ([]*Machine, error) {
+	var available []*Machine
+	for _, machine := range s.machines {
+		if s.evaluateConstraints(machine) {
+			available = append(available, machine)
+		}
+	}
+	if len(available) == 0 {
+		return nil, errors.New("no machines available that satisfy all constraints")
+	}
+	return available, nil
+}
+
+func (s *ServiceScheduler) evaluateConstraints(machine *Machine) bool {
+	for _, c := range s.constraints {
+		if !c.Evaluate(machine) {
+			return false
+		}
+	}
+	return true
+}
+
+func (s *ServiceScheduler) ScheduleContainer() ([]*pb.MachineInfo, error) {
+	return nil, errors.New("not implemented")
+}