open-nomad/scheduler/scheduler_test.go

115 lines
2.6 KiB
Go

package scheduler
import (
"log"
"os"
"sync"
"testing"
"github.com/hashicorp/nomad/nomad/state"
"github.com/hashicorp/nomad/nomad/structs"
)
// Harness is a lightweight testing harness for schedulers.
// It manages a state store copy and provides the planner
// interface. It can be extended for various testing uses.
type Harness struct {
State *state.StateStore
Planner Planner
planLock sync.Mutex
Plans []*structs.Plan
nextIndex uint64
nextIndexLock sync.Mutex
}
// NewHarness is used to make a new testing harness
func NewHarness(t *testing.T) *Harness {
state, err := state.NewStateStore(os.Stderr)
if err != nil {
t.Fatalf("err: %v", err)
}
h := &Harness{
State: state,
nextIndex: 1,
}
return h
}
// SubmitPlan is used to handle plan submission
func (h *Harness) SubmitPlan(plan *structs.Plan) (*structs.PlanResult, State, error) {
// Ensure sequential plan application
h.planLock.Lock()
defer h.planLock.Unlock()
// Store the plan
h.Plans = append(h.Plans, plan)
// Check for custom planner
if h.Planner != nil {
return h.Planner.SubmitPlan(plan)
}
// Get the index
index := h.NextIndex()
// Prepare the result
result := new(structs.PlanResult)
result.NodeEvict = plan.NodeEvict
result.NodeAllocation = plan.NodeAllocation
result.AllocIndex = index
// Flatten evicts and allocs
var evicts []string
var allocs []*structs.Allocation
for _, evictList := range plan.NodeEvict {
evicts = append(evicts, evictList...)
}
for _, allocList := range plan.NodeAllocation {
allocs = append(allocs, allocList...)
}
// Apply the full plan
err := h.State.UpdateAllocations(index, evicts, allocs)
return result, nil, err
}
// NextIndex returns the next index
func (h *Harness) NextIndex() uint64 {
h.nextIndexLock.Lock()
defer h.nextIndexLock.Unlock()
idx := h.nextIndex
h.nextIndex += 1
return idx
}
// Snapshot is used to snapshot the current state
func (h *Harness) Snapshot() State {
snap, _ := h.State.Snapshot()
return snap
}
// Scheduler is used to return a new scheduler from
// a snapshot of current state using the harness for planning.
func (h *Harness) Scheduler(factory Factory) Scheduler {
logger := log.New(os.Stderr, "", log.LstdFlags)
return factory(logger, h.Snapshot(), h)
}
// Process is used to process an evaluation given a factory
// function to create the scheduler
func (h *Harness) Process(factory Factory, eval *structs.Evaluation) error {
sched := h.Scheduler(factory)
return sched.Process(eval)
}
// noErr is used to assert there are no errors
func noErr(t *testing.T, err error) {
if err != nil {
t.Fatalf("err: %v", err)
}
}