package command import ( "bytes" "context" "fmt" "path/filepath" "sync" "testing" "golang.org/x/sync/errgroup" "github.com/hashicorp/packer/packer" ) // NewParallelTestBuilder will return a New ParallelTestBuilder that will // unlock after `runs` builds func NewParallelTestBuilder(runs int) *ParallelTestBuilder { pb := &ParallelTestBuilder{} pb.wg.Add(runs) return pb } // The ParallelTestBuilder's first run will lock type ParallelTestBuilder struct { wg sync.WaitGroup } func (b *ParallelTestBuilder) Prepare(raws ...interface{}) ([]string, error) { return nil, nil } func (b *ParallelTestBuilder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (packer.Artifact, error) { ui.Say("building") b.wg.Done() return nil, nil } // LockedBuilder wont run until unlock is called type LockedBuilder struct{ unlock chan interface{} } func (b *LockedBuilder) Prepare(raws ...interface{}) ([]string, error) { return nil, nil } func (b *LockedBuilder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (packer.Artifact, error) { ui.Say("locking build") select { case <-b.unlock: case <-ctx.Done(): return nil, ctx.Err() } return nil, nil } // testMetaFile creates a Meta object that includes a file builder func testMetaParallel(t *testing.T, builder *ParallelTestBuilder, locked *LockedBuilder) Meta { var out, err bytes.Buffer return Meta{ CoreConfig: &packer.CoreConfig{ Components: packer.ComponentFinder{ Builder: func(n string) (packer.Builder, error) { switch n { case "parallel-test": return builder, nil case "lock": return locked, nil default: panic(n) } }, }, }, Ui: &packer.BasicUi{ Writer: &out, ErrorWriter: &err, }, } } func TestBuildParallel_1(t *testing.T) { // testfile that running 6 builds, with first one locks 'forever', other // builds should go through. b := NewParallelTestBuilder(5) locked := &LockedBuilder{unlock: make(chan interface{})} c := &BuildCommand{ Meta: testMetaParallel(t, b, locked), } args := []string{ fmt.Sprintf("-parallel=true"), filepath.Join(testFixture("parallel"), "template.json"), } wg := errgroup.Group{} wg.Go(func() error { if code := c.Run(args); code != 0 { fatalCommand(t, c.Meta) } return nil }) b.wg.Wait() // ran 5 times close(locked.unlock) // unlock locking one wg.Wait() // wait for termination }