packer-cn/command/build_parallel_test.go

101 lines
2.1 KiB
Go

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 whose first run
// will lock until unlockOnce is closed and that will unlock after `runs`
// builds
func NewParallelTestBuilder(runs int) *ParallelTestBuilder {
pb := &ParallelTestBuilder{
unlockOnce: make(chan interface{}),
}
pb.wg.Add(runs)
return pb
}
// The ParallelTestBuilder's first run will lock
type ParallelTestBuilder struct {
once sync.Once
unlockOnce chan interface{}
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) {
b.once.Do(func() {
ui.Say("locking build")
<-b.unlockOnce
b.wg.Add(1) // avoid a panic
})
ui.Say("building")
b.wg.Done()
return nil, nil
}
// testMetaFile creates a Meta object that includes a file builder
func testMetaParallel(t *testing.T, builder *ParallelTestBuilder) 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
default:
panic(n)
}
},
},
},
Ui: &packer.BasicUi{
Writer: &out,
ErrorWriter: &err,
},
}
}
func TestBuildParallel(t *testing.T) {
// testfile that running 6 builds, with first one locks 'forever', other
// builds should go through.
b := NewParallelTestBuilder(5)
c := &BuildCommand{
Meta: testMetaParallel(t, b),
}
args := []string{
fmt.Sprintf("-parallel=2"),
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(b.unlockOnce) // unlock locking one
wg.Wait() // wait for termination
}