// projectHasInstance checks for all the possible zones if there's already an instance for the project.
// It returns the name of the zone at the first instance it finds, if any.
func (d *Deployer) projectHasInstance() (zone string, err error) {
s, err := compute.New(d.Client)
if err != nil {
return "", err
}
// TODO(mpl): make use of the handler's cached zones.
zl, err := compute.NewZonesService(s).List(d.Conf.Project).Do()
if err != nil {
return "", fmt.Errorf("could not get a list of zones: %v", err)
}
computeService, _ := compute.New(d.Client)
var zoneOnce sync.Once
var grp syncutil.Group
errc := make(chan error, 1)
zonec := make(chan string, 1)
timeout := time.NewTimer(30 * time.Second)
defer timeout.Stop()
for _, z := range zl.Items {
z := z
grp.Go(func() error {
list, err := computeService.Instances.List(d.Conf.Project, z.Name).Do()
if err != nil {
return fmt.Errorf("could not list existing instances: %v", err)
}
if len(list.Items) > 0 {
zoneOnce.Do(func() {
zonec <- z.Name
})
}
return nil
})
}
go func() {
errc <- grp.Err()
}()
// We block until either an instance was found in a zone, or all the instance
// listing is done. Or we timed-out.
select {
case err = <-errc:
return "", err
case zone = <-zonec:
// We voluntarily ignore any listing error if we found at least one instance
// because that's what we primarily want to report about.
return zone, nil
case <-timeout.C:
return "", errors.New("timed out")
}
}
// TODO(bradfitz,mpl): move this to go4.org/cloud/google/gceutil
func ZonesOfRegion(hc *http.Client, project, region string) (zones []string, err error) {
s, err := compute.New(hc)
if err != nil {
return nil, err
}
zl, err := compute.NewZonesService(s).List(project).Do()
if err != nil {
return nil, fmt.Errorf("could not get a list of zones: %v", err)
}
if zl.NextPageToken != "" {
return nil, errors.New("TODO: more than one page of zones found; use NextPageToken")
}
for _, z := range zl.Items {
if path.Base(z.Region) != region {
continue
}
zones = append(zones, z.Name)
}
return zones, nil
}