func changeUnits(a provision.App, units int, processName string, w io.Writer) error {
if a.GetDeploys() == 0 {
return errors.New("units can only be modified after the first deploy")
}
if units == 0 {
return errors.New("cannot change 0 units")
}
client, err := chooseDBSwarmNode()
if err != nil {
return err
}
imageId, err := image.AppCurrentImageName(a.GetName())
if err != nil {
return err
}
if processName == "" {
_, processName, err = dockercommon.ProcessCmdForImage(processName, imageId)
if err != nil {
return errors.WithStack(err)
}
}
return deployProcesses(client, a, imageId, processSpec{processName: processState{increment: units}})
}
func (p *dockerProvisioner) RemoveUnits(a provision.App, units uint, processName string, w io.Writer) error {
if a == nil {
return errors.New("remove units: app should not be nil")
}
if units == 0 {
return errors.New("cannot remove zero units")
}
var err error
if w == nil {
w = ioutil.Discard
}
imgId, err := image.AppCurrentImageName(a.GetName())
if err != nil {
return err
}
_, processName, err = dockercommon.ProcessCmdForImage(processName, imgId)
if err != nil {
return err
}
containers, err := p.listContainersByProcess(a.GetName(), processName)
if err != nil {
return err
}
if len(containers) < int(units) {
return errors.Errorf("cannot remove %d units from process %q, only %d available", units, processName, len(containers))
}
fmt.Fprintf(w, "\n---- Removing %d %s ----\n", units, pluralize("unit", int(units)))
p, err = p.cloneProvisioner(nil)
if err != nil {
return err
}
toRemove := make([]container.Container, 0, units)
for i := 0; i < int(units); i++ {
var (
containerID string
cont *container.Container
)
containerID, err = p.scheduler.GetRemovableContainer(a.GetName(), processName)
if err != nil {
return err
}
cont, err = p.GetContainer(containerID)
if err != nil {
return err
}
p.scheduler.ignoredContainers = append(p.scheduler.ignoredContainers, cont.ID)
toRemove = append(toRemove, *cont)
}
args := changeUnitsPipelineArgs{
app: a,
toRemove: toRemove,
writer: w,
provisioner: p,
}
pipeline := action.NewPipeline(
&removeOldRoutes,
&provisionRemoveOldUnits,
&provisionUnbindOldUnits,
)
err = pipeline.Execute(args)
if err != nil {
return errors.Wrap(err, "error removing routes, units weren't removed")
}
return nil
}
func addContainersWithHost(args *changeUnitsPipelineArgs) ([]container.Container, error) {
a := args.app
w := args.writer
var units int
processMsg := make([]string, 0, len(args.toAdd))
imageId := args.imageId
for processName, v := range args.toAdd {
units += v.Quantity
if processName == "" {
_, processName, _ = dockercommon.ProcessCmdForImage(processName, imageId)
}
processMsg = append(processMsg, fmt.Sprintf("[%s: %d]", processName, v.Quantity))
}
var destinationHost []string
if args.toHost != "" {
destinationHost = []string{args.toHost}
}
if w == nil {
w = ioutil.Discard
}
fmt.Fprintf(w, "\n---- Starting %d new %s %s ----\n", units, pluralize("unit", units), strings.Join(processMsg, " "))
oldContainers := make([]container.Container, 0, units)
for processName, cont := range args.toAdd {
for i := 0; i < cont.Quantity; i++ {
oldContainers = append(oldContainers, container.Container{
ProcessName: processName,
Status: cont.Status.String(),
})
}
}
rollbackCallback := func(c *container.Container) {
log.Errorf("Removing container %q due failed add units.", c.ID)
errRem := c.Remove(args.provisioner)
if errRem != nil {
log.Errorf("Unable to destroy container %q: %s", c.ID, errRem)
}
}
var (
createdContainers []*container.Container
m sync.Mutex
)
err := runInContainers(oldContainers, func(c *container.Container, toRollback chan *container.Container) error {
c, startErr := args.provisioner.start(c, a, imageId, w, args.exposedPort, destinationHost...)
if startErr != nil {
return startErr
}
toRollback <- c
m.Lock()
createdContainers = append(createdContainers, c)
m.Unlock()
fmt.Fprintf(w, " ---> Started unit %s [%s]\n", c.ShortID(), c.ProcessName)
return nil
}, rollbackCallback, true)
if err != nil {
return nil, err
}
result := make([]container.Container, len(createdContainers))
i := 0
for _, c := range createdContainers {
result[i] = *c
i++
}
return result, nil
}