DockerCLI/internal/pkg/containerized/pauseandrun.go

75 lines
2.0 KiB
Go

package containerized
import (
"context"
"github.com/containerd/containerd"
"github.com/containerd/containerd/errdefs"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
)
// AtomicImageUpdate will perform an update of the given container with the new image
// and verify success via the provided healthcheckFn. If the healthcheck fails, the
// container will be reverted to the prior image
func AtomicImageUpdate(ctx context.Context, container containerd.Container, image containerd.Image, healthcheckFn func() error) error {
updateCompleted := false
err := pauseAndRun(ctx, container, func() error {
if err := container.Update(ctx, WithUpgrade(image)); err != nil {
return errors.Wrap(err, "failed to update to new image")
}
updateCompleted = true
task, err := container.Task(ctx, nil)
if err != nil {
if errdefs.IsNotFound(err) {
return nil
}
return errors.Wrap(err, "failed to lookup task")
}
return task.Kill(ctx, sigTERM)
})
if err != nil {
if updateCompleted {
logrus.WithError(err).Error("failed to update, rolling back")
return rollBack(ctx, container)
}
return err
}
if err := healthcheckFn(); err != nil {
logrus.WithError(err).Error("failed health check, rolling back")
return rollBack(ctx, container)
}
return nil
}
func rollBack(ctx context.Context, container containerd.Container) error {
return pauseAndRun(ctx, container, func() error {
if err := container.Update(ctx, WithRollback); err != nil {
return err
}
task, err := container.Task(ctx, nil)
if err != nil {
if errdefs.IsNotFound(err) {
return nil
}
return errors.Wrap(err, "failed to lookup task")
}
return task.Kill(ctx, sigTERM)
})
}
func pauseAndRun(ctx context.Context, container containerd.Container, fn func() error) error {
task, err := container.Task(ctx, nil)
if err != nil {
if errdefs.IsNotFound(err) {
return fn()
}
return errors.Wrap(err, "failed to lookup task")
}
if err := task.Pause(ctx); err != nil {
return errors.Wrap(err, "failed to pause task")
}
defer task.Resume(ctx)
return fn()
}