fix(backups-create): returns an error when the backup fails

[josephpage]

Context

backups-create waits for the backup to finish (it polls the backup status until it is done or error) and prints "Backup failed" on stderr when the backup ends in error, but it returns no error:

	if backup.Status == scalingo.BackupStatusDone {
		io.Status(color.New(color.FgGreen).Sprint("Backup successfully finished"))
	} else {
		io.Error(color.New(color.FgRed).Sprintf("Backup failed"))
	}
	return nil

So the command exits with the status 0 even when the backup failed. In a CI/CD pipeline (the typical use case of a manual backup: back up before deploying a new version), the next step is run anyway.

Other commands do fail

Returning an error when the asynchronous operation they wait for fails is what other commands do:

• deployments.Stream (used by deploy and deployment-follow) returns ErrDeploymentFailed:

				if !anyDeployment && scalingo.IsFinishedString(scalingo.DeploymentStatus(statusData.Content)) {
					if scalingo.HasFailedString(scalingo.DeploymentStatus(statusData.Content)) {
						return ErrDeploymentFailed
					}
					return nil
				}

• apps.OperationWaiter.WaitOperation (used by restart, scale and run) returns an error:

			case "error":
				fmt.Printf("\bOperation '%s' failed, an error occurred: %v\n", op.Type, op.Error)
				return op, errors.Newf(ctx, "operation %v failed", op.ID)

In both cases the cmd layer calls errorQuit(ctx, err), which exits with the code 1.

Changes

db.CreateBackup returns an error when the backup does not end in the done status, so backups-create now exits with the code 1. The failure is displayed by the standard error reporting (An error occurred: backup <id> failed) instead of the custom message.

• Add a changelog entry in the section "To Be Released" of CHANGELOG.md

Notes

• this is a behaviour change, and that is the point: a script relying on the previous behaviour (a failed backup not failing the command) now has to handle the error. Tell me if you would rather keep it for a major version.
• gofmt reports nothing on the modified file. I did not add a test: the repository tests pure helpers, and this path would need a mocked client (config.ScalingoClient is a package-level function). Happy to add one if you have a pattern in mind.

[EtienneM]

Thanks for your contribution