Adding A New Backend

Create new backend

To add a new backend, create a new folder in backend/ with the name of the backend. The package name should be a new package name related to the new storage type.

If you embed the backend.BackendUnsupported type with the new storage struct, then any interface functions that are not implemented will automatically return the s3err.ErrNotImplemented error. For example:

package mystorage

type MyStorage struct {
	backend.BackendUnsupported
}

Implement the Stringer interface for the the new type:

func (m *MyStorage) String() string { return "My Storage" }

It is also recommended to implement the Shutdown method that will be called upon gateway termination, but this is optional and the backend.BackendUnsupported provides a no-op shutdown:

func (m *MyStorage) Shutdown() {
	// do important cleanup things here
}

Implement the backend.Backend methods based on desired API functionality.
Implementing the backend.Backend methods will translate how you want your storage service to handle the corresponding frontend requests.

Add backend to versitygw app

Create a new file: cmd/versitygw/mystorage.go with the appropriate name for the new backend type.

Create a new function that takes no args and returns a *cli.Command, and fill out appropriate fields for the new backend:

func mystorageCommand() *cli.Command {
	return &cli.Command{
		Name:  "mystorage",
		Usage: "usage for mystorage",
		Description: "description for mystorage",
		Action: runMyStorage,
	}
}

And create the action function to run with the signature func (ctx *cli.Context) error:

func runMyStorage(ctx *cli.Context) error {
	// do any setup or option parsing here

	be, err := mystorage.New()
	if err != nil {
		return fmt.Errorf("init mystorage: %w", err)
	}

	return runGateway(ctx.Context, be)
}

Add the storage subcommand to the main app in main() in cmd/versitygw/main.go:

	app.Commands = []*cli.Command{
		posixCommand(),
		scoutfsCommand(),
		s3Command(),
		azureCommand(),
		mystorageCommand(),
		adminCommand(),
		testCommand(),
	}

Include documentation for the wiki if this will be added with a pull request.