Redesign create.rs

[utam0k]

The create.rs should be split up more, but I don't have a good idea how to split it up, so if you have any suggestions, please let me know.

Ideas

• builder pattern(remove unnecessary clone() in create.rs #117 (comment))
  https://doc.rust-lang.org/1.0.0/style/ownership/builders.html

[nimrodshn]

builder pattern

Sounds good 👍

[Furisto]

This is what the preliminary api looks like:

 // required values (must be specified in new...)
        // - create
        //   - id
        //   - bundle
        // - exec
        //   - id
        //
        // use with_... methods to specify
        // optional values
        // - console-socket
        // - pid-file
        //
        // overwritable values
        // - systemd (default true)
        // - root_path (default /run/youki)
        //
        // overwritable values (for exec only?)
        // - env
        // - cwd
        // - container command
        //
        // calculated in build()
        // computed values
        // - rootless
        // - container_dir
        // - spec
        // - notify_socket
        // - container 

        // create
        let container = ContainerBuilder::new_init(id, bundle)?
        .with_pid_file(pid_file) // optional
        .with_console_socket(console_socket) //optional
        .with_systemd(false) // overwrite default
        .with_root_path(root_path) // overwrite default
        .build()?;

        // exec
        let container = ContainerBuilder::new_tenant(id)
        .with_pid_file(pid_file)
        .with_console_socket(console_socket)
        .with_cwd(cwd)
        .with_env(env)
        .with_container_command(vec!["sleep".to_owned(), "9001".to_owned()])
        .build()?;