cubic 0.14.0

Cubic is a lightweight command line manager for virtual machines. It has a simple, daemon-less and rootless design. All Cubic virtual machines run isolated in the user context. Cubic is built on top of QEMU, KVM and cloud-init. Show all supported images: $ cubic images Create a new virtual machine instance: $ cubic create mymachine --image ubuntu:noble List all virtual machine instances: $ cubic instances Start an instance: $ cubic start <instance name> Stop an instance: $ cubic stop <instance name> Open a shell in the instance: $ cubic ssh <machine name> Copy a file from the host to the instance: $ cubic scp <path/to/host/file> <machine>:<path/to/guest/file> Copy a file from the instance to the hots: $ cubic scp <machine>:<path/to/guest/file> <path/to/host/file> 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115

use crate::env::Environment;
use crate::error::Error;
use crate::fs::FS;
use crate::instance::Instance;
use crate::ssh_cmd::get_ssh_pub_keys;
use crate::util::SystemCommand;
use std::path::Path;
use std::str;

pub fn bytes_to_human_readable(bytes: u64) -> String {
    match bytes.checked_ilog(1024) {
        Some(1) => format!("{:3.1} KiB", bytes as f64 / 1024_f64.powf(1_f64)),
        Some(2) => format!("{:3.1} MiB", bytes as f64 / 1024_f64.powf(2_f64)),
        Some(3) => format!("{:3.1} GiB", bytes as f64 / 1024_f64.powf(3_f64)),
        Some(4) => format!("{:3.1} TiB", bytes as f64 / 1024_f64.powf(4_f64)),
        _ => format!("{:3.1}   B", bytes as f64),
    }
}

pub fn human_readable_to_bytes(size: &str) -> Result<u64, Error> {
    if size.is_empty() {
        return Result::Err(Error::CannotParseSize(size.to_string()));
    }

    let suffix: char = size.bytes().last().unwrap() as char;
    let size = &size[..size.len() - 1];
    let power = match suffix {
        'B' => 0,
        'K' => 1,
        'M' => 2,
        'G' => 3,
        'T' => 4,
        _ => return Result::Err(Error::CannotParseSize(size.to_string())),
    };

    size.parse()
        .map(|size: u64| size * 1024_u64.pow(power))
        .map_err(|_| Error::CannotParseSize(size.to_string()))
}

pub fn setup_cloud_init(env: &Environment, instance: &Instance) -> Result<(), Error> {
    let fs = FS::new();
    let name = &instance.name;
    let user = &instance.user;

    let user_data_img_path = env.get_user_data_image_file(&instance.name);

    if !Path::new(&user_data_img_path).exists() {
        let meta_data_path = env.get_meta_data_file(&instance.name);
        let user_data_path = env.get_user_data_file(&instance.name);

        fs.create_dir(&env.get_instance_cache_dir(&instance.name))?;

        if !Path::new(&meta_data_path).exists() {
            fs.write_file(
                &meta_data_path,
                format!("instance-id: {name}\nlocal-hostname: {name}\n").as_bytes(),
            )?;
        }

        if !Path::new(&user_data_path).exists() {
            let ssh_pk = if let Ok(ssh_keys) = get_ssh_pub_keys() {
                format!(
                    "\u{20}\u{20}\u{20}\u{20}ssh-authorized-keys:\n{}",
                    ssh_keys
                        .iter()
                        .map(|key| format!("\u{20}\u{20}\u{20}\u{20}\u{20}\u{20}- {key}"))
                        .collect::<Vec<_>>()
                        .join("\n")
                )
            } else {
                String::new()
            };

            fs.write_file(
                &user_data_path,
                format!(
                    "\
                    #cloud-config\n\
                    users:\n\
                    \u{20}\u{20}- name: {user}\n\
                    \u{20}\u{20}\u{20}\u{20}lock_passwd: false\n\
                    \u{20}\u{20}\u{20}\u{20}hashed_passwd: $y$j9T$wifmOLBedd7NSaH2IqG4L.$2J.8E.qE57lxapsWosOFod37djHePHg7Go03iDNsRe4\n\
                    {ssh_pk}\n\
                    \u{20}\u{20}\u{20}\u{20}shell: /bin/bash\n\
                    \u{20}\u{20}\u{20}\u{20}sudo: ALL=(ALL) NOPASSWD:ALL\n\
                    ssh_pwauth: True\n\
                    packages:\n\
                    \u{20}\u{20}- openssh\n\
                    runcmd:\n\
                    \u{20}\u{20}- \
                        apt update; apt install -y qemu-guest-agent socat; \
                        dnf install -y qemu-guest-agent socat; \
                        yes | pacman -S qemu-guest-agent socat; \
                        systemctl enable --now qemu-guest-agent\n\
                "
                )
                .as_bytes(),
            )?;
        }

        SystemCommand::new("mkisofs")
            .arg("-RJ")
            .arg("-V")
            .arg("cidata")
            .arg("-o")
            .arg(&user_data_img_path)
            .arg("-graft-points")
            .arg(format!("/={user_data_path}"))
            .arg(format!("/={meta_data_path}"))
            .run()?;
    }

    Result::Ok(())
}