jashandeep-sohi / cargo-generate

cargo, make me a project

cargo-generate

cargo, make me a project

cargo-generate is a developer tool to help you get up and running quickly with a new Rust project by leveraging a pre-existing git repository as a template.

Here's an example of using cargo-generate with this template:

Installation

Using cargo with system's OpenSSL

cargo install cargo-generate

See the openssl-sys crate readme on how to obtain the OpenSSL library for your system. Alternatively, use the vendored-openssl flag if you do not want to install OpenSSL.

Using cargo with vendored OpenSSL

NOTE: vendored-openssl requires the following packages to be installed:

• libssl-dev
• gcc
• m4
• ca-certificates
• make
• perl

cargo install cargo-generate --features vendored-openssl

Manual Install:

1. Download the binary tarball for your platform from our releases page.

2. Unpack the tarball and place the binary cargo-generate in ~/.cargo/bin/

Usage

Standard usage is to pass a --git flag to cargo generate or short cargo gen. This will prompt you to enter the name of your project.

NOTE: cargo gen requires an cargo alias configuration

cargo generate --git https://github.com/githubusername/mytemplate.git

You can also pass the name of your project to the tool using the --name or -n flag:

cargo generate --git https://github.com/githubusername/mytemplate.git --name myproject

git over ssh

New in version 0.7.0 is the support for both public and private and ssh git remote urls. For example:

cargo generate --git [email protected]:rustwasm/wasm-pack-template.git --name mywasm

leads to the same result as:

cargo generate --git https://github.com/rustwasm/wasm-pack-template.git --name mywasm

as well as:

cargo generate --git rustwasm/wasm-pack-template --name mywasm

NOTE: you can pass a custom ssh identity file with via -i | --identity like -i ~/.ssh/id_rsa_other

http(s) proxy

New in version 0.7.0 is automatic proxy usage. So, if http(s)_PROXY env variables are provided, they will be used for cloning a http(s) template repository.

Favorites

Favorite templates can be defined in a config file, that by default is placed at $CARGO_HOME/cargo-generate. To specify an alternative configuration file, use the --config <config-file> option.

Each favorite template is specified in its own section, e.g.:

[favorites.demo]
description = "Demo template for cargo-generate"
git = "https://github.com/ashleygwilliams/wasm-pack-template"
branch = "master"

Both branch and description are optional, and the branch may be overridden by specifying --branch <branch> on the command line.

When favorites are available, they can be generated simply by invoking:

cargo gen <favorite>

or slightly more involved:

cargo generate demo --branch master --name expanded_demo

NOTE: when <favorite> is not defined in the config file, it is interpreted as a git repo like as if --git <favorite>

Templates

Templates are git repositories whose files contain placeholders. The current supported placeholders are:

• {{authors}}

  this will be filled in by a function borrowed from Cargo's source code, that determines your information from Cargo's configuration.

• {{project-name}}

  this is supplied by either passing the --name flag to the command or working with the interactive CLI to supply a name.

• {{crate_name}}

  the snake_case_version of project-name

• {{crate_type}}

  this is supplied by either passing the --bin or --lib flag to the command line, contains either bin or lib, --bin is the default

• {{os-arch}}

  contains the current operating system and architecture ex: linux-x86_64

Additionally, all filters and tags of the liquid template language are supported. For more information, check out the Liquid Documentation on Tags and Filters.

You can also add a .genignore file to your template. The files listed in the .genignore file will be removed from the local machine when cargo-generate is run on the end user's machine. The .genignore file is always ignored, so there is no need to list it in the .genignore file.

Here's a list of currently available templates. If you have a great template that you'd like to feature here, please file an issue or a PR!

Example for --bin and --lib

A template could be prepared in a way to act as a binary or a library. For example the Cargo.toml might look like:

[package]
# the usual stuff

[dependencies]
{% if crate_type == "bin" %}
structopt = "0.3.21"
{% endif %}
# other general dependencies

{% if crate_type == "bin" %}
[[bin]]
path = "src/main.rs"
name = "{{crate_name}}-cli"
{% endif %}

Now a user of this template could decide weather they want the binary version by passing --bin or use only the library version by passing --lib as a command line argument.

Template defined placeholders

Sometimes templates need to make decisions. For example one might want to conditionally include some code or not. Another use case might be that the user of a template should be able to choose out of provided options in an interactive way. Also, it might be helpful to offer a reasonable default value that the user just simply can use.

Since version 0.6.0 it is possible to use placeholders in a cargo-generate.toml that is in the root folder of a template.
Here an example:

[placeholders.hypervisor]
type = "string"
prompt = "What hypervisor to use?"
choices = ["uhyve", "qemu"]
default = "qemu"

[placeholders.network_enabled]
type = "bool"
prompt = "Want to enable network?"
default = true

As you can see the placeholders configuration section accepts a table of keywords that will become the placeholder name.

In this example the placeholder hypervisor and network_enabled will become template variables and can be used like this:

{% if network_enabled %}
use std::net::TcpListener;

fn main() {
    let listener = TcpListener::bind("0.0.0.0:8080").unwrap();
    loop {
        let (conn, addr) = listener.accept().unwrap();
        println!("Incoming Connection from {}", addr);
        std::io::copy(&mut &conn, &mut &conn).unwrap();
    }
}
{% else %}
fn main() {
    println!("Hello Rusty Hermit 🦀");
}
{% endif %}

Tip: similar to dependencies in the Cargo.toml file you can also list them as one liners:

[placeholders]
hypervisor = { type = "string", prompt = "What hypervisor to use?", choices = ["uhyve", "qemu"], default = "qemu" }
network_enabled = { type = "bool", prompt = "Want to enable network?", default = true }

prompt property

The prompt will be used to display a question / message for this very placeholder on the interactive dialog when using the template.

🤷  What hypervisor to use? [uhyve, qemu] [default: qemu]:

type property

A placeholder can be of type string or bool. Boolean types are usually helpful for conditionally behaviour in templates.

choices property (optional)

A placeholder can come with a list of choices that the user can choose from. It's further also validated at the time when a user generates a project from a template.

choices = ["uhyve", "qemu"]

default property (optional)

A default property must mach the type (string | bool) and is optional. A default should be provided, to ease the interactive process. As usual the user could press and the default value would simply be taken, it safes time and mental load.

default = 'qemu'

regex property (optional)

A regex property is a string, that can be used to enforce a certain validation rule. The input dialog will keep repeating until the user entered something that is allowed by this regex.

Placeholder Examples

An example with a regex that allows only numbers

[placeholders]
phone_number = { type = "string", prompt = "What's your phone number?", regex = "[0-9]+" }

Default values for placeholders from a file

For automation purposes the user of the template may provide provide a file containing the values for the keys in the template by using the --template-values-file flag.

The file should be a toml file containing the following (for the example template provided above):

[values]
hypervisor = "qemu"
network_enabled = true

Include / Exclude

Templates support a cargo-generate.toml, with a "template" section that allows you to configure the files that will be processed by cargo-generate. The behavior mirrors Cargo's Include / Exclude functionality, which is documented here. If you are using placeholders in a file name, and also wish to use placeholders in the contents of that file, you should setup your globs to match on the pre-rename filename.

[template]
include = ["Cargo.toml"]
# include and exclude are exclusive, if both appear we will use include
exclude = ["*.c"]

Cargo gen - alias

cargo gen requires an cargo alias to be configured in your $HOME/.cargo/config like this:

[alias]
gen = "generate"

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions. If you want to contribute to cargo-generate, please read our CONTRIBUTING notes.