Lazybones Project Creation Tool

Lazybones was born out of frustration that Ratpack does not and will not have a command line tool that will bootstrap a project. It's a good decision for Ratpack, but I'm lazy and want tools to do the boring stuff for me.

The tool is very simple: it allows you to create a new project structure for any framework or library for which the tool has a template. You can even contribute templates by sending pull requests to this GitHub project or publishing the packages to the relevant Bintray repository (more info available below).

The concept of Lazybones is very similar to Maven archetypes, and what Yeoman does for web applications. Lazybones also includes a sub-templates feature that resembles the behaviour of Yeoman's sub-generators, allowing you to generate optional extras (controllers, scaffolding etc.) inside a project.

Developers

• Peter Ledbrook
• Kyle Boon
• Tommy Barker

Contributors

• Luke Daley
• Tomas Lin
• Russell Hart
• Dave Syer
• Andy Duncan

Running it

Grab lazybones from gvm:

gvm install lazybones

or alternatively, grab the distribution from Bintray, unpack it to a local directory, and then add its 'bin' directory to your PATH environment variable.

Creating projects

To create a new project, run

lazybones create <template name> <template version> <target directory>

So if you wanted to create a skeleton Ratpack project in a new 'my-rat-app' directory you would run

lazybones create ratpack-lite 0.1 my-rat-app

The version is optional and if you leave it out, Lazybones will install the latest version of the template it can find.

Named templates are all stored on Bintray. By default, Lazybones searches for templates in the pledbrook/lazybones-templates repository, but you can use other Bintray repositories by adding some configuration - set the Custom Repositories section under Configuration later in this document.

You're not limited to only Bintray as you can install templates directly from a URL too:

lazybones create http://dl.bintray.com/kyleboon/lazybones/java-basic-template-0.1.zip my-app

Of course it can be pretty laborious copying and pasting URLs around, so Lazybones allows you to configure aliases for URLs that you use frequently. By adding the following configuration to your Lazybones settings file, ~/.lazybones/config.groovy (see below for more details on this), you can install the template by name:

templates {
    mappings {
        myTmpl = "http://dl.bintray.com/..."
    }
}

In other words, you could now run

lazybones create myTmpl my-app

Note that when using the URL option, there is no need to specify a version. You should also be aware that mappings take precedence, i.e. if a mapping has the same name as an existing template, the mapping is used. This essentially creates a simple override mechanism.

There is just one more thing to say about the create command: by default it creates the specified directory and puts the initial project in there. If you want to unpack a template in the current directory instead, for example if you have already created the project directory, then just pass '.' as the directory:

lazybones create ratpack .

Once you have created a new project from a template, you may notice that the project directory contains a .lazybones sub directory. You may delete this, but then you won't be able to use the generate command (see next section) if the project template has support for it.

Many project templates request information from you, such as a project name, a group ID, a default package, etc. If this is the umpteenth time you have created a project from a given template, then answering the questions can become tedious. There is also the problem of scripting and automation when you want to create a project without user intervention. The solution to both these issues is to pass the values on the command line:

lazybones create ratpack 0.2 ratapp -Pgroup=org.example -Ppackage=org.example.myapp

The -P option allows you to pass property values into the project templates without user intervention. The key is to know what the property names are, and that comes down to the project template. At the moment, the best way to find out what those properties are is to look at the post-install script itself.

The last option to mention is --with-git which will automatically create a new git repository in the project directory. The only requirement is that you have the git command on your path.

Sub-templates

As of Lazybones version 0.7, project templates can incorporate sub-templates. Imagine that you have just created a new web application project from a template and that template documents that you can create new controllers using a sub- template named controller. To use it, just cd into the project directory and run

lazybones generate controller

This will probably ask you for the name of the controller and its package before generating the corresponding controller file in your project. You can reuse the command to create as many controllers as you need.

As with the create command, you can also pass in property values on the command line if the sub-template is parameterised:

lazybones generate controller -Ppackage=org.example.myapp -Pclass=Book

The last option available to you as a user is template qualifiers. These only work if the sub-template supports them, but they allow you to pass additional information in a concise way:

lazybones generate artifact::controller

In this case, the template name is artifact, but we have qualified it with an extra controller. You can pass in as many qualifiers as you want, you just separate them with ::.

Note that you do not specify a version with the generate command. This is because the sub-templates are embedded directly in the project template, and so there can only be one version available to you.

Finding out what templates are available

To see what templates you can install, run

lazybones list

This will list all aliases and remote templates. If you want to see what templates you have cached locally, run

lazybones list --cached

In fact, --cached is implied if Lazybones can't connect to the internet.

You can also find out more about a template through the info command:

lazybones info <template name>

This will print a description of the template and what versions are available for it. If you're offline, this will simply display an error message.

Configuration

Lazybones will run out of the box without any extra configuration, but the tool does allow you to override the default behaviour via a fixed set of configuration options. These options can be provided in a number of ways following a set order of precedence:

1. System properties of the form lazybones.*, which can be passed into the app via either JAVA_OPTS or LAZYBONES_OPTS environment variables. For example:

   env JAVA_OPTS="-Dlazybones.config.file=/path/to/my-custom-default-config.groovy" lazybones ...

Highest precedence, i.e. it overrides all other sources of setting data.

2. User configuration file in $USER_HOME/.lazybones/config.groovy. This is parsed using Groovy's ConfigSlurper, so if you're familiar with that syntax you'll be right at home. Otherwise, just see the examples below.

3. (Since 0.8) A JSON configuration file in $USER_HOME/.lazybones/managed-config.groovy that is used by the config commands. You can edit it this as well.

4. A Groovy-based default configuration file that is provided by the application itself, but you can specify an alternative file via the lazybones.config.file system property.

Lazybones also provides a convenient mechanism for setting and removing options via the command line: the config command.

Command line configuration

The config command provides several sub-commands that allow you to interact with the persisted Lazybones configuration; specifically, the JSON config file. You run a sub-command via

lazybones config <sub-cmd> <args>

where <sub-cmd> is one of:

• set <option> <value> [<value> ...]

  Allows you to change the value of a configuration setting. Multiple values are treated as a single array/list value. The new value replaces any existing one.

• add <option> <value>

  Appends an extra value to an existing array/list setting. Reports an error if the setting doesn't accept multiple values. If the setting doesn't already have a value, this command will initialise it with an array containing the given value.

• clear <option>

  Removes a setting from the configuration, effectively reverting it to whatever the internal default is.

• show [--all] <option>

  Shows the current value of a setting. You can use the --all argument (without a setting name) to display all the current settings and their values.

• list

  Displays all the configuration settings supported by Lazybones.

So what configuration settings are you likely to customise?

Custom repositories

Lazybones will by default download the templates from a specific Bintray repository. If you want to host template packages in a different repository you can add it to Lazybone's search path via the bintrayRepositories setting:

bintrayRepositories = [
      "kyleboon/lazybones",
      "pledbrook/lazybones-templates"
]

If a template exists in more than one repository, it will be downloaded from the first repository in the list that it appears in.

Package aliases

If you regularly use a template at a specific URL rather than from Bintray, then you will want to alias that URL to a name. That's where template mappings (or aliases) come in. The aliases are defined as normal settings of the form

templates.mappings.<alias> = <url>

In a Groovy configuration file, you can define multiple aliases in a block:

templates {
    mappings {
        test = "http://dl.dropboxusercontent.com/u/29802534/custom-ratpack.zip"
        after = "file:///var/tmp/afterburnerfx-2.0.0.zip"
    }
}

Alternatively, add them from the command line like this:

lazybones config set templates.mappings.after file:///var/tmp/afterburnerfx-2.0.0.zip

The aliases will always be available to you until you remove them from the persisted configuration.

General options

These are miscellaneous options that can be overridden on the command line:

// <-- This starts a line comment
// Set logging level - overridden by command line args
options.logLevel = "SEVERE"

The logging level can either be overridden using the same logLevel setting:

lazybones --logLevel SEVERE info ratpack

or via --verbose, --quiet, and --info options:

lazybones --verbose info ratpack

The logging level can be one of:

• OFF
• SEVERE
• WARNING
• INFO
• FINE
• FINEST
• ALL

Building it

This project is split into two parts:

1. The lazybones command line tool; and
2. The project templates.

The command line tool

The command line tool is created via Gradle's application plugin. The main class is uk.co.cacoethes.lazybones.LazyBonesMain, which currently implements all the sub-commands (create, list, etc.) as concrete methods.

The main class plus everything else under src/main is packaged into a lazybones JAR that is included in the distribution zip. The application Gradle plugin generates a lazybones script that then runs the main class with all required dependencies on the classpath.

To build the distribution, simply run

./gradlew distZip

The project templates

The project templates are simply directory structures with whatever files in them that you want. Ultimately, the template project directories will be zipped up and stored on Bintray. From there, lazybones downloads the zips on demand and caches them in a local user directory (currently ~/.lazybones/templates).

If you want empty directories to form part of the project template, then simply add an empty .retain file to each one. When the template archive is created, any .retain files are filtered out (but the containing directories are included).

To package up a template, simply run

./gradlew packageTemplate<TemplateName>

The name of the project template comes from the containing directory, which is assumed to be lowercase hyphenated. The template name is the equivalent camel case form. So the template directory structure in src/templates/ratpack-lite results in a template called 'RatpackLite', which can be packaged with

./gradlew packageTemplateRatpackLite

The project template archive will be created in the build directory with the name '-template-.zip'. See the small section below on how the template version is derived.

You can also package all the templates in one fell swoop:

./gradlew packageAllTemplates

Once a template is packaged up, you can publish it to a generic (non-Maven) Bintray repository by running

./gradlew publishTemplate<TemplateName>

This will initially fail, because the build does not know where to publish to. That's quickly fixed by adding a gradle.properties file in the root of this project that contains at least these properties:

repo.username=your_bintray_username
repo.apiKey=your_bintray_apikey

You can then publish new versions of templates whenever you want. Note that you cannot republish with this mechanism, so remember to increment the version if you need to.

Finally, you can publish the whole shebang (unusual) with

./gradlew publishAllTemplates

If you don't want to publish your template you can install it locally using the installTemplate rule.

 ./gradlew installTemplate<TemplateName>

This will install the template to ~/.lazybones/templates so that you can use it without moving it to bintray first.

And that's it for the project templates.

Template versions

You define the version of a template by putting a VERSION file in the root directory of the template that contains just the version number. For example, you specify a version of 1.2.8 for the ratpack-lite template by adding the file src/templates/ratpack-lite/VERSION with the contents

1.2.8

That's it! The VERSION file will automatically be excluded from the project template archive.

Contributing templates

Read the Template Developers Guide for information on how to create and publish Lazybones templates.