lein-ezbake

EZBake is a leiningen plugin that integrates multiple Trapperkeeper services and their config files into a single uberjar and stages them in preparation for packaging.

Using

To get started using EZBake, please add it to the :plugins key in your project.clj:

{:plugins [[puppetlabs/lein-ezbake "0.2.3"]]}

Before you can get started using it, however, there may be some additional configuration necessary.

Configuring

{:lein-ezbake {

  ; Configures how lein-ezbake manages resources. "Resources" primarily refers
  ; to the templates ezbake uses to build packages.
  :resources {

    ; The resources type indicates where lein-ezbake gets resources from.
    ; Currently only resources stored in the lein-ezbake jar can be used. Future
    ; versions of lein-ezbake may support pulling these resources instead from a
    ; specific version of some git repository.
    :type :jar

    ; This directory refers to the location in the current project where
    ; resources will be dumped.
    :dir "tmp/config"}

  ; This is the directory where lein-ezbake will look for additional
  ; configuration files to copy into the staging directory.
  :config-dir "config"

  ; These variables are available to either modify the behavior of lein-ezbake
  ; in various ways or to populate values in template files.
  :vars {
    :user "puppet"
    :group "puppet"
    :start-timeout "120"
    :build-type "foss"
    :java-args "-Xms2g -Xmx2g -XX:MaxPermSize=256m"}}}

In addition to this standard configuration, there are two primary use cases for lein-ezbake which lead to different configuration parameters. The differences are considered in further depth under Standalone Projects and Composite Projects.

Standalone vs Composite EZBake Projects

EZBake projects generally fall under two categories based on the situations in which they are used: standalone and composite.

A Standalone ezbake project is one in which the code for one of the trapperkeeper services packaged by lein-ezbake is included in the same project repository that is used to define the ezbake configuration values. The prototypical example of this type of project is Puppet Server.

A Composite ezbake project is one in which the primary purpose of the repository where the ezbake configuration values are defined is to compose multiple trapperkeeper services into a single package using ezbake. The prototypical example of this type of project is pe-console-services.

Standalone

Since a standalone ezbake project is often defined in the same repository as one of the TK services it is intended to package and therefore shares a project.clj, it may be necessary to overwrite some values used by ezbake when creating the staging directory.

Specifically, the :name and :dependencies keys may need to be replaced as in the Puppet Server example below. The :name replacement is necessary to avoid name collision when an ezbake project also consists of clojure code that defines its own TK services and the Maven artifact name does not match the desired package name.

{:profiles {
  :ezbake {
    :dependencies ^:replace
      [[puppetlabs/puppet-server "0.4.2-SNAPSHOT"]
       [puppetlabs/trapperkeeper-webserver-jetty9 "0.9.0"]
       [org.clojure/tools.nrepl "0.2.3"]]
    :name "puppetserver"}}}

Note that it is necessary here to use the ^:replace metadata on the :dependencies list since Leiningen's default behavior is to append dependencies defined in a lein profile.

Note that the symble :ezbake is not strictly necessary here.

Composite

Composite ezbake projects usually do not define their own services but rather provide a list of dependencies which themselves define TK services. Because of this it is not strictly necessary to define a profile such as :ezbake shown above; although it is conceivable that such a composite project may define its own services, it is unlikely and ill-advised because no one likes blurred lines in architectural diagrams. Just look at the Leaning Tower of Pisa.

Running

Running ezbake works much like any other Leiningen plugin or built-in task. However, if you are working on a standalone project it will be necessary to use a profile such as the :ezbake profile as shown in the configuration above.

stage

The stage action is useful for when you'd like to install an ezbake uberjar from source or inspect its contents without waiting for the build step to complete.

lein with-profile ezbake ezbake stage

This will create an ephemeral git repository at ./target/staging with staged templates ready for consumption by the build step.

build

lein with-profile ezbake ezbake build

This will do everything the stage action does and then call the external builder defined for this project. Currently, the only builder supported is Puppetlabs' Packaging tool.

build with a different profile

lein with-profile ezbake,pe ezbake build

This is an example of how a project might differentiate between "foss" and "pe" packages. The :pe profile may define different values for :lein-ezbake or for anything that might be found in the :ezbake profile. This is primarily useful for projects that need to build their PE and FOSS packages from the same repository.

Testing

After building packages it is often necessary to install those packages in live environments on the OSes supported by the ezbake templates. For this purpose Puppetlabs' Beaker is the, uh, choice tool of discerning developers.