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.

EZBake branches

The branching strategy is now covered in the Branching Strategy page on the EZBake wiki.

Minimum Trapperkeeper version dependencies

EZBake 1.0 and later utilize the feature in Trapperkeeper to monitor service start and reload status. For this reason, the application being packaged must include Trapperkeeper 1.5.1 or later. If an earlier version is used instead, the service will fail to be started properly due to the lack of support for the -r | --restart-file command line option in the earlier Trapperkeeper versions.

The failure message would be written to the /var/log/puppetlabs/<app>/<app>-daemon.log file -- for sysvinit / upstart -- or journal -- for systemd -- with text which looks like this:

Error(s) occurred while parsing command-line arguments: Unknown option: "--restart-file"

Using

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

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"

  ; If specified, this is a directory where lein-ezbake will look for additional
  ; configuration files will end up under the install directory under /opt. It's
  ; intended for configuration files that an end user should not edit
  :system-config-dir "system-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"
    :logrotate-enabled true}}}

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.

Additional Uberjars

Some projects might have a use case for automatically fetching a versioned jar from an external repository that needs to be placed into the package and be available after installation.

The :additional-uberjars setting can be set to a list of project coordinates that will be resolved and have uberjars built from them. For example:

{:lein-ezbake {
  :additional-uberjars [[puppetlabs/puppetserver "2.7.2"]]
...}}

This would result in a puppetserver uberjar being built, and the jar being placed in the same directory as your project's own uberjar after installation.

The filename of the built uberjar is determined by what value :uberjar-name is set to in its project.clj

EZBake will attempt to resolve the coordinates of these external uberjars using the repositories specified in the :repositories key of your project.clj

cli-defaults.sh

cli-defaults.sh is intended to be a file from which default shell script variables can be defined by a project, and be loaded by EZBake's cli-app script. That is, the script which is run when commands like service my-project start are called.

This differs from the default files, which also get loaded by cli-app, in that a project has no control over what goes into default. cli-defaults.sh is under the control of your project.

For cli-defaults.sh to be used, it needs to exist at resources/ext/cli_defaults/cli-defaults.sh.erb in your standalone project. If placed in an uberjar, it will not be recognized. Since it is an erb template, it will have access to the variables in ezbake.rb

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. If the project being staged has a SNAPSHOT version, then a snapshot build will be deployed to the project's configured snapshots repository (typically our internal artifact repository server at artifactory.delivery.puppetlabs.net), in order to ensure our builds are reproducible. This can be avoided by setting the EZBAKE_NODEPLOY environment variable to any value. (If you set this environment variable in a build pipeline, you will be severely punished by the Angel of Build Reproducibility.)

If the project or any of its dependencies have a SNAPSHOT version, but a deployed snapshot artifact matching that version cannot be found in the configured repositories (for example, because they have only been installed locally), then EZBake will throw an error to prevent an unreproducible build. If you're testing local changes, you can avoid this check by setting the EZBAKE_ALLOW_UNREPRODUCIBLE_BUILDS environment variable to any value. (If you set this in a build pipeline, bad things will happen, possible to a future version of yourself.)

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, this is tied to internal infrastructure at Puppet. If you want to run an ezbake build on your own infrastructure, see the local-build option below. Starting in version 1.6.0 build requires jenkins authorization to be passed in at runtime. This should be set in the JENKINS_USER_AUTH environment variable to either '' or ':'.

build for PE

For PE builds, you need to set an environment variable PE_VER to reflect the version of PE you're building a package for. e.g.:

PE_VER=2016.3 lein with-profile ezbake ezbake build

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.

local-build

lein with-profile ezbake ezbake local-build

This will do everything the stage action does and then call the local builder defined for this project. This will build .deb and .rpm packages for the project on your local machine using FPM. To build successfully you'll need the FPM gem installed. You'll also need java and leiningen. To build RPMs you'll want to be on some sort of RPM-based system as you need RPM build tools. To build RPMs for SLES you'll need to have the systemd-rpm-macros rpm installed. Building .debs doesn't require anything special.

Packages will end up in the output directory. RPM targets can be overwritten by setting the MOCK environment variable and deb targets can be overwritten by setting the COW environment variable. These variables should be space-separated lists of rpm(MOCK) and deb(COW) platforms.

docker-build

lein with-profile ezbake ezbake docker-build

This will build a container image using the settings in the :docker section of the :lein-ezbake config in project.clj. See Building container images below for more detail.

manifest

lein with-profile ezbake ezbake manifest

The manifest action is useful when comparing multiple ezbake builds without actually building an artifact.

This generates a json file at ext/build_metadata.json which contains information about the project. This information has project dependencies and their versions, any dependencies of those dependencies, ezbake version, and the git sha of the project being built. Downstream packaging tools may decide to make use of this file to track what is in a build in a more programmatic manner with this artifact.

Note: This step is automatically ran as part of the stage action and as a result also ran in the build action.

Packaging Configuration Files

By default, in the final packages produced by an ezbake build, there will be a "config" directory (usually /etc/puppetlabs/<ezbake-project-name>) that contains all of the final configuration files for the ezbake application.

bootstrap-source

The bootstrap-source setting can be one of:

• (Default) :bootstrap-cfg
• :services-d

If the :bootstrap-source setting is set to :services-d, there will also be an additional configuration directory under the installation directory: /opt/puppetlabs/server/apps/{project-name}/config/ This directory will then be used to hold a services.d/ directory that contains bootstrap files. Usually this will be for bootstrap entries the application could not run without, and which should not be modified by the user. See Bootstrap Files

EZBake will assemble the contents of this directory from two sources:

1. Config files embedded in the jars of any of the dependencies
2. Config files local to the ezbake project

Config files embedded in jars of dependencies

If the jar produced by any of the dependencies of the ezbake project contains a directory called ext/config/, then any files therein will be included in the final conf.d directory of the ezbake package.

This is useful if your project uses a "composite" ezbake build. For example, we build pe-puppetserver packages from a composite project called pe-puppetserver, which does not contain any code; it's a project that just exists for use with ezbake, to compose other things together. One of the dependencies that it brings in is puppet-server, which is the main codebase where all of the OSS Puppet Server code lives. The puppet-server jar includes some config files, such as puppetserver.conf, which are specific to Puppet Server. These config files won't change based on packaging, and it is useful/important to keep them in sync with the related Puppet Server source code, so they live in the upstream repos and ezbake retrieves them from the jar files.

Config files local to the ezbake project

EZBake supports a setting in the :lein-ezbake portion of your project.clj called :config-dir. The default value if you do not provide this setting is config. The value of this setting tells ezbake where to look for local config files that may vary based on the packaging task at hand; so, for example, files like webserver.conf and web-routes.conf may vary depending on what services you are composing together at build time, so they are not guaranteed to be static based on the upstream code.

To build on our pe-puppetserver example above; this composite ezbake project brings in services like the file sync service and code manager, and we need to build out the web-routes.conf file based on the list of all of the services that we are composing together. Thus, this type of config file needs to live in the repo of the ezbake build project itself, and wouldn't make sense to try to include inside of the 'puppet-server' jar, since we could be building many permutations of packages that contain Puppet Server and can't know ahead of time what a valid web-routes.conf will look like.

tl;dr on where to put config files

The rule of thumb is:

• For config files that are specific to an individual project, such as the OSS Puppet Server project, the files should be embedded in the jar under ext/config. e.g.: ext/config/conf.d/puppetserver.conf.
• For config files that are specific to the packaging task (usually this implies a composite ezbake build), the files should live in the repo of the ezbake packaging project; e.g. in the pe-puppetserver composite project, there is a directory at the root called config, and this will contain files like config/conf.d/web-routes.conf.

Bootstrap Files

There are two ways of specifying a set of services to bootstrap your TK application with:

1. A single bootstrap.cfg file in your project's :config-dir directory
2. Two services.d directories which can contain any number of *.cfg files that will be merged together

This choice is controlled by the :bootstrap-source setting. The default value of :bootstrap-cfg makes ezbake look for a single file called bootstrap.cfg directly under your :config-dir. Setting :booststrap-source to :services-d will cause ezbake to construct service init scripts that pass TK two directories, usually /etc/puppetlabs/{project-name}/services.d/, and /opt/puppetlabs/server/apps/{project-name}/config/services.d.

This means that in your TK project, you'll need to at least put a service.d/ directory in your :config-dir, and optionally another in your :system-config-dir. You might want to use the system-config-dir if you are concerned about users editing files under /etc.

For example, with the default lein-ezbake settings, your directories might look like this:

.
├── config
│   └── services.d
│       ├── more_services.cfg
│       ├── other_services.cfg
│       └── some_services.cfg
└── system-config
    └── services.d
        └── really_important_services.cfg

Subcommands

EZBake packages can install "subcommands" which can be run by the user via a command-line interface (CLI). The template defines the wrapper CLI "application" through which the subcommands are run. The cli-app.erb template is converted into a shell script which resides at /opt/puppetlabs/server/bin/<package-name> after package install. Subcommands are also implemented as erb templates, residing in separate files under the namespace. The subcommand erb templates are converted into shell scripts which reside at /opt/puppetlabs/server/apps/<package-name>/cli/apps after package install.

A user can invoke a CLI subcommand by passing the name of the subcommand as the first argument to the wrapper CLI "application". For example, a user could type the following to execute the foreground subcommand:

/opt/puppetlabs/server/bin/<package-name> foreground

A Clojure project which uses lein-ezbake as a plugin can provide its own custom subcommands as erb templates under the project's ./resources/ext/cli directory. The erb templates are converted into shell scripts at package build time.

EZBake includes the following subcommands in every package which is built:

Foreground

This starts up the Trapperkeeper application under Java - similar to what the service framework would do when service <app> start is run, only with the application being run in the shell foreground rather than as a daemon. stdout and stderr output from the application will appear in the shell foreground, as opposed to the daemon log or journal (which would happen when the application is run as a daemon instead).

Any additional arguments given to the subcommand are passed along as command-line options to the Java command line for the Trapperkeeper application. For example, the following command line would run the application in foreground in "debug" mode, using Trapperkeeper's '--debug' CLI argument:

/opt/puppetlabs/server/bin/<package-name> foreground --debug

When the --debug flag is given to the foreground subcommand, all application log output is printed both to the standard log locations configured in the application's global log configuration and to stdout for the shell in which foreground is being run.

The Java application is run under the same user as the service framework would use, set via the user setting in the project's EZBake configuration.

Start

This starts up the Trapperkeeper application as a background process. This is the same script which is invoked when the service is started via the service framework. Note that when the service is started is run via sourcing the 'start' subcommand directly, though, that it will not be fully daemonized and runs as whatever user the CLI subcommand is started with - not necessarily the same as what is set for the user setting in the project's EZBake configuration.

Example:

/opt/puppetlabs/server/bin/<package-name> start

The script returns an exit code of 0 if the service is successfully started or if the service had already been started before the script was run. Note that the 'start' subcommand does not start a second instance of the application if one is already running.

The script returns an exit code of 1 if the service fails to start. The script waits for the server to start for up to the number of seconds specified by the START_TIMEOUT environment variable, if specified, or the value of the start-timeout setting in the project's EZBake configuration. If this time limit is exceeded, the script attempts to kill the service before exiting.

Stop

This stops any currently running instance of the Trapperkeeper application. This is the same script which is invoked when the service is stopped via the service framework.

Example:

/opt/puppetlabs/server/bin/<package-name> stop

The script returns an exit code of 0 if the service is successfully stopped or if the service was already not running at the time the script is run.

The script returns an exit code of 1 if the service fails to stop. The script waits for the server to stop for up to the number of seconds specified by the SERVICE_STOP_RETRIES environment variable, if specified, or the value of the stop-timeout setting in the project's EZBake configuration.

Reload

This reloads any currently running instance of the Trapperkeeper application. This is the same script which is invoked when the service is reloaded via the service framework.

The reload is triggered by sending a SIGHUP signal to the Java process running the Trapperkeeper service. Trapperkeeper handles the SIGHUP by calling stop on the application, followed by calling start on the application. When the start call has finished, Trapperkeeper increments a start counter in a restart-file on disk. The reload script polls in a loop for the contents of the restart-file. When the contents have changed, the reload script determines that the reload is successful and the script returns. For more information on the restart-file feature in Trapperkeeper, see in the Trapperkeeper documentation.

Example:

/opt/puppetlabs/server/bin/<package-name> reload

The script returns an exit code of 0 if the service is successfully reloaded.

The script returns an exit code of 1 if the service fails to reload. If the service is stopped at the time the script is run, the script will return an exit code of 1 without attempting to start the service. If the service is running and the SIGHUP signal can successfully be sent, the script waits for the server to reload for up to the number of seconds specified by the RELOAD_TIMEOUT environment variable, if specified, or the value of the reload-timeout setting in the project's EZBake configuration. The script returns an exit code of 1 if the timeout is reached or if the process dies during the reload attempt.

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.

Building container images

EZBake can also be used to build docker images. The command lein ezbake docker-build can be used to build an image using config specified in <config-dir>/docker. The result will be an image derived from the openjdk:8-jre-alpine base image, with an entrypoint set to the correct java invocation to run the service. Config files will be located in /config/conf.d and the bootstrap file in /config/bootstrap.cfg. The project uberjar and any additional uberjars will be in /src.

Some variables can be set under the :docker key in project.clj:

{:lein-ezbake {
  :config-dir "config"
  :vars {
    :docker {
      ; Specify ports to be exposed in the container
      :ports [8140]
      ; Tag the image with a specific name. Defaults to the project name
      :image-name "myproject"
      ; Override the base image. Defaults to openjdk:8-jre-alpine
      :base-image "openjdk:8-jre-alpine"}}}}

This feature is currently experimental.

Maintainers

See MAINTAINERS file