the power of buildpacks in a platform as-a-service (paas)

The Power of Buildpacks in PaaSThe Platform for the Agile EnterpriseJohn WetherillTechnology Evangelist

Ho Ming LiCloud Engineer

activestate.com/stackato | @activestate | #stackato | activestate.com/blog | Copyright 2014

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What is Stackato?

A secure, stable, and commercially supported Platform-as-a-Service (PaaS) built with open source components such as Cloud Foundry and Docker


Buildpacks Defined

“Cloud Foundry uses buildpacks to transform user-provided artifacts into runnable applications”

Buildpacks can be used to:

• examine user-provided artifacts• download dependencies• configure application properties• specify the application entry point and runtime options


Anatomy of a Buildpack

bin/detect

bin/release

bin/compile

• a buildpack is a network-accessible git repository• repo must contain a bin directory with three scripts


detect script

• determine whether to apply a buildpack• single parameter: BUILD_DIR• script examines this directoryIf buildpack can service this app: • print framework name to stdout • exit 0


sample detect script

#!/bin/sh

if [-f $1/*.js]; then# looks like a node application echo “nodejs” exit 0else exit 1fi


compile script

• perform the buildpack transformation• three parameters: BUILD_DIR CACHE_DIR ENV_DIR

• anything goes here: download dependencies, configure environment, tweak files


sample compile script

#!/bin/shif [ ! -s $1/hello.txt ]; then echo "hello.txt was empty" exit 1fi

cat $1/hello.txt | sed -e "s/[Hh]ello/Goodbye/g" > $1/goodbye.txt


sample compile script

#!/bin/sh

wget something

apt-get install something-else

echo “some: config” > config-file.yml


release script

• release script must output yaml

• specify “addons” • specify Procfile entries (app entrypoint)

(config_vars from Heroku deprecated - use shell-script in app instead)


sample release script

#!/usr/bin/env bash

cat <<EOF---web: java $JAVA_OPT jetty-runner --port $PORTaddons: mysql:devEOF


Procfile

• Not part of buildpack• Specifies app entrypoint• Procfile must be present in app build dir

Sample procfile for Java app:

web: java $JAVA_OPTS jetty-runner --port $PORT


CloudFoundry / Stackato built-in buildpacks

• https://github.com/cloudfoundry/java-buildpack

• https://github.com/cloudfoundry/heroku-buildpack-ruby

• https://github.com/cloudfoundry/heroku-buildpack-nodejs

For Java, Ruby, NodeJS


CloudFoundry Community Buildpacks

https://github.com/cloudfoundry-community/cf-docs-contrib/wiki/Buildpacks


Summary

Procfile

Application source

Buildpack


Minimal buildpack

https://github.com/heroku/heroku-buildpack-hello


Buildpacks and stackato.yml

stackato.yml is used in conjunction with buildpack to:

• specify buildpack location• configure environment• specify staging and runtime hooks• request services• request resources• specify app properties


Specifying Buildpacks

• Buildpack can be selected in stackato.yml:

buildpack: https://github.com/user/mybuildpack.git

• Or as option to stackato command:

stackato push --buildpack ssh://git/buildpack.git


Legacy Buildpack

• special bundled buildpack for “legacy” Stackato apps• provides all frameworks from pre 3.0 Stackato• specify framework and runtime in stackato.yml

name: bottle-py3framework: type: python runtime: python32


Buildpack Catalog

http://buildpack-catalog.stacka.to/buildpacks/


Customizing a buildpack

Why customize?

• alternate versions of runtimes, frameworks, services

• new (or old) runtimes (FORTRAN anyone?)

• complete control of app provisioning process


Customizing a buildpack

Three simple steps:

1. fork an existing buildpack

2. tweak the scripts in bin, add assets

3. specify location of new buildpack in stackato.yml or as parameter to “stackato push --buildpack https://…”


Buildpacks and Licenses

EULAsSoftware license stringsAPI keysCommercial Software

Example:

https://github.com/cloudfoundry/ibm-websphere-liberty-buildpack.git


Buildpack Futures

Better Asset Caching

More services and frameworks

Docker Integration?


Why Enterprises Use Stackato

Faster Time to MarketWith Stackato, developers can get apps to the cloud in minutes, not weeks.

Greater SecurityStackato has been extended and hardened to provide enterprises with tighter security, better compliance, and more control over secure, sensitive data.

Agility and ScalabilityAs usage grows, Stackato scales applications to deliver performance for end-users demand.

Productivity and InnovationStackato automates the configuration, deployment, and management of applications.

FlexibilityStackato gives developers and IT managers the freedom they need. The polyglot nature of Stackato means you can give your developers the flexibility to work with the best choice of language for any task.

Download your own Stackato micro cloud at: http://www.activestate.com/stackato