Buildpacks

04 What are buildpacks?

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Feature

As a CF hero
I want a simple static website
So that I can focus on building my product

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What are buildpacks?

A Cloud Foundry component that 
resolves your app's runtime dependencies

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Why buildpacks?

• Simplify app deployment - focus on your code
• Fewer files, quicker app deploys
• Produce self-contained, runnable app artefacts

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What does a buildpack do?

• Input is the application code
• Examines application and fulfils dependencies
• Output is a droplet
• Metadata output defines ENV vars and start command

Each buildpack participates in election

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How does a buildpack work?

1. bin/detect
2. bin/compile
3. bin/release

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Where does the buildpack run?

• Uses the host kernel with a rootfs (jeos)
• Default rootfs is cflinuxfs2 (based on Ubuntu 14.04 Trusty)
• Buildpack execution and app runtime are in containers
• Cloud Foundry uses Garden for containerisation

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Cloud Foundry 
deployment flow 
revisited

1. Developer pushes application
2. Ordered list of buildpacks detect app compatibility
3. Winning buildpack runs compile and release (staging)
4. Resulting droplet is store in blobstore
5. Droplets are deployed in containers for running apps

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How many types of buildpacks?

1. Default buildpacks
2. Community buildpacks
3. Heroku buildpacks
4. Custom buildpacks

Online and Offline

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1. Default buildpacks

$ cf buildpacks

buildpack              position   filename
ruby_buildpack         1          ruby_buildpack-cached-v1.6.7
nodejs_buildpack       2          nodejs_buildpack-cached-v1.5.0
java_buildpack         3          java-buildpack-v3.2
go_buildpack           4          go_buildpack-cached-v1.6.2
liberty_buildpack      5          liberty_buildpack
python_buildpack       6          python_buildpack-cached-v1.5.1
php_buildpack          7          php_buildpack-cached-v4.1.4
staticfile_buildpack   8          staticfile_buildpack-cached-v1.2..
binary_buildpack       9          binary_buildpack-cached-v1.0.1

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2. Community buildpacks

github.com/cloudfoundry-community

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3. Heroku buildpacks

• CF buildpacks are based on them
• They are interchangeable* (mostly)

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4. Custom buildpacks

• Your own language deserves its own buildpack
• As simple or as complicated as you want

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Static buildpack

# From the training home directory:
$ cd 04-buildpacks/static-app
$ cf push

$ cf app static-app

     state     since        cpu    memory        disk
#0   running   2015-11-02   0.0%   6.5M of 16M   33.6M of 64M

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Scale app with ease

$ cf scale static-app -i 32

$ cf app static-app

     state      since        cpu    memory        disk
#0   running    2015-11-02   0.0%   6.5M of 16M   33.6M of 64M
#1   starting   2015-11-02   0.0%   0 of  16M     0 of 64M
#2   running    2015-11-02   0.0%   6.9M of 16M   33.5M of 64M
...
#30   running   2015-11-02   0.0%   6.8M of 16M   33.5M of 64M
#31   running   2015-11-02   0.0%   7M of 16M     33.6M of 64M

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DELIVERED

As a CF hero
I want a simple static website
So that I can focus on building my product