Hello Wolfi

Introductory Live session presented on November 16 about Wolfi, melange, apko, and Chainguard Images.

Transcript

1. Hello, Wolfi!
   An introduction to the Linux (un)distro built for containers
   and Chainguard's open source tools behind it
   chainguard.dev | @erikaheidi
   

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2. What we'll cover today
   ● Wolfi ecosystem overview
   ○ apko, melange, Wolfi, and Chainguard Images
   ● What are distroless images
   ● Migrating to distroless
   ● Demo
   

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3. Ecosystem Overview
   

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5. Wolfi
   ● Tiny Linux Distribution
   ● "Undistro" because it doesn't have stuff that normally goes into a Linux
   distribution (kernel, man pages, a bunch of other packages that don't make
   sense for containers)
   ● Based on apk (the Alpine package manager)
   ● Primarily GLIB-C (but MUSL is on the roadmap)
   ● Packages defined as YAML and built with melange
   

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6. melange
   ● Declarative apk builder tool
   ● Part of the building toolkit behind Wolfi / Chainguard Images
   ● Build pipelines are defined in YAML files
   ● Multi-architecture by default (via QUEMU)
   ● Platform-agnostic builds via Docker + apko image
   

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7. apko
   ● Declarative OCI image builder tool based on apk
   ● Part of the building toolkit behind Wolfi / Chainguard Images
   ● Images are defined in YAML files
   ● Builds are fully reproducible
   ● Automatically generates SBOMs for every image
   ● Platform-agnostic builds via Docker + apko image
   

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8. Chainguard Images
   ● Curated OCI images built with apko and melange
   ● Most based on Wolfi, some still migrating from Alpine as we build more
   package dependencies
   ● Nightly built for several platforms
   ● Zero CVEs goal
   ● High quality SBOMs
   ● Signed with Sigstore
   

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10. Why distroless?
    

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11. The distroless philosophy
    ● Minimalist container images with only what's absolutely necessary to
    build or execute your application
    ● Popular base images are full of software that only makes sense on
    bare-metal
    ● No need for package managers or interactive shells on production
    images
    ● Less dependencies = smaller attack surface, less CVEs
    

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12. The distroless philosophy
    

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13. The distroless philosophy: Chainguard Images
    

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14. Custom distroless images: before / after
    ● php:8.1-cli (Debian-based, official)
    ● Base image total size: 484MB
    ● Total CVEs: 386
    ● minicli/php81 (alpine-based, built with apko)
    ● Base image total size: 48MB
    ● Total CVEs: 0
    

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15. Composing a distroless image
    Steps to build your own distroless image
    

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17. Example apko.yaml file
    contents:
    repositories:
    - https://dl-cdn.alpinelinux.org/alpine/edge/main
    - https://dl-cdn.alpinelinux.org/alpine/edge/community
    packages:
    - alpine-baselayout
    - php81
    - php81-common
    entrypoint:
    command: /usr/bin/php81
    environment:
    PATH: /usr/sbin:/sbin:/usr/bin:/bin
    accounts:
    groups:
    - groupname: nonroot
    gid: 65532
    users:
    - username: nonroot
    uid: 65532
    run-as: 65532
    

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18. Building the image with apko via Docker
    $ docker run --rm -v ${PWD}:/work cgr.dev/chainguard/apko build \
    apko.yaml apko-php:test apko-php.tar
    Testing the image with Docker
    $ docker load < alpine-test.tar
    $ docker run -it alpine-base:test
    

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19. Migration Case Study
    DEMO: Migrating a PHP image to apko /
    distroless
    

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20. App Overview
    ● GitHub Action that runs
    on schedule
    ● Using an image based on
    the official php:7.4-cli
    ○ Size: 589MB
    ○ CVEs (Trivy): 331
    

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21. Migration step 1: collecting dependencies
    FROM php:7.4-cli
    ARG user=dynacover
    ARG uid=1000
    RUN apt-get update && apt-get install -y git curl libonig-dev libxml2-dev libfreetype6-dev
    libjpeg62-turbo-dev libpng-dev zip unzip
    RUN apt-get clean && rm -rf /var/lib/apt/lists/*
    RUN docker-php-ext-configure gd --with-freetype --with-jpeg && \
    docker-php-ext-install pdo_mysql mbstring exif pcntl bcmath gd
    COPY --from=composer:latest /usr/bin/composer /usr/bin/composer
    RUN useradd -G sudo,root -u $uid -d /home/$user $user
    RUN mkdir -p /home/$user/.composer && \
    chown -R $user:$user /home/$user
    USER $user
    RUN mkdir -p /home/$user/dynacover
    COPY . /home/$user/dynacover/
    WORKDIR /home/$user/dynacover
    RUN composer install
    …
    

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22. Migration step 2: finding appropriate apks
    

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24. Dynacover base image: before / after
    ● Based on php:7.4-cli
    ● Base image total size: 589MB
    ● Total CVEs: 331
    ● Distroless based on Alpine
    ● Base image total size: 48MB
    ● Total CVEs: 0
    

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25. Resources to Learn More
    ● Chainguard Academy
    ● Wolfi documentation
    ● melange + apko tutorial on Chainguard Academy
    ● Chainguard Images documentation
    ● apko on GitHub
    ● Troubleshooting apko builds
    

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26. Questions?
    

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27. Thank You!
    chainguard.dev | edu.chainguard.dev
    @chainguard_dev
    chainguard-dev
    

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