{"id":1330,"date":"2024-07-23T12:21:24","date_gmt":"2024-07-23T12:21:24","guid":{"rendered":"https:\/\/dockerpros.com\/?post_type=glossary&p=1330"},"modified":"2024-07-23T12:23:38","modified_gmt":"2024-07-23T12:23:38","slug":"dockerfile-squash","status":"publish","type":"glossary","link":"https:\/\/dockerpros.com\/fr\/wiki\/dockerfile-squash\/","title":{"rendered":"Dockerfile \u2013squash"},"content":{"rendered":"

Understanding Dockerfile \u2013squash: An Advanced Guide<\/h1>\n

Lors de la construction d'images Docker, chaque commande dans un Dockerfile... Dockerfile<\/a><\/span>A Dockerfile is a script containing a series of instructions to automate the creation of Docker images. It specifies the base image, application dependencies, and configuration, facilitating consistent deployment across environments. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> g\u00e9n\u00e8re une nouvelle couche dans le r\u00e9sultat image<\/a><\/span>Une image est une repr\u00e9sentation visuelle d'un objet ou d'une sc\u00e8ne, g\u00e9n\u00e9ralement compos\u00e9e de pixels dans les formats num\u00e9riques. Elle peut transmettre des informations, susciter des \u00e9motions et faciliter la communication \u00e0 travers diff\u00e9rents m\u00e9dias. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span>. Le --squash<\/code> option in Docker provides the ability to squash these layers into a single layer, which can help reduce the overall image<\/a><\/span>Une image est une repr\u00e9sentation visuelle d'un objet ou d'une sc\u00e8ne, g\u00e9n\u00e9ralement compos\u00e9e de pixels dans les formats num\u00e9riques. Elle peut transmettre des informations, susciter des \u00e9motions et faciliter la communication \u00e0 travers diff\u00e9rents m\u00e9dias. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> size and improve performance. This feature is particularly useful in scenarios where the intermediate layers created during the build process are not needed for the final image<\/a><\/span>Une image est une repr\u00e9sentation visuelle d'un objet ou d'une sc\u00e8ne, g\u00e9n\u00e9ralement compos\u00e9e de pixels dans les formats num\u00e9riques. Elle peut transmettre des informations, susciter des \u00e9motions et faciliter la communication \u00e0 travers diff\u00e9rents m\u00e9dias. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span>, allowing for cleaner and more efficient deployment.<\/p>\n

The Importance of Docker Layers<\/h2>\n

To appreciate the significance of the --squash<\/code> option, it\u2019s essential to first understand Docker\u2019s layering architecture. Docker images are composed of a series of layers, each representing a set of filesystem changes. Every command in a Dockerfile\u2014such as RUN<\/a><\/span>\"RUN\" refers to a command in various programming languages and operating systems to execute a specified program or script. It initiates processes, providing a controlled environment for task execution. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span><\/code>, COPIE<\/a><\/span>COPY is a command in computer programming and data management that facilitates the duplication of files or data from one location to another, ensuring data integrity and accessibility. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span><\/code>, and ADD<\/a><\/span>La commande ADD dans Docker est une instruction utilis\u00e9e dans les Dockerfiles pour copier des fichiers et des r\u00e9pertoires depuis une machine h\u00f4te vers une image Docker pendant le processus de construction. Elle facilite non seulement le transfert de fichiers locaux, mais offre \u00e9galement des fonctionnalit\u00e9s suppl\u00e9mentaires, telles que l'extraction automatique de fichiers compress\u00e9s et le t\u00e9l\u00e9chargement de fichiers distants via HTTP ou HTTPS. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span><\/code>\u2014 cr\u00e9e une nouvelle couche au-dessus de la pr\u00e9c\u00e9dente. Cette conception pr\u00e9sente plusieurs avantages :<\/p>\n

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  1. Efficiency<\/strong>: Le calque permet \u00e0 Docker de r\u00e9utiliser les calques inchang\u00e9s entre les images, r\u00e9duisant ainsi la redondance et acc\u00e9l\u00e9rant les temps de construction.<\/li>\n
  2. Caching<\/strong>Docker met en cache les couches pour des reconstructions plus rapides. Si une couche n'a pas chang\u00e9, Docker n'a pas besoin de la r\u00e9g\u00e9n\u00e9rer.<\/li>\n
  3. Incremental Updates<\/strong>Seules les couches qui ont chang\u00e9 doivent \u00eatre reconstruites, ce qui permet des mises \u00e0 jour plus efficaces.<\/li>\n<\/ol>\n

    However, while layers are beneficial, they can also lead to larger image<\/a><\/span>Une image est une repr\u00e9sentation visuelle d'un objet ou d'une sc\u00e8ne, g\u00e9n\u00e9ralement compos\u00e9e de pixels dans les formats num\u00e9riques. Elle peut transmettre des informations, susciter des \u00e9motions et faciliter la communication \u00e0 travers diff\u00e9rents m\u00e9dias. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> sizes. Each layer contains not only the changes made by its corresponding command but also metadata. For large images with many layers, the size can become unwieldy, leading to longer download times and increased storage costs. This is where the --squash<\/code> option becomes relevant.<\/p>\n

    Que fait --squash<\/code> Do?<\/h2>\n

    The --squash<\/code> option was introduced as an experimental feature in Docker 1.13 and is intended to be used during the image<\/a><\/span>Une image est une repr\u00e9sentation visuelle d'un objet ou d'une sc\u00e8ne, g\u00e9n\u00e9ralement compos\u00e9e de pixels dans les formats num\u00e9riques. Elle peut transmettre des informations, susciter des \u00e9motions et faciliter la communication \u00e0 travers diff\u00e9rents m\u00e9dias. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> build process. When you invoke docker build<\/code> with the --squash<\/code> flag, Docker combines all of the layers created during the build into a single layer. This means that the final image<\/a><\/span>Une image est une repr\u00e9sentation visuelle d'un objet ou d'une sc\u00e8ne, g\u00e9n\u00e9ralement compos\u00e9e de pixels dans les formats num\u00e9riques. Elle peut transmettre des informations, susciter des \u00e9motions et faciliter la communication \u00e0 travers diff\u00e9rents m\u00e9dias. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> will consist of only one layer containing all of the modifications made via the commands in the Dockerfile<\/a><\/span>A Dockerfile is a script containing a series of instructions to automate the creation of Docker images. It specifies the base image, application dependencies, and configuration, facilitating consistent deployment across environments. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span>.<\/p>\n

    Syntax<\/h3>\n
    docker build --squash -t : .<\/code><\/pre>\n
    Exemple<\/h3>\n
    Consider the following simple Dockerfile<\/a><\/span>A Dockerfile is a script containing a series of instructions to automate the creation of Docker images. It specifies the base image, application dependencies, and configuration, facilitating consistent deployment across environments. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span>:<\/p>\n
    FROM ubuntu:20.04\n\nRUN<\/a><\/span>\"RUN\" refers to a command in various programming languages and operating systems to execute a specified program or script. It initiates processes, providing a controlled environment for task execution. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> apt-get update && apt-get install -y \n    curl \n    vim \n    git\n\nCOPIE<\/a><\/span>COPY is a command in computer programming and data management that facilitates the duplication of files or data from one location to another, ensuring data integrity and accessibility. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> . \/app\n\nRUN<\/a><\/span>\"RUN\" refers to a command in various programming languages and operating systems to execute a specified program or script. It initiates processes, providing a controlled environment for task execution. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> make \/app<\/code><\/pre>\n
    If we build this image<\/a><\/span>Une image est une repr\u00e9sentation visuelle d'un objet ou d'une sc\u00e8ne, g\u00e9n\u00e9ralement compos\u00e9e de pixels dans les formats num\u00e9riques. Elle peut transmettre des informations, susciter des \u00e9motions et faciliter la communication \u00e0 travers diff\u00e9rents m\u00e9dias. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> without squashing, we will have multiple layers, including:<\/p>\n