{"id":1310,"date":"2024-07-23T12:20:15","date_gmt":"2024-07-23T12:20:15","guid":{"rendered":"https:\/\/dockerpros.com\/?post_type=glossary&p=1310"},"modified":"2024-07-23T12:23:05","modified_gmt":"2024-07-23T12:23:05","slug":"dockerfile-onbuild","status":"publish","type":"glossary","link":"https:\/\/dockerpros.com\/fr\/wiki\/dockerfile-onbuild\/","title":{"rendered":"Dockerfile ONBUILD"},"content":{"rendered":"

Comprendre Dockerfile ONBUILD : Une plong\u00e9e approfondie dans les techniques avanc\u00e9es de Dockerfile\n\nIntroduction\n\nDockerfile est un outil puissant pour cr\u00e9er des images Docker personnalis\u00e9es. Il permet aux d\u00e9veloppeurs de d\u00e9finir les \u00e9tapes n\u00e9cessaires pour construire une image, y compris l'installation de d\u00e9pendances, la configuration de l'environnement et la d\u00e9finition des commandes \u00e0 ex\u00e9cuter lors du d\u00e9marrage du conteneur. Bien que la plupart des d\u00e9veloppeurs soient familiers avec les instructions de base de Dockerfile telles que FROM, RUN et CMD, il existe une instruction moins connue mais tout aussi importante : ONBUILD.\n\nQu'est-ce que ONBUILD ?\n\nONBUILD est une instruction Dockerfile sp\u00e9ciale qui vous permet de d\u00e9finir des instructions qui seront ex\u00e9cut\u00e9es plus tard, lorsque l'image est utilis\u00e9e comme base pour une autre image. En d'autres termes, ONBUILD vous permet de cr\u00e9er des images de base qui peuvent \u00eatre \u00e9tendues par d'autres images, avec des instructions sp\u00e9cifiques qui seront automatiquement ex\u00e9cut\u00e9es lors du processus de construction de l'image enfant.\n\nPourquoi utiliser ONBUILD ?\n\nONBUILD est particuli\u00e8rement utile dans les sc\u00e9narios o\u00f9 vous souhaitez cr\u00e9er une image de base qui peut \u00eatre facilement \u00e9tendue par d'autres images. Par exemple, supposons que vous ayez une application web qui n\u00e9cessite une configuration sp\u00e9cifique pour chaque d\u00e9ploiement. Au lieu de dupliquer la configuration dans chaque Dockerfile, vous pouvez cr\u00e9er une image de base avec la configuration commune et utiliser ONBUILD pour appliquer automatiquement la configuration sp\u00e9cifique lors de la construction de l'image enfant.\n\nComment utiliser ONBUILD\n\nL'utilisation de ONBUILD est simple. Vous ajoutez simplement l'instruction ONBUILD suivie de l'instruction que vous souhaitez ex\u00e9cuter plus tard. Par exemple :\n\n```dockerfile\nFROM ubuntu:latest\nONBUILD RUN apt-get update && apt-get install -y nginx\n```\n\nDans cet exemple, l'instruction ONBUILD sp\u00e9cifie qu'au moment o\u00f9 une image est construite en utilisant cette image comme base, la commande RUN sera automatiquement ex\u00e9cut\u00e9e. Cela signifie que chaque image enfant construite \u00e0 partir de cette image de base aura nginx install\u00e9.\n\nLimitations et meilleures pratiques\n\nBien que ONBUILD soit un outil puissant, il est important de l'utiliser avec pr\u00e9caution. Voici quelques limitations et meilleures pratiques \u00e0 garder \u00e0 l'esprit :\n\n1. Les instructions ONBUILD ne peuvent \u00eatre utilis\u00e9es qu'avec un sous-ensemble d'instructions Dockerfile. Les instructions suivantes sont prises en charge : RUN, COPY, ADD, WORKDIR, ENV, EXPOSE, VOLUME et USER.\n\n2. Les instructions ONBUILD sont ex\u00e9cut\u00e9es dans l'ordre o\u00f9 elles apparaissent dans le Dockerfile. Assurez-vous de les organiser logiquement pour \u00e9viter tout comportement inattendu.\n\n3. Les instructions ONBUILD ne sont pas h\u00e9rit\u00e9es par les images construites \u00e0 partir d'images enfants. Si vous souhaitez que les instructions ONBUILD soient appliqu\u00e9es \u00e0 plusieurs niveaux d'images, vous devez les inclure dans chaque image de base.\n\n4. Soyez prudent lorsque vous utilisez ONBUILD avec des instructions qui modifient le syst\u00e8me de fichiers, comme RUN ou COPY. Ces instructions peuvent avoir des cons\u00e9quences involontaires si elles sont ex\u00e9cut\u00e9es dans le contexte de l'image enfant.\n\nConclusion\n\nDockerfile ONBUILD est une fonctionnalit\u00e9 puissante qui permet aux d\u00e9veloppeurs de cr\u00e9er des images de base qui peuvent \u00eatre facilement \u00e9tendues par d'autres images. En utilisant ONBUILD, vous pouvez automatiser l'ex\u00e9cution d'instructions sp\u00e9cifiques lors de la construction d'images enfants, ce qui facilite la maintenance et la coh\u00e9rence de vos images Docker. Cependant, il est important d'utiliser ONBUILD avec pr\u00e9caution et de suivre les meilleures pratiques pour \u00e9viter tout comportement inattendu.<\/h1>\n

Introduction<\/h2>\n

Dans le domaine de la conteneurisation, Docker s'est impos\u00e9 comme le standard de facto pour empaqueter des applications et leurs d\u00e9pendances dans des environnements isol\u00e9s appel\u00e9s conteneurs. 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> est un script qui contient une s\u00e9rie d'instructions sur la fa\u00e7on de construire un Docker 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>. Parmi ces instructions, ONBUILD<\/code> stands out as a unique directive that allows a parent 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> to specify actions that should be executed when 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> is used as a base for a child 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>. This article will delve into the intricacies of the ONBUILD<\/code> instruction, ses cas d'utilisation, ses avantages et ses pi\u00e8ges potentiels, le tout visant \u00e0 fournir une vue d'ensemble compl\u00e8te de cette fonctionnalit\u00e9 avanc\u00e9e de Docker.<\/p>\n

Qu'est-ce que l'instruction ONBUILD ?<\/h2>\n

The ONBUILD<\/code> instruction dans un 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> is used to trigger actions in a child 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> that is built from a parent 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>. When a parent 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> with an ONBUILD<\/code> instruction is used as the base for a new Docker 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>, the specified instructions will automatically be executed in the context of the child 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>. This allows for a level of abstraction and reuse that can streamline the Docker 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> creation process, especially in multi-tiered applications.<\/p>\n

Syntax of ONBUILD<\/h3>\n

La syntaxe pour utiliser ONBUILD<\/code> is straightforward. You simply prefix the command you want to be executed with ONBUILD<\/code>. Voici un exemple :<\/p>\n

Dockerfile parent #\nFROM n\u0153ud<\/a><\/span>Node, or Node.js, is a JavaScript runtime built on Chrome's V8 engine, enabling server-side scripting. It allows developers to build scalable network applications using asynchronous, event-driven architecture. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span>ONBUILD 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> npm install<\/code><\/pre>\n
In this example, when a new 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> is built using this parent 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>, it will automatically execute 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> npm install<\/code> as part of the build process.<\/p>\n
Les cas d'utilisation pour ONBUILD<\/h2>\n
1. Simplifying Child Image Creation<\/h3>\n
One of the primary advantages of using ONBUILD<\/code> is the ability to simplify the creation of child images. For example, if you have a standard set of dependencies or configurations that need to be set up across multiple applications, you can encapsulate those in a parent 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> with ONBUILD<\/code> directives. This way, the child images inherit the necessary setup without duplicating code.<\/p>\n
Sc\u00e9nario d'exemple<\/h4>\n
Consider a scenario where multiple applications require the same base setup for a web server. By creating a parent 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> that installs common packages and configurations through ONBUILD<\/code>, les d\u00e9veloppeurs peuvent concentrer leurs efforts sur les aspects uniques de leurs applications sp\u00e9cifiques.<\/p>\n
2. Enforcing Best Practices<\/h3>\n
En utilisant ONBUILD<\/code> can also help enforce best practices across teams or projects. For example, you might want to ensure that every child 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> performs specific security or performance optimizations. By embedding these instructions in a parent 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>, you can maintain consistency and reduce the likelihood of errors.<\/p>\n
Modularisation des images Docker<\/h3>\n
In a microservices architecture, where different services might share common functionality, ONBUILD<\/code> allows for modular Docker 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> design. Each service<\/a><\/span>Le service fait r\u00e9f\u00e9rence \u00e0 l'acte de fournir une assistance ou un soutien pour r\u00e9pondre \u00e0 des besoins ou des exigences sp\u00e9cifiques. Dans divers domaines, il englobe le service client, le support technique et les services professionnels, en mettant l'accent sur l'efficacit\u00e9 et la satisfaction de l'utilisateur. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> can inherit from a common base 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> that contains shared logic or dependencies, leading to cleaner and more maintainable codebases.<\/p>\n
Bonnes pratiques pour l'utilisation de ONBUILD\n\nLes instructions ONBUILD sont utiles dans les images Docker qui servent de base \u00e0 d'autres images, comme le montre l'exemple de l'image parente d'une application Ruby. Ces images de base ex\u00e9cutent la configuration de l'environnement de l'application, puis l'image enfant utilise cette configuration pour ex\u00e9cuter son code.\n\n\u00c9tant donn\u00e9 que l'instruction ONBUILD est ex\u00e9cut\u00e9e avant toute instruction dans un enfant, l'instruction doit \u00eatre plac\u00e9e aussi t\u00f4t que possible dans le Dockerfile. Il est recommand\u00e9 de placer l'instruction ONBUILD avant toute instruction qui pourrait \u00e9chouer, comme FROM, MAINTAINER et RUN.\n\nPar exemple, vous devriez passer les arguments \u00e0 ONBUILD qui ne seront pas disponibles plus tard, comme vous pouvez le voir dans cet exemple Dockerfile :\n\n```dockerfile\nFROM debian\nRUN apt-get update && apt-get install -y x11vnc xvfb firefox\nRUN mkdir ~\/.vnc\n# Setup password\nRUN x11vnc -storepasswd 1234 ~\/.vnc\/passwd\nEXPOSE 5900\nENV DISPLAY :1\nONBUILD RUN apt-get update && apt-get install -y firefox\nENTRYPOINT [\"x11vnc\", \"-forever\", \"-usepw\", \"-create\"]\n```\n\n\u00c9vitez d'utiliser l'instruction ONBUILD avec des instructions ADD et COPY. Si l'image de base n'existe pas, l'image enfant \u00e9chouera lors de l'ex\u00e9cution de l'instruction ADD ou COPY. Il n'y a pas de validation de la pr\u00e9sence de fichiers locaux \u00e0 l'\u00e9tape ONBUILD.<\/h2>\n
While ONBUILD<\/code> peut apporter des avantages consid\u00e9rables, il est essentiel de l'utiliser avec discernement. Voici quelques bonnes pratiques \u00e0 garder \u00e0 l'esprit :<\/p>\n
1. Documentez clairement les instructions ONBUILD<\/h3>\n
Depuis ONBUILD<\/code> instructions will execute in a child 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>, it’s crucial to document what these instructions do and what assumptions they make. Failure to do so can lead to confusion, especially for new developers or teams that may not be aware of the inherited behaviors.<\/p>\n
2. Utilisez ONBUILD avec parcimonie<\/h3>\n
Overuse of ONBUILD<\/code> can lead to complex and hard-to-debug build processes. Aim to use it only when there are clear benefits to abstracting away repeated logic. If the logic is unique to a specific application or microservice, it may be better to define it directly in the child 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>.<\/p>\n
3. Test Parent Images Thoroughly<\/h3>\n
Before deploying a parent 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> with ONBUILD<\/code> instructions, make sure to test it thoroughly. Since the behavior of the child images will depend on these instructions, any issues in the parent 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> could propagate to all child images, causing widespread issues.<\/p>\n
4. Versionnage des images parentes<\/h3>\n
As with any 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> in Docker, consider versioning your parent images. When making changes to an ONBUILD<\/code> Si vous modifiez une instruction, vous pouvez involontairement modifier le comportement des images enfants existantes. Une gestion appropri\u00e9e de la version peut aider \u00e0 g\u00e9rer ces changements et \u00e9viter de casser les applications existantes.<\/p>\n
Limitations of ONBUILD<\/h2>\n
While ONBUILD<\/code> Bien qu'elle puisse \u00eatre un outil puissant, il est essentiel d'\u00eatre conscient de ses limites.<\/p>\n
1. Implicit Behavior<\/h3>\n
One of the most significant downsides of ONBUILD<\/code> is its implicit behavior. Developers using a child 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> may not immediately realize that certain instructions are being executed without their explicit inclusion 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>. This can lead to unexpected results, especially if the ONBUILD<\/code> Les instructions impliquent des op\u00e9rations complexes ou des d\u00e9pendances.<\/p>\n
2. Reduced Transparency<\/h3>\n
Lors de l'utilisation de ONBUILD<\/code>, it can be challenging to understand the complete build process just by looking at the child image\u2019s 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>. This lack of transparency can complicate troubleshooting efforts when issues arise.<\/p>\n
3. Compatibility Issues<\/h3>\n
Changes to the ONBUILD<\/code> instructions in a parent 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> can lead to compatibility issues in child images. This is particularly true if the child images were built against an older version of the parent. Careful management of 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> versions is necessary to mitigate this risk.<\/p>\n
Practical Examples of Using ONBUILD<\/h2>\n
Pour illustrer ce concept plus clairement, explorons quelques exemples pratiques de la fa\u00e7on dont ONBUILD<\/code> peut \u00eatre utilis\u00e9 efficacement.<\/p>\n
Exemple 1 : Configuration de l'application Python<\/h3>\n
Imagine you are developing a set of microservices in Python, and you want each service<\/a><\/span>Le service fait r\u00e9f\u00e9rence \u00e0 l'acte de fournir une assistance ou un soutien pour r\u00e9pondre \u00e0 des besoins ou des exigences sp\u00e9cifiques. Dans divers domaines, il englobe le service client, le support technique et les services professionnels, en mettant l'accent sur l'efficacit\u00e9 et la satisfaction de l'utilisateur. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> to install common dependencies. You could create a parent 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> comme \u00e7a<\/p>\n
# Parent 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> for Python apps\nFROM python:3.9\n\nONBUILD 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> requirements.txt \/app\/\nONBUILD 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> pip install -r \/app\/requirements.txt\nONBUILD 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> . \/app\/<\/code><\/pre>\n
When a child 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> is created from this parent, the specified ONBUILD<\/code> instructions will automatically 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> the requirements.txt<\/code> and install dependencies, ensuring that all services have the necessary packages.<\/p>\n
Exemple 2 : Initialisation d'une application Node.js<\/h3>\n
Pour Node<\/a><\/span>Node, or Node.js, is a JavaScript runtime built on Chrome's V8 engine, enabling server-side scripting. It allows developers to build scalable network applications using asynchronous, event-driven architecture. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span>.js applications, you might want a similar pattern. Here is how that might look:<\/p>\n
# Parent 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> for Node<\/a><\/span>Node, or Node.js, is a JavaScript runtime built on Chrome's V8 engine, enabling server-side scripting. It allows developers to build scalable network applications using asynchronous, event-driven architecture. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span>.js apps\nFROM n\u0153ud<\/a><\/span>Node, or Node.js, is a JavaScript runtime built on Chrome's V8 engine, enabling server-side scripting. It allows developers to build scalable network applications using asynchronous, event-driven architecture. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span>:14\n\nONBUILD WORKDIR<\/a><\/span>L'instruction `WORKDIR` dans le Dockerfile d\u00e9finit le r\u00e9pertoire de travail pour les instructions suivantes. Elle simplifie la gestion des chemins, car tous les chemins relatifs seront r\u00e9solus \u00e0 partir de ce r\u00e9pertoire, am\u00e9liorant ainsi la clart\u00e9 de la construction. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span> \/usr\/src\/app\nONBUILD 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> package*.json .\/\nONBUILD 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> npm install\nONBUILD 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><\/pre>\n
With this setup, any Node<\/a><\/span>Node, or Node.js, is a JavaScript runtime built on Chrome's V8 engine, enabling server-side scripting. It allows developers to build scalable network applications using asynchronous, event-driven architecture. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span>.js application that uses this parent 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 automatically set up its working directory, 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> its package files, and install its npm dependencies.<\/p>\n
Conclusion<\/h2>\n
The ONBUILD<\/code> instruction in Dockerfiles is a powerful feature that can enhance the usability and maintainability of Docker images. By allowing parent images to dictate behaviors for child images, it promotes code reuse and can help enforce best practices across teams and projects.<\/p>\n
Cependant, avec un grand pouvoir vient une grande responsabilit\u00e9. Il est crucial d'utiliser ONBUILD<\/code> judiciously, ensuring that it does not lead to confusion or compatibility issues down the line. Documenting the behavior of ONBUILD<\/code> Les instructions, les tests approfondis et la gestion prudente des versions sont des pratiques essentielles pour maintenir un \u00e9cosyst\u00e8me Docker sain et efficace.<\/p>\n
By understanding and applying the knowledge of ONBUILD<\/code>, Docker users can streamline their image-building processes and foster a more modular and maintainable approach to containerized applications.<\/p>","protected":false},"excerpt":{"rendered":"
L'instruction `ONBUILD` dans un 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> allows you to specify actions that should be executed when 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> est utilis\u00e9 comme base pour une autre construction. Cette fonctionnalit\u00e9 est utile pour cr\u00e9er des images r\u00e9utilisables avec des comportements pr\u00e9d\u00e9finis.<\/p>","protected":false},"author":1,"featured_media":1937,"parent":0,"template":"","glossary-cat":[],"class_list":["post-1310","glossary","type-glossary","status-publish","has-post-thumbnail","hentry"],"yoast_head":"\nDockerfile ONBUILD - Dockerpros<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/dockerpros.com\/fr\/wiki\/dockerfile-onbuild\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Dockerfile ONBUILD - Dockerpros\" \/>\n<meta property=\"og:description\" content=\"The `ONBUILD` instruction in a Dockerfile allows you to specify actions that should be executed when the image is used as a base for another build. 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