{"id":1244,"date":"2024-07-23T12:16:07","date_gmt":"2024-07-23T12:16:07","guid":{"rendered":"https:\/\/dockerpros.com\/?post_type=glossary&p=1244"},"modified":"2024-07-23T12:21:35","modified_gmt":"2024-07-23T12:21:35","slug":"docker-build-cache","status":"publish","type":"glossary","link":"https:\/\/dockerpros.com\/fr\/wiki\/docker-build-cache\/","title":{"rendered":"Cache de construction Docker"},"content":{"rendered":"

Understanding Docker Build Cache: An Advanced Guide<\/h1>\n

Le Docker Build Cache est un m\u00e9canisme qui am\u00e9liore l'efficacit\u00e9 de la construction d'images 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> Le processus de construction en tirant parti de la mise en cache des couches interm\u00e9diaires d'images, qui peuvent \u00eatre r\u00e9utilis\u00e9es lors des constructions ult\u00e9rieures. Cela permet aux d\u00e9veloppeurs d'\u00e9viter les t\u00e2ches redondantes, acc\u00e9l\u00e9rant consid\u00e9rablement le processus de construction lorsque des modifications sont apport\u00e9es. En utilisant intelligemment la mise en cache, Docker aide \u00e0 optimiser l'utilisation des ressources et la gestion du temps, ce qui en fait une fonctionnalit\u00e9 essentielle pour les d\u00e9veloppeurs travaillant avec des applications conteneuris\u00e9es.<\/p>\n

The Architecture of Docker Build Cache<\/h2>\n

To grasp the nuances of Docker Build Cache, it’s important to first understand how Docker images are constructed. A 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> consists of a series of layers, each representing a change made to the filesystem. These layers are created as a result of the commands specified 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>. The layers are built in a specific order, and Docker maintains a cache of these layers to optimize future builds.<\/p>\n

Dockerfile and Layer Creation<\/h3>\n

When a 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 processed, each instruction (like 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>, 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>, etc.) g\u00e9n\u00e8re une nouvelle couche. Les couches sont immuables, ce qui signifie qu'une fois cr\u00e9\u00e9es, elles ne peuvent \u00eatre modifi\u00e9es. Chaque couche est identifi\u00e9e par un hachage unique bas\u00e9 sur son contenu. Si le contenu d'une couche reste inchang\u00e9, Docker peut r\u00e9utiliser la version en cache de cette couche pour les constructions suivantes.<\/p>\n

Comportement du cache<\/h3>\n

Le m\u00e9canisme de cache de Docker utilise un algorithme sp\u00e9cifique pour d\u00e9terminer s'il faut utiliser une couche mise en cache ou en construire une nouvelle. Ce m\u00e9canisme de cache suit le principe de \"l'invalidation du cache\". Si une partie de la commande d'une couche change, cette couche et toutes les couches suivantes sont reconstruites. Ce comportement permet \u00e0 Docker d'\u00eatre \u00e0 la fois efficace et pr\u00e9visible.<\/p>\n

Types of Build Cache<\/h2>\n

Docker supports different types of build caches that developers can utilize to enhance their build processes:<\/p>\n

Cache de build local<\/h3>\n

Le cache de construction local est stock\u00e9 sur la machine du d\u00e9veloppeur. Il comprend toutes les couches cr\u00e9\u00e9es lors de la construction des images sur cette machine. Ce cache est cr\u00e9\u00e9 automatiquement au fur et \u00e0 mesure que les couches sont construites et peut \u00eatre r\u00e9utilis\u00e9 lors de constructions futures. Cependant, il est sp\u00e9cifique \u00e0 l'environnement local, ce qui signifie que si un d\u00e9veloppeur change de machine ou d'environnement, il n'aura pas acc\u00e8s \u00e0 ce cache.<\/p>\n

2. Remote Build Cache<\/h3>\n

With the introduction of BuildKit, Docker supports remote caching capabilities. This allows developers to push their build cache to remote repositories. Remote caching can significantly speed up builds in Continuous Integration\/Continuous Deployment (CI\/CD) pipelines by allowing multiple developers or CI\/CD agents to share cache layers.<\/p>\n

3. Exportation\/Importation de cache<\/h3>\n

Docker also provides the ability to export and import build cache. Using the --cache-depuis<\/code> option, developers can specify existing images or cache stored in a remote repository<\/a><\/span>A repository is a centralized location where data, code, or documents are stored, managed, and maintained. It facilitates version control, collaboration, and efficient resource sharing among users. More \u00bb<\/a><\/span><\/span><\/span><\/span><\/span><\/span><\/span> \u00e0 utiliser comme source de cache pour la construction. Cette fonctionnalit\u00e9 permet une plus grande flexibilit\u00e9 dans la gestion des environnements de construction et acc\u00e9l\u00e8re les constructions en tirant parti des caches existants provenant d'autres sources.<\/p>\n

Optimizing the Build Cache Usage<\/h2>\n

To effectively utilize Docker Build Cache, developers can adopt several best practices that will help optimize the way caches are 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.<\/p>\n

1. Organisez intelligemment les instructions du Dockerfile<\/h3>\n

The order of commands in a 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> can significantly impact cache efficiency. Instructions that are less likely to change should be placed higher 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>. For instance, installing dependencies should come before adding application code. This way, if only the application code changes, the dependency layer can still be reused from the cache.<\/p>\n

# Efficiently ordering 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> instructions\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\n# Install dependencies\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> package*.json .\/\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> npm install\n\n# Copier<\/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> application code\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> . .\n\n# Build the application\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> npm 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> construire<\/code><\/pre>\n
Dans l'exemple ci-dessus, si seul le code de l'application change, le npm install<\/code> L'\u00e9tape peut \u00eatre mise en cache, ce qui permet un gain de temps.<\/p>\n
2. Utilisez des builds multi-\u00e9tapes<\/h3>\n
Multi-stage builds allow developers to create smaller final images by using multiple FROM<\/code> statements in a 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>. Each stage can utilize cached layers from previous stages, reducing 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 build time. <\/p>\n
# First stage: build the application\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 en tant que constructeur\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> package*.json .\/\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> npm install\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> . .\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> npm 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> build\n\n# Second stage: create the final image\nFROM nginx:alpine\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> --from=builder \/app\/build \/usr\/share\/nginx\/html<\/code><\/pre>\n
With this approach, if the application code changes, only the build stage needs to be rebuilt, while 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> can still benefit from the cached layers of the 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>.<\/p>\n
3. Utilize BuildKit<\/h3>\n
Docker BuildKit introduit des fonctionnalit\u00e9s de mise en cache et d'ex\u00e9cution parall\u00e8le plus avanc\u00e9es. Pour activer BuildKit, d\u00e9finissez la variable d'environnement DOCKER_BUILDKIT=1<\/code>. With BuildKit, developers can take advantage of features like cache import\/export, automatic layer squashing, and build secrets.<\/p>\n
4. \u00c9vitez les couches inutiles<\/h3>\n
Each command 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> creates a new layer. By minimizing the number of commands, you can reduce the total layer count, which can improve cache performance. Grouping commands using &&<\/code> can help achieve this.<\/p>\n
# Instead of multiple 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> commands\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  package1 \n  package2 \n  package3<\/code><\/pre>\n
La r\u00e9duction du nombre de couches minimise la quantit\u00e9 de donn\u00e9es qui doivent \u00eatre mises en cache et acc\u00e9l\u00e8re le processus de construction.<\/p>\n
5. Utilisation --no-cache<\/code> Strategically<\/h3>\n
Bien que les caches soient utiles, il y a des moments o\u00f9 vous pourriez vouloir forcer une reconstruction. En utilisant le --no-cache<\/code> option when building an 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> ensures that no cached layers are used. This can be helpful for debugging or ensuring that you have the latest versions of dependencies.<\/p>\n
Diagnostic des probl\u00e8mes de cache de construction\n\nBuild cache issues can be tricky to diagnose. This page describes some common issues and how to resolve them.\n\nProbl\u00e8mes de cache de construction peuvent \u00eatre difficiles \u00e0 diagnostiquer. Cette page d\u00e9crit certains probl\u00e8mes courants et comment les r\u00e9soudre.\n\nBuild cache is not being used<\/h2>\n
Despite best efforts, issues with the build cache may arise. Diagnosing these issues can be crucial for maintaining efficient build processes.<\/p>\n
1. \u00c9checs de cache de construction<\/h3>\n
Un probl\u00e8me courant est de rencontrer des erreurs de cache, o\u00f9 Docker d\u00e9cide de reconstruire des couches que vous vous attendez \u00e0 voir mises en cache. Cela se produit g\u00e9n\u00e9ralement lorsque :<\/p>\n