{"id":304,"date":"2026-03-22T08:15:00","date_gmt":"2026-03-22T07:15:00","guid":{"rendered":"https:\/\/leblogtech.romain-s.fr\/?p=304"},"modified":"2026-03-22T00:19:57","modified_gmt":"2026-03-21T23:19:57","slug":"docker-comprendre-les-conteneurs","status":"publish","type":"post","link":"https:\/\/leblogtech.romain-s.fr\/index.php\/2026\/03\/22\/docker-comprendre-les-conteneurs\/","title":{"rendered":"Docker : comprendre les conteneurs"},"content":{"rendered":"\n
\n

Cr\u00e9\u00e9 en 2013, Docker<\/strong> s’est rapidement impos\u00e9 comme la r\u00e9f\u00e9rence pour l’empaquetage et la distribution d’applications. Il garantit une ex\u00e9cution fiable et identique de ces applications, quel que soit l’environnement informatique h\u00f4te. Nous allons aborder ce concept dans cet article<\/p>\n\n\n\n

La diff\u00e9rence de Docker<\/strong><\/h2><\/div>\n\n\n\n

Pendant longtemps, la solution pour isoler des applications \u00e9tait la virtualisation classique (VM<\/strong>). Mais Docker propose une approche diff\u00e9rente qui est la conteneurisation<\/strong>.<\/p>\n\n\n\n

\n
<\/path><\/svg><\/span>Machine Virtuelle (VM) :<\/strong> Chaque VM embarque un syst\u00e8me d’exploitation (OS) complet. C’est lourd, cela consomme beaucoup de RAM et de CPU, et le d\u00e9marrage peut prendre plusieurs minutes.<\/span><\/div>\n<\/div><\/div>\n\n\n\n
\"\"<\/figure><\/div>\n\n\n\n
\n
<\/path><\/svg><\/span>Conteneur Docker :<\/strong> Contrairement aux VMs, les conteneurs partagent le noyau (kernel) du syst\u00e8me h\u00f4te. Ils n’isolent que l’application et ses d\u00e9pendances (biblioth\u00e8ques, configurations). R\u00e9sultat : ils sont extr\u00eamement l\u00e9gers, d\u00e9marrent en quelques millisecondes et permettent de faire tourner beaucoup plus d’applications sur un m\u00eame serveur.<\/span><\/div>\n<\/div><\/div>\n\n\n\n
\"\"<\/figure><\/div>\n\n\n\n

Docker, comment \u00e7a marche ?<\/strong><\/h2><\/div>\n\n\n\n

Le fonctionnement de Docker repose sur trois \u00e9l\u00e9ments fondamentaux qui transforment du code en un service pr\u00eat \u00e0 l’emploi qui sont, le Dockerfile<\/strong>, l’Image Docker<\/strong> et le conteneur<\/strong>.<\/p>\n\n\n\n

Le Dockerfile :<\/strong> Il contient toutes les instructions n\u00e9cessaires pour construire l’ environnement (quelle version de Python utiliser, quels fichiers copier, quelles commandes lancer).<\/p>\n\n\n\n

L’Image Docker :<\/strong> C’est le r\u00e9sultat du Dockerfile. C’est un mod\u00e8le immuable et fig\u00e9, construit par \u00ab couches \u00bb successives. Une fois cr\u00e9\u00e9e, une image ne change jamais, ce qui garantit que l’environnement sera strictement le m\u00eame partout.<\/p>\n\n\n\n

Le Conteneur :<\/strong> C’est l’instance vivante de l’image. On peut lancer des dizaines de conteneurs \u00e0 partir d’une seule et m\u00eame image. Pour g\u00e9rer tout cela, le Docker Engine<\/strong> agit comme un chef d’orchestre en arri\u00e8re-plan, traitant les commandes que vous tapez pour cr\u00e9er ou arr\u00eater vos conteneurs.<\/p>\n\n\n\n

Ce que docker cache<\/strong><\/h2><\/div>\n\n\n\n

M\u00eame si Docker simplifie tout, il s’appuie sur des technologies avanc\u00e9es du noyau Linux pour assurer l’isolation dont les namespaces et cgroups.<\/p>\n\n\n\n

\n
<\/path><\/svg><\/span>Namespaces :<\/strong> Ils cr\u00e9ent une bulle isol\u00e9e pour que chaque conteneur croit qu’il est seul au monde (son propre r\u00e9seau, ses propres utilisateurs, ses propres processus).<\/span><\/div>\n\n\n\n
<\/path><\/svg><\/span>Cgroups :<\/strong> Ils permettent de limiter les ressources. On peut dire \u00e0 un conteneur qu’il ne peut pas utiliser plus de 512 Mo de RAM.<\/span><\/div>\n<\/div><\/div>\n\n\n\n

Docker dans le monde du DevOps<\/strong><\/h2><\/div>\n\n\n\n

Dans une d\u00e9marche DevOps, Docker est le cha\u00eenon manquant entre le d\u00e9veloppement et la production. Il permet : <\/p>\n\n\n\n

\n
<\/path><\/svg><\/span>Standardisation :<\/strong> Les d\u00e9veloppeurs cr\u00e9ent le conteneur sur leur poste, et c’est ce m\u00eame conteneur qui sera test\u00e9 puis d\u00e9ploy\u00e9 en production. Les erreurs li\u00e9es aux diff\u00e9rences d’environnement disparaissent.<\/span><\/div>\n\n\n\n
<\/path><\/svg><\/span>Int\u00e9gration Continue (CI\/CD) :<\/strong> Docker facilite l’automatisation. On peut lancer des tests automatiques dans un conteneur jetable pour v\u00e9rifier que le code est correct avant de le d\u00e9ployer.<\/span><\/div>\n\n\n\n
<\/path><\/svg><\/span>Microservices :<\/strong> Docker permet de d\u00e9couper une grosse application complexe en petits services ind\u00e9pendants qui communiquent entre eux, facilitant ainsi la mise \u00e0 jour de chaque partie sans tout casser.<\/span><\/div>\n<\/div><\/div>\n\n\n\n

Conclusion : L’essentiel \u00e0 retenir<\/strong><\/h2><\/div>\n\n\n\n

Docker a transform\u00e9 le d\u00e9veloppement logiciel en rendant les applications portables, l\u00e9g\u00e8res et reproductibles<\/strong>. En utilisant le syst\u00e8me de couches d’images et l’isolation native de Linux, il offre une flexibilit\u00e9 que les machines virtuelles ne peuvent atteindre. C’est aujourd’hui l’outil indispensable pour quiconque souhaite livrer des logiciels de mani\u00e8re moderne et s\u00e9curis\u00e9e.<\/p>\n\n\n\n

Sources et R\u00e9f\u00e9rences Bibliographiques<\/h2><\/div>\n\n\n\n

<\/p>\n\n\n\n

GitLab Blog : Qu\u2019est-ce que Docker ? <\/em><\/strong>Une ressource exhaustive pour distinguer les concepts d’images, de conteneurs et de registres. Elle explique comment Docker Engine agit comme une interface simplifi\u00e9e au-dessus du noyau Linux. lien<\/a><\/p>\n\n\n\n

St\u00e9phane Robert : Ma\u00eetriser la conteneurisation – Le guide complet<\/em> . Il d\u00e9taille les technologies natives Linux, telles que les Namespaces<\/strong> (pour l’isolation) et les Cgroups<\/strong> (pour la limitation des ressources), qui constituent l’ADN de Docker. lien<\/a><\/p>\n\n\n\n

Dyma : Docker et ses conteneurs en profondeur<\/em><\/strong>. lien<\/a><\/p>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"

Cr\u00e9\u00e9 en 2013, Docker s’est rapidement impos\u00e9 comme la r\u00e9f\u00e9rence pour l’empaquetage et la distribution d’applications. Il garantit une ex\u00e9cution […]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_uag_custom_page_level_css":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[11],"tags":[],"class_list":["post-304","post","type-post","status-publish","format-standard","hentry","category-devops"],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false},"uagb_author_info":{"display_name":"romain-s","author_link":"https:\/\/leblogtech.romain-s.fr\/index.php\/author\/romain-s\/"},"uagb_comment_info":0,"uagb_excerpt":"Cr\u00e9\u00e9 en 2013, Docker s’est rapidement impos\u00e9 comme la r\u00e9f\u00e9rence pour l’empaquetage et la distribution d’applications. Il garantit une ex\u00e9cution […]","_links":{"self":[{"href":"https:\/\/leblogtech.romain-s.fr\/index.php\/wp-json\/wp\/v2\/posts\/304","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/leblogtech.romain-s.fr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/leblogtech.romain-s.fr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/leblogtech.romain-s.fr\/index.php\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/leblogtech.romain-s.fr\/index.php\/wp-json\/wp\/v2\/comments?post=304"}],"version-history":[{"count":5,"href":"https:\/\/leblogtech.romain-s.fr\/index.php\/wp-json\/wp\/v2\/posts\/304\/revisions"}],"predecessor-version":[{"id":322,"href":"https:\/\/leblogtech.romain-s.fr\/index.php\/wp-json\/wp\/v2\/posts\/304\/revisions\/322"}],"wp:attachment":[{"href":"https:\/\/leblogtech.romain-s.fr\/index.php\/wp-json\/wp\/v2\/media?parent=304"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/leblogtech.romain-s.fr\/index.php\/wp-json\/wp\/v2\/categories?post=304"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/leblogtech.romain-s.fr\/index.php\/wp-json\/wp\/v2\/tags?post=304"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}