docker --versionDocker version 29.9.0, build f415da8
Découvrir les conteneurs avec Docker
Donner le goût des conteneurs en pratiquant :
run, ps, stop, rmCe TP n’est pas un TP de production. Il vise à construire une intuition correcte des conteneurs.
docker --versionDocker version 29.9.0, build f415da8
Si l’installation de Docker localement est difficile, vous pouvez utiliser un environnement en ligne tel que Play with Docker ou Katacoda.
Les commandes présentées dans ce TP utilisent les formes longues des options pour plus de clarté. Formes longues ↔︎ courtes
-d-p-v-i-t-eCréer un dossier de travail et s’y positionner ($TP_DIR="~/tp0-containers-101") :
Nettoyage optionnel des restes d’exécutions précédentes :
docker rm --force tp0-nginx tp0-app 2>/dev/null || true
docker network rm tp0-net 2>/dev/null || true
docker image rm tp0-app:0.1 2>/dev/null || trueVoir un conteneur en cours d’exécution.
La commande suivante lance un conteneur nginx (serveur web) en arrière-plan, nommé tp0-nginx, exposant le port 80 du conteneur sur le port 8080 de l’hôte :
docker rm -f tp0-nginx >/dev/null 2>&1 || true
docker run --label ebpro-render=true --detach \
--name tp0-nginx \
--publish :80 \
nginx:stableUnable to find image 'nginx:stable' locally
stable: Pulling from library/nginx
ecc510c1e359: Pulling fs layer
f4616bb1be1c: Pulling fs layer
f1a6a629b824: Pulling fs layer
3d774efa34e3: Pulling fs layer
cb44c3fe542b: Pulling fs layer
121907e00c1c: Pulling fs layer
220a6ac36368: Pulling fs layer
3d774efa34e3: Waiting
220a6ac36368: Waiting
cb44c3fe542b: Waiting
121907e00c1c: Waiting
f1a6a629b824: Downloading 628B/628B
f1a6a629b824: Verifying Checksum
f1a6a629b824: Download complete
ecc510c1e359: Downloading 310.7kB/29.84MB
f4616bb1be1c: Downloading 343.5kB/33.77MB
ecc510c1e359: Downloading 5.914MB/29.84MB
f4616bb1be1c: Downloading 5.16MB/33.77MB
ecc510c1e359: Downloading 11.21MB/29.84MB
f4616bb1be1c: Downloading 11.35MB/33.77MB
ecc510c1e359: Downloading 16.81MB/29.84MB
f4616bb1be1c: Downloading 16.86MB/33.77MB
ecc510c1e359: Downloading 22.72MB/29.84MB
3d774efa34e3: Downloading 954B/954B
3d774efa34e3: Verifying Checksum
3d774efa34e3: Download complete
f4616bb1be1c: Downloading 24.08MB/33.77MB
ecc510c1e359: Downloading 28.95MB/29.84MB
f4616bb1be1c: Downloading 30.97MB/33.77MB
ecc510c1e359: Download complete
f4616bb1be1c: Verifying Checksum
f4616bb1be1c: Download complete
ecc510c1e359: Extracting 327.7kB/29.84MB
ecc510c1e359: Extracting 2.949MB/29.84MB
ecc510c1e359: Extracting 5.571MB/29.84MB
121907e00c1c: Downloading 1.21kB/1.21kB
121907e00c1c: Downloading 1.21kB/1.21kB
121907e00c1c: Download complete
220a6ac36368: Downloading 1.398kB/1.398kB
220a6ac36368: Verifying Checksum
220a6ac36368: Download complete
ecc510c1e359: Extracting 8.192MB/29.84MB
ecc510c1e359: Extracting 10.16MB/29.84MB
ecc510c1e359: Extracting 12.12MB/29.84MB
ecc510c1e359: Extracting 15.4MB/29.84MB
ecc510c1e359: Extracting 18.35MB/29.84MB
ecc510c1e359: Extracting 21.63MB/29.84MB
ecc510c1e359: Extracting 24.9MB/29.84MB
cb44c3fe542b: Downloading 404B/404B
cb44c3fe542b: Verifying Checksum
cb44c3fe542b: Download complete
ecc510c1e359: Extracting 26.21MB/29.84MB
ecc510c1e359: Extracting 28.18MB/29.84MB
ecc510c1e359: Extracting 28.84MB/29.84MB
ecc510c1e359: Extracting 29.16MB/29.84MB
ecc510c1e359: Extracting 29.82MB/29.84MB
ecc510c1e359: Extracting 29.84MB/29.84MB
ecc510c1e359: Pull complete
f4616bb1be1c: Extracting 360.4kB/33.77MB
f4616bb1be1c: Extracting 2.884MB/33.77MB
f4616bb1be1c: Extracting 5.767MB/33.77MB
f4616bb1be1c: Extracting 9.372MB/33.77MB
f4616bb1be1c: Extracting 12.62MB/33.77MB
f4616bb1be1c: Extracting 14.42MB/33.77MB
f4616bb1be1c: Extracting 17.3MB/33.77MB
f4616bb1be1c: Extracting 20.55MB/33.77MB
f4616bb1be1c: Extracting 24.15MB/33.77MB
f4616bb1be1c: Extracting 27.03MB/33.77MB
f4616bb1be1c: Extracting 29.92MB/33.77MB
f4616bb1be1c: Extracting 31MB/33.77MB
f4616bb1be1c: Extracting 31.36MB/33.77MB
f4616bb1be1c: Extracting 33.77MB/33.77MB
f4616bb1be1c: Pull complete
f1a6a629b824: Extracting 628B/628B
f1a6a629b824: Extracting 628B/628B
f1a6a629b824: Pull complete
3d774efa34e3: Extracting 954B/954B
3d774efa34e3: Extracting 954B/954B
3d774efa34e3: Pull complete
cb44c3fe542b: Extracting 404B/404B
cb44c3fe542b: Extracting 404B/404B
cb44c3fe542b: Pull complete
121907e00c1c: Extracting 1.21kB/1.21kB
121907e00c1c: Extracting 1.21kB/1.21kB
121907e00c1c: Pull complete
220a6ac36368: Extracting 1.398kB/1.398kB
220a6ac36368: Extracting 1.398kB/1.398kB
220a6ac36368: Pull complete
Digest: sha256:9bf97bd7714f5e24c1ccd545ecb9eb5435cb6d109c97cebb15e7e455e0239edb
Status: Downloaded newer image for nginx:stable
ad77854ffb019c40348b48d146643b5ba984c61628bea15032b32dafa2622c6c
Vérifier qu’il est bien lancé :
docker container lsCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
ad77854ffb01 nginx:stable "/docker-entrypoint.…" 3 seconds ago Up Less than a second 0.0.0.0:32768->80/tcp, [::]:32768->80/tcp tp0-nginx
7202cb0885be ghcr.io/ebpro/solen:quarto-full-build-20261010T172146Z "bash -lc 'source /h…" About a minute ago Up About a minute quarto-render-38521027713
Il est accessible via le port 8080 de l’hôte avec un navigateur web ou curl :
Tester :
curl --max-time 30 --include http://localhost:8080curl: (7) Failed to connect to dind port 8080 after 0 ms: Couldn’t connect to server (skipped: no DIND host in CI)
Les 10 derniers logs du conteneur peuvent être consultés avec :
docker logs tp0-nginx --tail 102026/10/14 06:21:26 [notice] 1#1: start worker process 51
2026/10/14 06:21:26 [notice] 1#1: start worker process 52
2026/10/14 06:21:26 [notice] 1#1: start worker process 53
2026/10/14 06:21:26 [notice] 1#1: start worker process 54
2026/10/14 06:21:26 [notice] 1#1: start worker process 55
2026/10/14 06:21:26 [notice] 1#1: start worker process 56
2026/10/14 06:21:26 [notice] 1#1: start worker process 57
2026/10/14 06:21:26 [notice] 1#1: start worker process 58
2026/10/14 06:21:26 [notice] 1#1: start worker process 59
2026/10/14 06:21:26 [notice] 1#1: start worker process 60
Le conteneur peut être arrêté avec :
docker stop tp0-nginxtp0-nginx
Les conteneurs y compris arrêtés peuvent être listés avec :
docker container ls --allCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
ad77854ffb01 nginx:stable "/docker-entrypoint.…" 4 seconds ago Exited (0) Less than a second ago tp0-nginx
7202cb0885be ghcr.io/ebpro/solen:quarto-full-build-20261010T172146Z "bash -lc 'source /h…" About a minute ago Up About a minute quarto-render-38521027713
et supprimé avec :
docker rm --force tp0-nginxtp0-nginx
Un conteneur = un service/processus isolé
Pour relier le système de fichier de l’hôte et celui du conteneur, on utilise des volumes.
Créer un dossier www/ sur l’hôte avec une page HTML simple :
mkdir -p www
echo "<h1>Hello from host</h1>" > www/index.htmlLancer un serveur web nginx en montant le dossier www/ de l’hôte dans le dossier /usr/share/nginx/html du conteneur (en lecture seule avec :ro) :
docker rm -f tp0-nginx >/dev/null 2>&1 || true
docker run --label ebpro-render=true --detach \
--name tp0-nginx \
--publish :80 \
--volume "$PWD/www":/usr/share/nginx/html:ro \
nginx:stableIl est accessible via le port 8080 de l’hôte avec un navigateur web ou curl :
curl est utilisé ici pour afficher les headers HTTP et le contenu de la page.
curl --max-time 30 --include http://localhost:8080curl: (7) Failed to connect to dind port 8080 after 0 ms: Couldn't connect to server
curl failed or timed out
Modifier www/index.html sur l’hôte et rafraîchir la page ou relancer curl.
echo "<h1>Hello from host - updated</h1>" > www/index.html
curl --max-time 30 --include http://localhost:8080Nettoyage :
Les données ne vivent pas dans le conteneur, il doit être éphémère
Il est important de comprendre la différence entre un conteneur et une image. Il est possible d’executer des conteneurs en mode interactif pour explorer leur contenu et interagir avec eux.
Il est déconseillé d’installer des logiciels directement dans un conteneur en production.
docker run --label ebpro-render=true --rm ubuntu:22.04 </dev/nullDans le conteneur, exécuter les commandes suivantes pour explorer le système, créer un fichier et installer curl.
cat /etc/os-release
uname -a
echo "Hello from inside the container" > /tmp/hello.txt
apt update && apt install -y curl
curl --max-time 30 --include https://example.comquitter le conteneur avec la commande exit (ou Ctrl+D).
Unable to find image 'ubuntu:22.04' locally
22.04: Pulling from library/ubuntu
98c4455a9898: Pulling fs layer
98c4455a9898: Downloading 310.7kB/29.75MB
98c4455a9898: Downloading 7.782MB/29.75MB
98c4455a9898: Downloading 14.63MB/29.75MB
98c4455a9898: Downloading 22.72MB/29.75MB
98c4455a9898: Verifying Checksum
98c4455a9898: Download complete
98c4455a9898: Extracting 327.7kB/29.75MB
98c4455a9898: Extracting 3.277MB/29.75MB
98c4455a9898: Extracting 5.898MB/29.75MB
98c4455a9898: Extracting 7.864MB/29.75MB
98c4455a9898: Extracting 9.175MB/29.75MB
98c4455a9898: Extracting 11.14MB/29.75MB
98c4455a9898: Extracting 14.75MB/29.75MB
98c4455a9898: Extracting 18.02MB/29.75MB
98c4455a9898: Extracting 21.63MB/29.75MB
98c4455a9898: Extracting 24.58MB/29.75MB
98c4455a9898: Extracting 25.56MB/29.75MB
98c4455a9898: Extracting 25.89MB/29.75MB
98c4455a9898: Extracting 27.85MB/29.75MB
98c4455a9898: Extracting 28.51MB/29.75MB
98c4455a9898: Extracting 29.49MB/29.75MB
98c4455a9898: Extracting 29.75MB/29.75MB
98c4455a9898: Pull complete
Digest: sha256:5ec03bb3441e8b0bf3b4f9cd4629a1ae763010dc3035bb8da3ae6cf026486401
Status: Downloaded newer image for ubuntu:22.04
debconf: delaying package configuration, since apt-utils is not installed
Selecting previously unselected package openssl.
(Reading database ... 4393 files and directories currently installed.)
Preparing to unpack .../00-openssl_3.0.2-0ubuntu1.30_amd64.deb ...
Unpacking openssl (3.0.2-0ubuntu1.30) ...
Selecting previously unselected package ca-certificates.
Preparing to unpack .../01-ca-certificates_20260601~22.04.1_all.deb ...
Unpacking ca-certificates (20260601~22.04.1) ...
Selecting previously unselected package libnghttp2-14:amd64.
Preparing to unpack .../02-libnghttp2-14_1.43.0-1ubuntu0.4_amd64.deb ...
Unpacking libnghttp2-14:amd64 (1.43.0-1ubuntu0.4) ...
Selecting previously unselected package libpsl5:amd64.
Preparing to unpack .../03-libpsl5_0.21.0-1.2build2_amd64.deb ...
Unpacking libpsl5:amd64 (0.21.0-1.2build2) ...
Selecting previously unselected package publicsuffix.
Preparing to unpack .../04-publicsuffix_20211207.1025-1_all.deb ...
Unpacking publicsuffix (20211207.1025-1) ...
Selecting previously unselected package libbrotli1:amd64.
Preparing to unpack .../05-libbrotli1_1.0.9-2build6_amd64.deb ...
Unpacking libbrotli1:amd64 (1.0.9-2build6) ...
Selecting previously unselected package libsasl2-modules-db:amd64.
Preparing to unpack .../06-libsasl2-modules-db_2.1.27+dfsg2-3ubuntu1.2_amd64.deb ...
Unpacking libsasl2-modules-db:amd64 (2.1.27+dfsg2-3ubuntu1.2) ...
Selecting previously unselected package libsasl2-2:amd64.
Preparing to unpack .../07-libsasl2-2_2.1.27+dfsg2-3ubuntu1.2_amd64.deb ...
Unpacking libsasl2-2:amd64 (2.1.27+dfsg2-3ubuntu1.2) ...
Selecting previously unselected package libldap-2.5-0:amd64.
Preparing to unpack .../08-libldap-2.5-0_2.5.20+dfsg-0ubuntu0.22.04.1_amd64.deb ...
Unpacking libldap-2.5-0:amd64 (2.5.20+dfsg-0ubuntu0.22.04.1) ...
Selecting previously unselected package librtmp1:amd64.
Preparing to unpack .../09-librtmp1_2.4+20151223.gitfa8646d.1-2build4_amd64.deb ...
Unpacking librtmp1:amd64 (2.4+20151223.gitfa8646d.1-2build4) ...
Selecting previously unselected package libssh-4:amd64.
Preparing to unpack .../10-libssh-4_0.9.6-2ubuntu0.22.04.8_amd64.deb ...
Unpacking libssh-4:amd64 (0.9.6-2ubuntu0.22.04.8) ...
Selecting previously unselected package libcurl4:amd64.
Preparing to unpack .../11-libcurl4_7.81.0-1ubuntu1.29_amd64.deb ...
Unpacking libcurl4:amd64 (7.81.0-1ubuntu1.29) ...
Selecting previously unselected package curl.
Preparing to unpack .../12-curl_7.81.0-1ubuntu1.29_amd64.deb ...
Unpacking curl (7.81.0-1ubuntu1.29) ...
Selecting previously unselected package libldap-common.
Preparing to unpack .../13-libldap-common_2.5.20+dfsg-0ubuntu0.22.04.1_all.deb ...
Unpacking libldap-common (2.5.20+dfsg-0ubuntu0.22.04.1) ...
Selecting previously unselected package libsasl2-modules:amd64.
Preparing to unpack .../14-libsasl2-modules_2.1.27+dfsg2-3ubuntu1.2_amd64.deb ...
Unpacking libsasl2-modules:amd64 (2.1.27+dfsg2-3ubuntu1.2) ...
Setting up libpsl5:amd64 (0.21.0-1.2build2) ...
Setting up libbrotli1:amd64 (1.0.9-2build6) ...
Setting up libsasl2-modules:amd64 (2.1.27+dfsg2-3ubuntu1.2) ...
Setting up libnghttp2-14:amd64 (1.43.0-1ubuntu0.4) ...
Setting up libldap-common (2.5.20+dfsg-0ubuntu0.22.04.1) ...
Setting up libsasl2-modules-db:amd64 (2.1.27+dfsg2-3ubuntu1.2) ...
Setting up librtmp1:amd64 (2.4+20151223.gitfa8646d.1-2build4) ...
Setting up libsasl2-2:amd64 (2.1.27+dfsg2-3ubuntu1.2) ...
Setting up libssh-4:amd64 (0.9.6-2ubuntu0.22.04.8) ...
Setting up openssl (3.0.2-0ubuntu1.30) ...
Setting up publicsuffix (20211207.1025-1) ...
Setting up libldap-2.5-0:amd64 (2.5.20+dfsg-0ubuntu0.22.04.1) ...
Setting up ca-certificates (20260601~22.04.1) ...
debconf: unable to initialize frontend: Dialog
debconf: (TERM is not set, so the dialog frontend is not usable.)
debconf: falling back to frontend: Readline
debconf: unable to initialize frontend: Readline
debconf: (Can't locate Term/ReadLine.pm in @INC (you may need to install the Term::ReadLine module) (@INC contains: /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.34.0 /usr/local/share/perl/5.34.0 /usr/lib/x86_64-linux-gnu/perl5/5.34 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl-base /usr/lib/x86_64-linux-gnu/perl/5.34 /usr/share/perl/5.34 /usr/local/lib/site_perl) at /usr/share/perl5/Debconf/FrontEnd/Readline.pm line 7.)
debconf: falling back to frontend: Teletype
Updating certificates in /etc/ssl/certs...
121 added, 0 removed; done.
Setting up libcurl4:amd64 (7.81.0-1ubuntu1.29) ...
Setting up curl (7.81.0-1ubuntu1.29) ...
Processing triggers for libc-bin (2.35-0ubuntu3.15) ...
Processing triggers for ca-certificates (20260601~22.04.1) ...
Updating certificates in /etc/ssl/certs...
0 added, 0 removed; done.
Running hooks in /etc/ca-certificates/update.d...
done.
Linux 47b3a6be7ea2 6.8.0-142-generic #142-Ubuntu SMP PREEMPT_DYNAMIC Wed Sep 2 14:24:27 UTC 2026 x86_64 x86_64 x86_64 GNU/Linux
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
100 577 0 577 0 0 3566 0 --:--:-- --:--:-- --:--:-- 3583
HTTP/2 200
date: Wed, 14 Oct 2026 06:21:57 GMT
content-type: text/html; charset=utf-8
server: cloudflare
last-modified: Tue, 13 Oct 2026 20:08:28 GMT
allow: GET, HEAD
accept-ranges: bytes
age: 7781
cf-cache-status: HIT
cf-ray: a4a47ca41a5f57fe-CDG
alt-svc: h3=":443"; ma=86400
<!doctype html><html lang=en><head><meta charset=utf-8><link rel=icon href=data:,><meta name=viewport content="width=device-width,initial-scale=1"><title>Example Domain</title><style>html{color-scheme:light dark;background:light-dark(#eee,#222)}body{font:16px/1.6 system-ui,sans-serif;max-width:26em;margin:auto;padding:25vh 2em 2em;text-align:center}</style></head><body><p>This domain is for use in documentation examples without needing permission. This is not a service; avoid relying on it for testing and monitoring purposes.</p><script src=/s.js></script></body></html>
Relancer :
docker run --label ebpro-render=true --rm ubuntu:22.04 bash </dev/null
cat /tmp/hello.txt # ❌ disparu
curl --max-time 30 --include https://example.com # ❌ curl non installéCe qui n’est pas dans une image est perdu
Pour rendre l’installation reproductible et persistante, il faut créer une image. L’approche standard est d’écrire un fichier Dockerfile décrivant l’image.
Créer un Dockerfile qui installe curl (RUN) dans une image basée sur ubuntu:22.04 (FROM) et qui lance bash par défaut (CMD).
Construire l’image Docker à partir d’un Dockerfile dans le dossier courant (.) avec le tag tp0-ubuntu-curl :
docker build --tag tp0-ubuntu-curl .Tester en mode interactif en exécutant la commande curl --max-time 30 --include https://example.com dans le conteneur :
docker run --label ebpro-render=true --rm tp0-ubuntu-curl </dev/nullla commande peut aussi être passée en paramètre du docker run :
docker run --label ebpro-render=true --rm tp0-ubuntu-curl \
curl --max-time 30 --include https://example.com % Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
100 577 0 577 0 0 3733 0 --:--:-- --:--:-- --:--:-- 3746
HTTP/2 200
date: Wed, 14 Oct 2026 06:22:18 GMT
content-type: text/html; charset=utf-8
server: cloudflare
last-modified: Tue, 13 Oct 2026 20:08:28 GMT
allow: GET, HEAD
accept-ranges: bytes
age: 7802
cf-cache-status: HIT
cf-ray: a4a47d24da5704a4-CDG
alt-svc: h3=":443"; ma=86400
<!doctype html><html lang=en><head><meta charset=utf-8><link rel=icon href=data:,><meta name=viewport content="width=device-width,initial-scale=1"><title>Example Domain</title><style>html{color-scheme:light dark;background:light-dark(#eee,#222)}body{font:16px/1.6 system-ui,sans-serif;max-width:26em;margin:auto;padding:25vh 2em 2em;text-align:center}</style></head><body><p>This domain is for use in documentation examples without needing permission. This is not a service; avoid relying on it for testing and monitoring purposes.</p><script src=/s.js></script></body></html>
En suivant la même approche, il est possible de créer une image contenant une application Python simple.
Créer une structure de dossiers app/ avec une application serveur Web minimale en Python :
app
├── Dockerfile
└── app.py
1 directory, 2 files
L’application Python
app/app.py
Un fichier Dockerfile qui construit l’image de l’application Python en utilisant l’image officielle python:3.11-slim comme base, en copiant le fichier app.py dans le conteneur et en définissant la commande par défaut pour exécuter l’application.
Construire l’image Docker depuis le dossier app/ avec le tag tp0-app:0.0.1 :
docker build --tag tp0-app:0.0.1 .Exécuter le conteneur en mappant le port 5000 du conteneur (sur lequel l’application écoute) sur le port 5000 de l’hôte :
docker rm -f tp0-app >/dev/null 2>&1 || true
docker run --label ebpro-render=true --detach \
--name tp0-app \
--publish :5000 \
tp0-app:0.0.115e937879c3ea9190cb1fe99ffe29991d09d9f3bc055cd3dcbafc850a73beebc
Tester l’application avec curl depuis l’hôte :
curl --max-time 30 --include http://localhost:5000curl: (7) Failed to connect to dind port 5000 after 0 ms: Couldn't connect to server
(skipped: no DIND host in CI)
Nettoyer le conteneur (arrêt et suppression) :
docker stop tp0-app
docker rm tp0-apptp0-app
tp0-app
Il est possible de faire fonctionner plusieurs conteneurs ensemble via un réseau Docker. Dans cet exercice, nous allons créer un réseau Docker et y connecter le conteneur de l’application Python et et autre conteneur curl pour tester l’application.
Créer un réseau (virtuel) Docker nommé tp0-net :
docker network create tp0-net781cae1654efe670c456db53f3632b88fde202ccdb9ad944b994cdd82f768ed7
Lancer le conteneur de l’application Python dans ce réseau :
docker rm -f tp0-app >/dev/null 2>&1 || true
docker run --label ebpro-render=true --detach \
--name tp0-app \
--network tp0-net \
tp0-app:0.0.19b055fc0666ff464ef05dae8bf22a988b4eb0192e9c0ea987d22bff3fceae445
Tester l’application avec un conteneur curl connecté au même réseau Docker, en utilisant le nom du conteneur tp0-app comme hostname pour le service :
#| echo: true
#| output: asis
docker run --label ebpro-render=true --rm \
--network tp0-net \
curlimages/curl --max-time 30 --include http://tp0-app:5000Nettoyage :
Les conteneurs communiquent via des réseaux virtuels et des noms DNS internes
Les conteneurs permettent de déployer des applications complexes de manière reproductible et en isolant les différentes parties.