Version : 2024.01

Dernière mise-à-jour :

DOF605 - Docker Compose, Docker Machine et Docker Swarm

Contenu du Module

DOF605 - Docker Compose, Docker Machine et Docker Swarm

Contenu du Module

LAB #1 - Docker Compose

1.1 - Installation

1.2 - Installer Wordpress avec Docker Compose

LAB #2 - Docker Machine

2.1 - Présentation

2.2 - Création de Machines Virtuelles Docker

2.3 - Lister les VM Docker

2.4 - Obtenir l'adresse IP des VM

2.5 - Se connecter à une VM Docker

LAB #3 - Docker Swarm

3.1 - Présentation

3.2 - Initialiser Docker Swarm

3.3 - Le Statut Leader

3.4 - Rejoindre le Swarm

3.5 - Consulter les Informations de Swarm

3.6 - Démarrer un Service

3.7 - Augmentation et Réduction du Service

3.8 - Consulter le Statut d'un Nœud

3.9 - Haute Disponibilité

3.10 - Supprimer un Service

3.11 - Sauvegarder Docker Swarm

3.12 - Restaurer Docker Swarm

LAB #1 - Docker Compose

Docker Compose est un utilitaire de compilation d'images et de gestion de conteneurs multiples, tous intégrés dans une seule et unique application logicielle. Son rôle est de rendre plus aisée la manipulation d'éléments multiples interconnectés. Pour ce faire, Docker Compose utilise un fichier dénommé docker-compose.yml au format YAML.

Ce fichier, appelé par la commande docker-compose build commence avec un mot clef image ou build selon que l'image est récupérée sur un registre ou provient du répertoire cité dans le fichier. Le reste du fichier contient des instructions pour définir la compilation des images constituantes, pour lier des conteneurs et pour définir l'environnement.

Une fois totalement construite, l'application peut ensuite être pilotée très simplement par l'utilisation de la commande docker-compose qui réagit de la même manière que la commande docker mais cette fois-ci sur tous les conteneurs définis dans le fichier docker-compose.yml.

De cette façon il est possible de démarrer l'application avec la commande docker-compose up, de l'arrêter avec la commande docker-compose stop ou de la redémarrer avec la commande docker-compose restart. De la même manière que la commande docker, la commande docker-compose donne accès aux journaux grâce à la commande docker-compose logs.

1.1 - Installation

Récupérez docker-compose avec curl :

root@debian11:~# curl -L "https://github.com/docker/compose/releases/download/v2.0.1/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
% 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 24.7M 100 24.7M 0 0 45.5M 0 --:--:-- --:--:-- --:--:-- 45.5M

Vérifiez la version installée :

root@debian11:~# docker-compose --version
Docker Compose version v2.0.1

Rendez /usr/local/bin/docker-compose exécutable :

root@debian11:~# chmod +x /usr/local/bin/docker-compose
root@debian11:~# ls -l /usr/local/bin/docker-compose
-rwxr-xr-x 1 root root 25907200 Dec 16 12:15 /usr/local/bin/docker-compose

Les options de la commande docker-compose sont :

root@debian11:~# docker-compose --help
Usage: docker compose [OPTIONS] COMMAND
Docker Compose
Options:
--ansi string Control when to print ANSI control
characters ("never"|"always"|"auto")
(default "auto")
--compatibility Run compose in backward compatibility mode
--env-file string Specify an alternate environment file.
-f, --file stringArray Compose configuration files
--profile stringArray Specify a profile to enable
--project-directory string Specify an alternate working directory
(default: the path of the Compose file)
-p, --project-name string Project name
Commands:
build Build or rebuild services
convert Converts the compose file to platform's canonical format
cp Copy files/folders between a service container and the local filesystem
create Creates containers for a service.
down Stop and remove containers, networks
events Receive real time events from containers.
exec Execute a command in a running container.
images List images used by the created containers
kill Force stop service containers.
logs View output from containers
ls List running compose projects
pause pause services
port Print the public port for a port binding.
ps List containers
pull Pull service images
push Push service images
restart Restart containers
rm Removes stopped service containers
run Run a one-off command on a service.
start Start services
stop Stop services
top Display the running processes
unpause unpause services
up Create and start containers
Run 'docker compose COMMAND --help' for more information on a command.

1.2 - Installer Wordpress avec Docker Compose

Créez maintenant le répertoire wordpress1 dans /root :

root@debian9:~# mkdir wordpress1

Placez-vous dans le répertoire et créer le fichier docker-compose.yaml

root@debian9:~# cd wordpress1
root@debian9:~/wordpress1# vi docker-compose.yaml
root@debian9:~/wordpress1# cat docker-compose.yaml
version: "3.3"
services:
db:
image: mysql:5.7
volumes:
- db_data:/var/lib/mysql
restart: always
environment:
MYSQL_ROOT_PASSWORD: fenestros
MYSQL_DATABASE: wordpress
MYSQL_USER: wordpress
MYSQL_PASSWORD: wordpress
wordpress:
depends_on:
- db
image: wordpress:latest
ports:
- "8000:80"
restart: always
environment:
WORDPRESS_DB_HOST: db:3306
WORDPRESS_DB_USER: wordpress
WORDPRESS_DB_PASSWORD: wordpress
WORDPRESS_DB_NAME: wordpress
volumes:
db_data: {}

Exécutez la commande docker-compose :

root@debian11:~/wordpress1# docker-compose up -d
[+] Running 12/12
⠿ db Pulled 16.0s
⠿ 20e4dcae4c69 Pull complete 5.7s
⠿ 1c56c3d4ce74 Pull complete 5.8s
⠿ e9f03a1c24ce Pull complete 5.9s
⠿ 68c3898c2015 Pull complete 6.2s
⠿ 6b95a940e7b6 Pull complete 6.3s
⠿ 90986bb8de6e Pull complete 6.3s
⠿ ae71319cb779 Pull complete 7.4s
⠿ ffc89e9dfd88 Pull complete 7.4s
⠿ 43d05e938198 Pull complete 15.2s
⠿ 064b2d298fba Pull complete 15.3s
⠿ df9a4d85569b Pull complete 15.3s
[+] Running 4/4
⠿ Network wordpress1_default Created 0.1s
⠿ Volume "wordpress1_db_data" Created 0.0s
⠿ Container wordpress1-db-1 Started 10.7s
⠿ Container wordpress1-wordpress-1 Started 1.5s

Vérifiez que le Wordpress fonctionne :

root@debian11:~/wordpress1# lynx --dump http://10.0.2.46:8000
WordPress
Select a default language [English (United States)__________]
Continue
root@debian11:~/wordpress1# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
9475874569e1 wordpress:latest "docker-entrypoint.s…" 51 seconds ago Up 49 seconds 0.0.0.0:8000->80/tcp, :::8000->80/tcp wordpress1-wordpress-1
5983cdf711ec mysql:5.7 "docker-entrypoint.s…" About a minute ago Up 50 seconds 3306/tcp, 33060/tcp wordpress1-db-1
cf27f30654d2 dockersamples/examplevotingapp_worker "dotnet Worker.dll" 20 hours ago Up 20 hours worker
33a264a36bdc dockersamples/examplevotingapp_result "/usr/bin/tini -- no…" 20 hours ago Up 20 hours 0.0.0.0:5001->80/tcp, :::5001->80/tcp result
81e6fcb9f692 dockersamples/examplevotingapp_vote "gunicorn app:app -b…" 20 hours ago Up 20 hours 0.0.0.0:5000->80/tcp, :::5000->80/tcp vote
5083545dcbf8 postgres:9.4 "docker-entrypoint.s…" 20 hours ago Up 20 hours 5432/tcp db
227554e3e4c1 redis "docker-entrypoint.s…" 20 hours ago Up 20 hours 6379/tcp redis
63fec083f4d6 wordpress "docker-entrypoint.s…" 21 hours ago Up 21 hours 10.0.2.46:80->80/tcp wordpress
db3732939266 mysql:latest "docker-entrypoint.s…" 21 hours ago Up 21 hours 3306/tcp, 33060/tcp wordpressdb
57e92a8b25d7 centos "/bin/bash" 21 hours ago Up 21 hours centos3
fc417b22a20d centos "/bin/bash" 21 hours ago Up 21 hours centos2
cb2875ab1059 centos "/bin/bash" 21 hours ago Up 21 hours centos1
2126924504d8 centos "/bin/bash" 21 hours ago Up 21 hours resotest
root@debian11:~/wordpress1# docker inspect wordpress1-wordpress-1 | grep IPAddress
"SecondaryIPAddresses": null,
"IPAddress": "",
"IPAddress": "172.18.0.3",
root@debian11:~/wordpress1# lynx --dump http://172.18.0.3
WordPress
Select a default language [English (United States)__________]
Continue

Important - La commande docker-compose up est une abréviation des commandes docker-compose build && docker-compose run. L'option -d a le même effet de son homologue de la commande docker.

LAB #2 - Docker Machine

2.1 - Présentation

Docker Machine est un outil qui vous permet d'installer docker sur des hôtes virtuels et de gérer les hôtes en utilisant des commandes spécifiques à docker-machine. Il est donc possible d'utiliser cet outil pour créer des hôtes docker localement, sur le réseau, dans un data center ou dans le cloud (Azure, AWS, Digital Ocean par exemple).

Le jeu de commandes de docker-machine permet de démarrer, surveiller, arrêter et re-démarrer un hôte géré, de mettre à jour le client/daemon docker et de configurer un client docker afin qu'il “parle” à votre machine hôte.

Pour installer docker-machine sur votre VM debian11, utilisez la commande suivante :

root@debian11:~/wordpress1# cd ~
root@debian11:~# curl -L https://github.com/docker/machine/releases/download/v0.16.2/docker-machine-`uname -s`-`uname -m` >/tmp/docker-machine && chmod +x /tmp/docker-machine && cp /tmp/docker-machine /usr/local/bin/docker-machine
% 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 32.6M 100 32.6M 0 0 48.5M 0 --:--:-- --:--:-- --:--:-- 48.5M

2.2 - Création de Machines Virtuelles Docker

La création d'une machine se fait simplement en utilisant la commande docker-machine avec la sous-commande create. Cette sous-commande prend l'option –driver ou -d qui indique le fournisseur à utiliser :

Fournisseur	driver
Amazon Web Services	amazonec2
Digital Ocean	digitalocean
Exoscale	exoscale
Google Compute Engine	google
IBM Softlayer	softlayer
Microsoft Hyper-V	hyperv
Microsoft Azure	azure
OpenStack	openstack
Oracle VirtualBox	virtualbox
Rackspace	rackspace
VMware Fusion	vmwarefusion
VMware vCloud Air	vmwarevcloudair
VMware vSphere	vmwarevsphere

Commencez par installer Oracle VirtualBox:

root@debian11:~# apt install virtualbox-6.1 -y
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following packages were automatically installed and are no longer required:
libopengl0 linux-headers-5.10.0-15-amd64 linux-headers-5.10.0-15-common
Use 'apt autoremove' to remove them.
Recommended packages:
linux-image
The following packages will be upgraded:
virtualbox-6.1
1 upgraded, 0 newly installed, 0 to remove and 16 not upgraded.
Need to get 95.8 MB of archives.
After this operation, 53.2 kB disk space will be freed.
Get:1 http://download.virtualbox.org/virtualbox/debian bullseye/contrib amd64 virtualbox-6.1 amd64 6.1.48-159471~Debian~bullseye [95.8 MB]
Fetched 95.8 MB in 3s (31.4 MB/s)
apt-listchanges: Reading changelogs...
Preconfiguring packages ...
(Reading database ... 166797 files and directories currently installed.)
Preparing to unpack .../virtualbox-6.1_6.1.48-159471~Debian~bullseye_amd64.deb ...
Unpacking virtualbox-6.1 (6.1.48-159471~Debian~bullseye) over (6.1.46-158378~Debian~bullseye) ...
Setting up virtualbox-6.1 (6.1.48-159471~Debian~bullseye) ...
addgroup: The group `vboxusers' already exists as a system group. Exiting.
Processing triggers for hicolor-icon-theme (0.17-2) ...
Processing triggers for shared-mime-info (2.0-1) ...
Processing triggers for mailcap (3.69) ...
Processing triggers for desktop-file-utils (0.26-1) ...

Créez le fichier /etc/vbox/networks.conf :

root@debian11:~# vi /etc/vbox/networks.conf
root@debian11:~# cat /etc/vbox/networks.conf
* 10.0.0.0/8 192.168.0.0/16

Créez maintenant la machine virtuelle manager1 :

root@debian11:~# docker-machine create --driver virtualbox manager1
Running pre-create checks...
(manager1) Image cache directory does not exist, creating it at /root/.docker/machine/cache...
(manager1) No default Boot2Docker ISO found locally, downloading the latest release...
(manager1) Latest release for github.com/boot2docker/boot2docker is v19.03.12
(manager1) Downloading /root/.docker/machine/cache/boot2docker.iso from https://github.com/boot2docker/boot2docker/releases/download/v19.03.12/boot2docker.iso...
(manager1) 0%....10%....20%....30%....40%....50%....60%....70%....80%....90%....100%
Creating machine...
(manager1) Copying /root/.docker/machine/cache/boot2docker.iso to /root/.docker/machine/machines/manager1/boot2docker.iso...
(manager1) Creating VirtualBox VM...
(manager1) Creating SSH key...
(manager1) Starting the VM...
(manager1) Check network to re-create if needed...
(manager1) Found a new host-only adapter: "vboxnet0"
(manager1) Waiting for an IP...
Waiting for machine to be running, this may take a few minutes...
Detecting operating system of created instance...
Waiting for SSH to be available...
Detecting the provisioner...
Provisioning with boot2docker...
Copying certs to the local machine directory...
Copying certs to the remote machine...
Setting Docker configuration on the remote daemon...
Checking connection to Docker...
Docker is up and running!
To see how to connect your Docker Client to the Docker Engine running on this virtual machine, run: docker-machine env manager1

Les options de la commande docker-machine sont :

root@debian11:~# docker-machine --help
Usage: docker-machine [OPTIONS] COMMAND [arg...]
Create and manage machines running Docker.
Version: 0.16.2, build bd45ab13
Author:
Docker Machine Contributors - <https://github.com/docker/machine>
Options:
--debug, -D Enable debug mode
--storage-path, -s "/root/.docker/machine" Configures storage path [$MACHINE_STORAGE_PATH]
--tls-ca-cert CA to verify remotes against [$MACHINE_TLS_CA_CERT]
--tls-ca-key Private key to generate certificates [$MACHINE_TLS_CA_KEY]
--tls-client-cert Client cert to use for TLS [$MACHINE_TLS_CLIENT_CERT]
--tls-client-key Private key used in client TLS auth [$MACHINE_TLS_CLIENT_KEY]
--github-api-token Token to use for requests to the Github API [$MACHINE_GITHUB_API_TOKEN]
--native-ssh Use the native (Go-based) SSH implementation. [$MACHINE_NATIVE_SSH]
--bugsnag-api-token BugSnag API token for crash reporting [$MACHINE_BUGSNAG_API_TOKEN]
--help, -h show help
--version, -v print the version
Commands:
active Print which machine is active
config Print the connection config for machine
create Create a machine
env Display the commands to set up the environment for the Docker client
inspect Inspect information about a machine
ip Get the IP address of a machine
kill Kill a machine
ls List machines
provision Re-provision existing machines
regenerate-certs Regenerate TLS Certificates for a machine
restart Restart a machine
rm Remove a machine
ssh Log into or run a command on a machine with SSH.
scp Copy files between machines
mount Mount or unmount a directory from a machine with SSHFS.
start Start a machine
status Get the status of a machine
stop Stop a machine
upgrade Upgrade a machine to the latest version of Docker
url Get the URL of a machine
version Show the Docker Machine version or a machine docker version
help Shows a list of commands or help for one command
Run 'docker-machine COMMAND --help' for more information on a command.

Les options de la sous-commande create de la commande docker-machine sont :

root@debian11:~# docker-machine create --help
Usage: docker-machine create [OPTIONS] [arg...]
Create a machine
Description:
Run 'docker-machine create --driver name --help' to include the create flags for that driver in the help text.
Options:
--driver, -d "virtualbox" Driver to create machine with. [$MACHINE_DRIVER]
--engine-env [--engine-env option --engine-env option] Specify environment variables to set in the engine
--engine-insecure-registry [--engine-insecure-registry option --engine-insecure-registry option] Specify insecure registries to allow with the created engine
--engine-install-url "https://get.docker.com" Custom URL to use for engine installation [$MACHINE_DOCKER_INSTALL_URL]
--engine-label [--engine-label option --engine-label option] Specify labels for the created engine
--engine-opt [--engine-opt option --engine-opt option] Specify arbitrary flags to include with the created engine in the form flag=value
--engine-registry-mirror [--engine-registry-mirror option --engine-registry-mirror option] Specify registry mirrors to use [$ENGINE_REGISTRY_MIRROR]
--engine-storage-driver Specify a storage driver to use with the engine
--swarm Configure Machine to join a Swarm cluster
--swarm-addr addr to advertise for Swarm (default: detect and use the machine IP)
--swarm-discovery Discovery service to use with Swarm
--swarm-experimental Enable Swarm experimental features
--swarm-host "tcp://0.0.0.0:3376" ip/socket to listen on for Swarm master
--swarm-image "swarm:latest" Specify Docker image to use for Swarm [$MACHINE_SWARM_IMAGE]
--swarm-join-opt [--swarm-join-opt option --swarm-join-opt option] Define arbitrary flags for Swarm join
--swarm-master Configure Machine to be a Swarm master
--swarm-opt [--swarm-opt option --swarm-opt option] Define arbitrary flags for Swarm master
--swarm-strategy "spread" Define a default scheduling strategy for Swarm
--tls-san [--tls-san option --tls-san option] Support extra SANs for TLS certs
--virtualbox-boot2docker-url The URL of the boot2docker image. Defaults to the latest available version [$VIRTUALBOX_BOOT2DOCKER_URL]
--virtualbox-cpu-count "1" number of CPUs for the machine (-1 to use the number of CPUs available) [$VIRTUALBOX_CPU_COUNT]
--virtualbox-disk-size "20000" Size of disk for host in MB [$VIRTUALBOX_DISK_SIZE]
--virtualbox-host-dns-resolver Use the host DNS resolver [$VIRTUALBOX_HOST_DNS_RESOLVER]
--virtualbox-hostonly-cidr "192.168.99.1/24" Specify the Host Only CIDR [$VIRTUALBOX_HOSTONLY_CIDR]
--virtualbox-hostonly-nicpromisc "deny" Specify the Host Only Network Adapter Promiscuous Mode [$VIRTUALBOX_HOSTONLY_NIC_PROMISC]
--virtualbox-hostonly-nictype "82540EM" Specify the Host Only Network Adapter Type [$VIRTUALBOX_HOSTONLY_NIC_TYPE]
--virtualbox-hostonly-no-dhcp Disable the Host Only DHCP Server [$VIRTUALBOX_HOSTONLY_NO_DHCP]
--virtualbox-import-boot2docker-vm The name of a Boot2Docker VM to import [$VIRTUALBOX_BOOT2DOCKER_IMPORT_VM]
--virtualbox-memory "1024" Size of memory for host in MB [$VIRTUALBOX_MEMORY_SIZE]
--virtualbox-nat-nictype "82540EM" Specify the Network Adapter Type [$VIRTUALBOX_NAT_NICTYPE]
--virtualbox-no-dns-proxy Disable proxying all DNS requests to the host [$VIRTUALBOX_NO_DNS_PROXY]
--virtualbox-no-share Disable the mount of your home directory [$VIRTUALBOX_NO_SHARE]
--virtualbox-no-vtx-check Disable checking for the availability of hardware virtualization before the vm is started [$VIRTUALBOX_NO_VTX_CHECK]
--virtualbox-share-folder Mount the specified directory instead of the default home location. Format: dir:name [$VIRTUALBOX_SHARE_FOLDER]
--virtualbox-ui-type "headless" Specify the UI Type: (gui|sdl|headless|separate) [$VIRTUALBOX_UI_TYPE]

Créez maintenant 5 travailleurs - worker1 jusqu'à worker5 :

root@debian11:~# docker-machine create --driver virtualbox worker1
Running pre-create checks...
Creating machine...
(worker1) Copying /root/.docker/machine/cache/boot2docker.iso to /root/.docker/machine/machines/worker1/boot2docker.iso...
(worker1) Creating VirtualBox VM...
(worker1) Creating SSH key...
(worker1) Starting the VM...
(worker1) Check network to re-create if needed...
(worker1) Waiting for an IP...
Waiting for machine to be running, this may take a few minutes...
Detecting operating system of created instance...
Waiting for SSH to be available...
Detecting the provisioner...
Provisioning with boot2docker...
Copying certs to the local machine directory...
Copying certs to the remote machine...
Setting Docker configuration on the remote daemon...
Checking connection to Docker...
Docker is up and running!
To see how to connect your Docker Client to the Docker Engine running on this virtual machine, run: docker-machine env worker1

root@debian11:~# docker-machine create --driver virtualbox worker2
...
root@debian11:~# docker-machine create --driver virtualbox worker3
...
root@debian11:~# docker-machine create --driver virtualbox worker4
...
root@debian11:~# docker-machine create --driver virtualbox worker5
...

2.3 - Lister les VM Docker

Pour lister les VM Docker ainsi que leurs états, il convient d'utilise la sous-commande ls de la commande docker-machine :

root@debian11:~# docker-machine ls
NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS
manager1 - virtualbox Running tcp://192.168.99.100:2376 v19.03.12
worker1 - virtualbox Running tcp://192.168.99.101:2376 v19.03.12
worker2 - virtualbox Running tcp://192.168.99.102:2376 v19.03.12
worker3 - virtualbox Running tcp://192.168.99.103:2376 v19.03.12
worker4 - virtualbox Running tcp://192.168.99.104:2376 v19.03.12
worker5 - virtualbox Running tcp://192.168.99.105:2376 v19.03.12

2.4 - Obtenir l'adresse IP des VM

Une autre façon d'obtenir les adresses IP des VM est d'utiliser la sous-commande ip :

root@debian11:~# docker-machine ip manager1
192.168.99.100
root@debian11:~# docker-machine ip worker1
192.168.99.101
root@debian11:~# docker-machine ip worker2
192.168.99.102
root@debian11:~# docker-machine ip worker3
192.168.99.103
root@debian11:~# docker-machine ip worker4
192.168.99.104
root@debian11:~# docker-machine ip worker5
192.168.99.105

2.5 - Se connecter à une VM Docker

Pour se connecter à une VM Docker, il convient d'utiliser la sous-commande ssh de la commande docker-machine :

root@debian11:~# docker-machine ssh manager1
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@manager1:~$ exit
logout
root@debian11:~#

Important - Notez que la distribution de la VM est Boot2Docker. Cette distribution est basée sur Tiny Core Linux, s'exécute entièrement dans la mémoire vive, pèse 27 Mo et démarre en approximativement 5 secondes.

Installez maintenant le paquet mlocate :

root@debian11:~# apt install mlocate -y
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following packages were automatically installed and are no longer required:
libopengl0 linux-headers-5.10.0-15-amd64 linux-headers-5.10.0-15-common
Use 'apt autoremove' to remove them.
Suggested packages:
nocache
The following NEW packages will be installed:
mlocate
0 upgraded, 1 newly installed, 0 to remove and 16 not upgraded.
Need to get 98.3 kB of archives.
After this operation, 517 kB of additional disk space will be used.
Get:1 http://deb.debian.org/debian bullseye/main amd64 mlocate amd64 0.26-5 [98.3 kB]
Fetched 98.3 kB in 0s (1,985 kB/s)
Selecting previously unselected package mlocate.
(Reading database ... 166797 files and directories currently installed.)
Preparing to unpack .../mlocate_0.26-5_amd64.deb ...
Unpacking mlocate (0.26-5) ...
Setting up mlocate (0.26-5) ...
update-alternatives: using /usr/bin/mlocate to provide /usr/bin/locate (locate) in auto mode
Adding group `mlocate' (GID 123) ...
Done.
Created symlink /etc/systemd/system/timers.target.wants/mlocate.timer → /lib/systemd/system/mlocate.timer.
mlocate.service is a disabled or a static unit, not starting it.
Processing triggers for man-db (2.9.4-2) ...

Ayant été créées par root, les VM Docker ainsi que leurs fichiers associés sont stockés dans le répertoire /root/.docker/machine/machines/ :

root@debian11:~# updatedb
root@debian11:~# locate manager1
/root/.docker/machine/machines/manager1
/root/.docker/machine/machines/manager1/boot2docker.iso
/root/.docker/machine/machines/manager1/ca.pem
/root/.docker/machine/machines/manager1/cert.pem
/root/.docker/machine/machines/manager1/config.json
/root/.docker/machine/machines/manager1/disk.vmdk
/root/.docker/machine/machines/manager1/id_rsa
/root/.docker/machine/machines/manager1/id_rsa.pub
/root/.docker/machine/machines/manager1/key.pem
/root/.docker/machine/machines/manager1/manager1
/root/.docker/machine/machines/manager1/server-key.pem
/root/.docker/machine/machines/manager1/server.pem
/root/.docker/machine/machines/manager1/manager1/Logs
/root/.docker/machine/machines/manager1/manager1/manager1.vbox
/root/.docker/machine/machines/manager1/manager1/manager1.vbox-prev
/root/.docker/machine/machines/manager1/manager1/Logs/VBox.log

LAB #3 - Docker Swarm

3.1 - Présentation

Docker Swarm est un utilitaire qui permet de gérer un cluster pour déployer des conteneurs en permettant une imitation du comportement de docker sur une seule machine.

3.2 - Initialiser Docker Swarm

Pour initialiser Docker swarm, il convient d'utiliser la commande docker swarm init à partir de la VM Docker manager1 en stipulant l'adresse IP de manager1 :

root@debian11:~# docker-machine ssh manager1
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@manager1:~$ docker swarm init --advertise-addr 192.168.99.100
Swarm initialized: current node (y0war0lijmwhnexrfhfflulsd) is now a manager.
To add a worker to this swarm, run the following command:
docker swarm join --token SWMTKN-1-25tbmsyx452cuhpiedymuc8n9llo9jbjcbza93npdo35q1aaff-9teuxcpe09xw7v7xz1tnwpw4g 192.168.99.100:2377
To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

Notez que les ports suivants doivent être ouverts sur un nœud manager : 22/tcp, 2376/tcp, 2377/tcp, 7946/tcp, 7946/udp et 4789/udp.

3.3 - Le Statut Leader

Consultez le statut de la VM Docker manager1 :

docker@manager1:~$ docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION
y0war0lijmwhnexrfhfflulsd * manager1 Ready Active Leader 19.03.12

A un instant t il ne peut y avoir q'un seul Leader. Il est possible de créer d'autres nœuds de gestion en le rejoignant à swarm en utilisant le token prévu à cet effet. Par contre ces nœuds de gestion restent en attente d'une éventuelle défaillance du Leader actuel.

Pour connaître le token nécessaire pour rejoindre swarm en tant que nœud de gestion, saisissez la commande suivante :

docker@manager1:~$ docker swarm join-token manager
To add a manager to this swarm, run the following command:
docker swarm join --token SWMTKN-1-25tbmsyx452cuhpiedymuc8n9llo9jbjcbza93npdo35q1aaff-1teue04djnc4vu2eufzty59ys 192.168.99.100:2377

3.4 - Rejoindre le Swarm

Rejoignez les 5 machines travailleurs à swarm en utilisant le token worker :

docker@manager1:~$ exit
logout
root@debian11:~# docker-machine ssh worker1
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@worker1:~$ docker swarm join --token SWMTKN-1-25tbmsyx452cuhpiedymuc8n9llo9jbjcbza93npdo35q1aaff-9teuxcpe09xw7v7xz1tnwpw4g 192.168.99.100:2377
This node joined a swarm as a worker.
docker@worker1:~$ exit
logout
root@debian11:~# docker-machine ssh worker2
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@worker2:~$ docker swarm join --token SWMTKN-1-25tbmsyx452cuhpiedymuc8n9llo9jbjcbza93npdo35q1aaff-9teuxcpe09xw7v7xz1tnwpw4g 192.168.99.100:2377
This node joined a swarm as a worker.
docker@worker2:~$ exit
logout
root@debian11:~# docker-machine ssh worker3
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@worker3:~$ docker swarm join --token SWMTKN-1-25tbmsyx452cuhpiedymuc8n9llo9jbjcbza93npdo35q1aaff-9teuxcpe09xw7v7xz1tnwpw4g 192.168.99.100:2377
This node joined a swarm as a worker.
docker@worker3:~$ exit
logout
root@debian11:~# docker-machine ssh worker4
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@worker4:~$ docker swarm join --token SWMTKN-1-25tbmsyx452cuhpiedymuc8n9llo9jbjcbza93npdo35q1aaff-9teuxcpe09xw7v7xz1tnwpw4g 192.168.99.100:2377
This node joined a swarm as a worker.
docker@worker4:~$ exit
logout
root@debian11:~# docker-machine ssh worker5
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@worker5:~$ docker swarm join --token SWMTKN-1-25tbmsyx452cuhpiedymuc8n9llo9jbjcbza93npdo35q1aaff-9teuxcpe09xw7v7xz1tnwpw4g 192.168.99.100:2377
This node joined a swarm as a worker.
docker@worker5:~$ exit
logout
root@debian11:~#

Notez que les ports suivants doivent être ouverts sur un nœud worker : 22/tcp, 2376/tcp, 7946/tcp, 7946/udp et 4789/udp.

L'état des VM Docker peut être consulter en utilisant de nouveau la commande docker node ls :

root@debian11:~# docker-machine ssh manager1
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@manager1:~$ docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION
y0war0lijmwhnexrfhfflulsd * manager1 Ready Active Leader 19.03.12
v5ai62lmhfsdcauccqmjyu6qk worker1 Ready Active 19.03.12
j4mr3d2ji30t7hu0trob5dpgz worker2 Ready Active 19.03.12
pouo7nuvirq0qkuvvrp04a47h worker3 Ready Active 19.03.12
mo0dd5ech6ifdgd8pa6cjz896 worker4 Ready Active 19.03.12
5am2vd39pybytu1nd3oooabtq worker5 Ready Active 19.03.12

Notez que vous ne pouvez pas utiliser cette commande à partir d'un travailleur :

docker@manager1:~$ exit
logout
root@debian11:~# docker-machine ssh worker5
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@worker5:~$ docker node ls
Error response from daemon: This node is not a swarm manager. Worker nodes can't be used to view or modify cluster state. Please run this command on a manager node or promote the current node to a manager.
docker@worker5:~$ exit
logout
exit status 1
root@debian11:~#

3.5 - Consulter les Informations de Swarm

Il est possible de visualiser les informations concernant le swarm en utilisant la commande docker info :

root@debian11:~# docker-machine ssh manager1
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@manager1:~$ docker info
Client:
Debug Mode: false
Server:
Containers: 0
Running: 0
Paused: 0
Stopped: 0
Images: 0
Server Version: 19.03.12
Storage Driver: overlay2
Backing Filesystem: extfs
Supports d_type: true
Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
Volume: local
Network: bridge host ipvlan macvlan null overlay
Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: active
NodeID: y0war0lijmwhnexrfhfflulsd
Is Manager: true
ClusterID: w3mq6i01k4siboyqv3w3nbyu7
Managers: 1
Nodes: 6
Default Address Pool: 10.0.0.0/8
SubnetSize: 24
Data Path Port: 4789
Orchestration:
Task History Retention Limit: 5
Raft:
Snapshot Interval: 10000
Number of Old Snapshots to Retain: 0
Heartbeat Tick: 1
Election Tick: 10
Dispatcher:
Heartbeat Period: 5 seconds
CA Configuration:
Expiry Duration: 3 months
Force Rotate: 0
Autolock Managers: false
Root Rotation In Progress: false
Node Address: 192.168.99.100
Manager Addresses:
192.168.99.100:2377
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 7ad184331fa3e55e52b890ea95e65ba581ae3429
runc version: dc9208a3303feef5b3839f4323d9beb36df0a9dd
init version: fec3683
Security Options:
seccomp
Profile: default
Kernel Version: 4.19.130-boot2docker
Operating System: Boot2Docker 19.03.12 (TCL 10.1)
OSType: linux
Architecture: x86_64
CPUs: 1
Total Memory: 985.4MiB
Name: manager1
ID: UIL3:SNFZ:J2XE:4QVD:7XYM:MPB7:2LHC:NMY7:B4CU:QMUK:3A66:H3G6
Docker Root Dir: /mnt/sda1/var/lib/docker
Debug Mode: false
Registry: https://index.docker.io/v1/
Labels:
provider=virtualbox
Experimental: false
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false
Product License: Community Engine

Important - Quand le moteur Docker est en mode swarm, les noeuds de gestion implémentent le Raft Consensus Algorithm pour gérer l'état du cluster.

3.6 - Démarrer un Service

Dans cet exemple, nous allons démarrer le service nginx avec les propriétés suivantes :

Mappage du port nginx sur le port 80 de la machine hôte,

5 instances du service,

Un nom unique de web.

docker@manager1:~$ docker service create --replicas 5 -p 80:80 --name web nginx
oree977o1unlk5ndos0y44i2h
overall progress: 5 out of 5 tasks
1/5: running [==================================================>]
2/5: running [==================================================>]
3/5: running [==================================================>]
4/5: running [==================================================>]
5/5: running [==================================================>]
verify: Service converged

Pour consulter l'état de ce service, utilisez la commande docker service ls :

docker@manager1:~$ docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
oree977o1unl web replicated 5/5 nginx:latest *:80->80/tcp

Ce service fonctionne dans des conteneurs Docker :

docker@manager1:~$ docker service ps web
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
son0vgc73drb web.1 nginx:latest worker4 Running Running 48 seconds ago
ojqyweuo65jw web.2 nginx:latest worker5 Running Running 49 seconds ago
mb40onnaxd0u web.3 nginx:latest manager1 Running Running 49 seconds ago
4vwsho5x7i36 web.4 nginx:latest worker2 Running Running 49 seconds ago
sk9hr6j2u47c web.5 nginx:latest worker3 Running Running 50 seconds ago

Important - Notez qu'il n'y a pas de conteneur sur worker1.

Pour constater le lancement du daemon nginx, lancez la commande docker ps sur la machine manager1 :

docker@manager1:~$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
244fecd46312 nginx:latest "/docker-entrypoint.…" About a minute ago Up About a minute 80/tcp web.3.mb40onnaxd0u8t0nhbzx9rdih

Par contre la même commande exécutée sur worker1 donne le résultat suivant :

docker@manager1:~$ exit
logout
root@debian11:~# docker-machine ssh worker1
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@worker1:~$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
docker@worker1:~$ exit
logout
root@debian11:~#

Connectez-vous sur chaque VM Docker pour constater que le service nginx fonctionne :

root@debian11:~# docker-machine ssh manager1
( '>')
/) TC (\ Core is distributed with ABSOLUTELY NO WARRANTY.
(/-_--_-\) www.tinycorelinux.net
docker@manager1:~$ curl 192.168.99.100
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
docker@manager1:~$ curl 192.168.99.101
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
docker@manager1:~$ curl 192.168.99.102
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
docker@manager1:~$ curl 192.168.99.103
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
docker@manager1:~$ curl 192.168.99.104
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
docker@manager1:~$ curl 192.168.99.105
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>

Important - Notez que le service est même disponible en consultant l'adresse IP de worker1.

3.7 - Augmentation et Réduction du Service

Actuellement, il existe 5 conteneurs en cours d'exécution. Pour procéder à un scale-up à 8 conteneurs, il convient d'utiliser la commande docker service scale :

docker@manager1:~$ docker service scale web=8
web scaled to 8
overall progress: 8 out of 8 tasks
1/8: running [==================================================>]
2/8: running [==================================================>]
3/8: running [==================================================>]
4/8: running [==================================================>]
5/8: running [==================================================>]
6/8: running [==================================================>]
7/8: running [==================================================>]
8/8: running [==================================================>]
verify: Service converged

Notez que la commande docker service ls confirme le fait qu'il y a 8 replicas :

docker@manager1:~$ docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
oree977o1unl web replicated 8/8 nginx:latest *:80->80/tcp

Des trois replicas supplémentaires, deux ont été lancés sur worker5 tandis que le troisième a été lancé sur worker1 :

docker@manager1:~$ docker service ps web
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
son0vgc73drb web.1 nginx:latest worker4 Running Running 9 minutes ago
ojqyweuo65jw web.2 nginx:latest worker5 Running Running 9 minutes ago
mb40onnaxd0u web.3 nginx:latest manager1 Running Running 9 minutes ago
4vwsho5x7i36 web.4 nginx:latest worker2 Running Running 9 minutes ago
sk9hr6j2u47c web.5 nginx:latest worker3 Running Running 9 minutes ago
pui4dnkepu27 web.6 nginx:latest worker1 Running Running about a minute ago
yj0kexdcuo5u web.7 nginx:latest worker5 Running Running about a minute ago
93jtbxqj2dyz web.8 nginx:latest worker1 Running Running about a minute ago

3.8 - Consulter le Statut d'un Noeud

Pour se renseigner sur le statut du nœud courant, il convient d'utiliser la commande docker node inspect avec le mot clef self :

docker@manager1:~$ docker node inspect self
[
{
"ID": "y0war0lijmwhnexrfhfflulsd",
"Version": {
"Index": 9
},
"CreatedAt": "2023-12-16T13:38:18.600836601Z",
"UpdatedAt": "2023-12-16T13:38:19.126257379Z",
"Spec": {
"Labels": {},
"Role": "manager",
"Availability": "active"
},
"Description": {
"Hostname": "manager1",
"Platform": {
"Architecture": "x86_64",
"OS": "linux"
},
"Resources": {
"NanoCPUs": 1000000000,
"MemoryBytes": 1033252864
},
"Engine": {
"EngineVersion": "19.03.12",
"Labels": {
"provider": "virtualbox"
},
"Plugins": [
{
"Type": "Log",
"Name": "awslogs"
},
{
"Type": "Log",
"Name": "fluentd"
},
{
"Type": "Log",
"Name": "gcplogs"
},
{
"Type": "Log",
"Name": "gelf"
},
{
"Type": "Log",
"Name": "journald"
},
{
"Type": "Log",
"Name": "json-file"
},
{
"Type": "Log",
"Name": "local"
},
{
"Type": "Log",
"Name": "logentries"
},
{
"Type": "Log",
"Name": "splunk"
},
{
"Type": "Log",
"Name": "syslog"
},
{
"Type": "Network",
"Name": "bridge"
},
{
"Type": "Network",
"Name": "host"
},
{
"Type": "Network",
"Name": "ipvlan"
},
{
"Type": "Network",
"Name": "macvlan"
},
{
"Type": "Network",
"Name": "null"
},
{
"Type": "Network",
"Name": "overlay"
},
{
"Type": "Volume",
"Name": "local"
}
]
},
"TLSInfo": {
"TrustRoot": "-----BEGIN CERTIFICATE-----\nMIIBazCCARCgAwIBAgIUbi2tpJHqoqK+BA/p9c+Y9AmtQSAwCgYIKoZIzj0EAwIw\nEzERMA8GA1UEAxMIc3dhcm0tY2EwHhcNMjMxMjE2MTMzMzAwWhcNNDMxMjExMTMz\nMzAwWjATMREwDwYDVQQDEwhzd2FybS1jYTBZMBMGByqGSM49AgEGCCqGSM49AwEH\nA0IABKuD7Svum+bER9CszNtFt7ASMr5gj6Vea0oM7SCrlyYMCn8ryaHXQ9J+iEIh\nfWrpKmjNtei3/j+leOVF0flpg2OjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNVHRMB\nAf8EBTADAQH/MB0GA1UdDgQWBBRqlCTTUy9JODtzaVecgmjID/M5kzAKBggqhkjO\nPQQDAgNJADBGAiEA06sGunqGwd23lyjcUoczMWGQGln9nv0pmm/riJQvB80CIQC9\nvXNZUbC6U5lSQ7eGhfmmHi1JAfb88wGau0AlreBczw==\n-----END CERTIFICATE-----\n",
"CertIssuerSubject": "MBMxETAPBgNVBAMTCHN3YXJtLWNh",
"CertIssuerPublicKey": "MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEq4PtK+6b5sRH0KzM20W3sBIyvmCPpV5rSgztIKuXJgwKfyvJoddD0n6IQiF9aukqaM216Lf+P6V45UXR+WmDYw=="
}
},
"Status": {
"State": "ready",
"Addr": "192.168.99.100"
},
"ManagerStatus": {
"Leader": true,
"Reachability": "reachable",
"Addr": "192.168.99.100:2377"
}
}
]

Pour se renseigner sur le statut d'un autre nœud, il convient d'utiliser la commande docker node inspect avec le nom du nœud concerné :

docker@manager1:~$ docker node inspect worker1
[
{
"ID": "v5ai62lmhfsdcauccqmjyu6qk",
"Version": {
"Index": 15
},
"CreatedAt": "2023-12-16T13:40:08.301827885Z",
"UpdatedAt": "2023-12-16T13:40:08.453463845Z",
"Spec": {
"Labels": {},
"Role": "worker",
"Availability": "active"
},
"Description": {
"Hostname": "worker1",
"Platform": {
"Architecture": "x86_64",
"OS": "linux"
},
"Resources": {
"NanoCPUs": 1000000000,
"MemoryBytes": 1033252864
},
"Engine": {
"EngineVersion": "19.03.12",
"Labels": {
"provider": "virtualbox"
},
"Plugins": [
{
"Type": "Log",
"Name": "awslogs"
},
{
"Type": "Log",
"Name": "fluentd"
},
{
"Type": "Log",
"Name": "gcplogs"
},
{
"Type": "Log",
"Name": "gelf"
},
{
"Type": "Log",
"Name": "journald"
},
{
"Type": "Log",
"Name": "json-file"
},
{
"Type": "Log",
"Name": "local"
},
{
"Type": "Log",
"Name": "logentries"
},
{
"Type": "Log",
"Name": "splunk"
},
{
"Type": "Log",
"Name": "syslog"
},
{
"Type": "Network",
"Name": "bridge"
},
{
"Type": "Network",
"Name": "host"
},
{
"Type": "Network",
"Name": "ipvlan"
},
{
"Type": "Network",
"Name": "macvlan"
},
{
"Type": "Network",
"Name": "null"
},
{
"Type": "Network",
"Name": "overlay"
},
{
"Type": "Volume",
"Name": "local"
}
]
},
"TLSInfo": {
"TrustRoot": "-----BEGIN CERTIFICATE-----\nMIIBazCCARCgAwIBAgIUbi2tpJHqoqK+BA/p9c+Y9AmtQSAwCgYIKoZIzj0EAwIw\nEzERMA8GA1UEAxMIc3dhcm0tY2EwHhcNMjMxMjE2MTMzMzAwWhcNNDMxMjExMTMz\nMzAwWjATMREwDwYDVQQDEwhzd2FybS1jYTBZMBMGByqGSM49AgEGCCqGSM49AwEH\nA0IABKuD7Svum+bER9CszNtFt7ASMr5gj6Vea0oM7SCrlyYMCn8ryaHXQ9J+iEIh\nfWrpKmjNtei3/j+leOVF0flpg2OjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNVHRMB\nAf8EBTADAQH/MB0GA1UdDgQWBBRqlCTTUy9JODtzaVecgmjID/M5kzAKBggqhkjO\nPQQDAgNJADBGAiEA06sGunqGwd23lyjcUoczMWGQGln9nv0pmm/riJQvB80CIQC9\nvXNZUbC6U5lSQ7eGhfmmHi1JAfb88wGau0AlreBczw==\n-----END CERTIFICATE-----\n",
"CertIssuerSubject": "MBMxETAPBgNVBAMTCHN3YXJtLWNh",
"CertIssuerPublicKey": "MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEq4PtK+6b5sRH0KzM20W3sBIyvmCPpV5rSgztIKuXJgwKfyvJoddD0n6IQiF9aukqaM216Lf+P6V45UXR+WmDYw=="
}
},
"Status": {
"State": "ready",
"Addr": "192.168.99.101"
}
}
]

L'option –pretty produit une sortie plus facilement lisible :

docker@manager1:/$ docker node inspect --pretty worker1
ID:	1f5qtolgtonqmhjk5ppwc8x1b
Hostname:	worker1
Joined at:	2017-09-08 11:48:42.011596185 +0000 utc
Status:
State:	Ready
Availability:	Active
Address:	192.168.99.101
Platform:
Operating System:	linux
Architecture:	x86_64
Resources:
CPUs:	1
Memory:	995.8MiB
Plugins:
Log:	awslogs, fluentd, gcplogs, gelf, journald, json-file, logentries, splunk, syslog
Network:	bridge, host, macvlan, null, overlay
Volume:	local
Engine Version:	17.06.2-ce
Engine Labels:
- provider=virtualbox
TLS Info:
TrustRoot:
-----BEGIN CERTIFICATE-----
MIIBajCCARCgAwIBAgIUNuU4I89kxId2QXulofRKxJa9XRcwCgYIKoZIzj0EAwIw
EzERMA8GA1UEAxMIc3dhcm0tY2EwHhcNMTcwOTA4MTEzOTAwWhcNMzcwOTAzMTEz
OTAwWjATMREwDwYDVQQDEwhzd2FybS1jYTBZMBMGByqGSM49AgEGCCqGSM49AwEH
A0IABEqgLUbyjyNuP35aAzW+aqVB8AkghvpF5hq1KnMveHbl4Ilr+EyDjlYZkbnt
Gb/xmsy/tOP8uz598ZX/JlR4fZyjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNVHRMB
Af8EBTADAQH/MB0GA1UdDgQWBBSzoKGrN0ELfEIMsjxuYj5LAckD2jAKBggqhkjO
PQQDAgNIADBFAiB34DOvDtIYjJ+GzbPMGu9Dd/cJGvy7CJg1tNUG3SoOrAIhAJZ4
TJBucTomFSDsj5Y/R6TfhcpXpsksk7JwYgEglu44
-----END CERTIFICATE-----
Issuer Subject:	MBMxETAPBgNVBAMTCHN3YXJtLWNh
Issuer Public Key:	MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAESqAtRvKPI24/floDNb5qpUHwCSCG+kXmGrUqcy94duXgiWv4TIOOVhmRue0Zv/GazL+04/y7Pn3xlf8mVHh9nA==

3.9 - Haute Disponibilité

Quand un nœud est actif, il est capable de recevoir de nouvelles tâches à partir du manager :

pendant un scale-up,

pendant une une mise à jour progressive,

quand un autre nœud reçois une instruction de se mettre en indisponibilité,

quand un service se mets en échec sur un autre nœud

Rappelez-vous que la swarm contient 6 VM Docker :

docker@manager1:~$ docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ENGINE VERSION
y0war0lijmwhnexrfhfflulsd * manager1 Ready Active Leader 19.03.12
v5ai62lmhfsdcauccqmjyu6qk worker1 Ready Active 19.03.12
j4mr3d2ji30t7hu0trob5dpgz worker2 Ready Active 19.03.12
pouo7nuvirq0qkuvvrp04a47h worker3 Ready Active 19.03.12
mo0dd5ech6ifdgd8pa6cjz896 worker4 Ready Active 19.03.12
5am2vd39pybytu1nd3oooabtq worker5 Ready Active 19.03.12

et que sur les 6 VM Docker, il y a 8 conteneurs,

docker@manager1:~$ docker service ps web
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
son0vgc73drb web.1 nginx:latest worker4 Running Running 12 minutes ago
ojqyweuo65jw web.2 nginx:latest worker5 Running Running 12 minutes ago
mb40onnaxd0u web.3 nginx:latest manager1 Running Running 12 minutes ago
4vwsho5x7i36 web.4 nginx:latest worker2 Running Running 12 minutes ago
sk9hr6j2u47c web.5 nginx:latest worker3 Running Running 12 minutes ago
pui4dnkepu27 web.6 nginx:latest worker1 Running Running 4 minutes ago
yj0kexdcuo5u web.7 nginx:latest worker5 Running Running 4 minutes ago
93jtbxqj2dyz web.8 nginx:latest worker1 Running Running 4 minutes ago

dont deux se trouvent sur worker1 :

docker@manager1:~$ docker node ps worker1
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
pui4dnkepu27 web.6 nginx:latest worker1 Running Running 4 minutes ago
93jtbxqj2dyz web.8 nginx:latest worker1 Running Running 4 minutes ago

Mettez worker1 en mode d'indisponibilité en utilisant l'option –availability drain :

docker@manager1:~$ docker node update --availability drain worker1
worker1

Constatez que le service web a été déplacé sur deux autres noeuds, manager1 et worker4 :

docker@manager1:~$ docker service ps web
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
son0vgc73drb web.1 nginx:latest worker4 Running Running 14 minutes ago
ojqyweuo65jw web.2 nginx:latest worker5 Running Running 14 minutes ago
mb40onnaxd0u web.3 nginx:latest manager1 Running Running 14 minutes ago
4vwsho5x7i36 web.4 nginx:latest worker2 Running Running 14 minutes ago
sk9hr6j2u47c web.5 nginx:latest worker3 Running Running 14 minutes ago
ag41oh489h4t web.6 nginx:latest manager1 Running Running 3 seconds ago
pui4dnkepu27 \_ web.6 nginx:latest worker1 Shutdown Shutdown 4 seconds ago
yj0kexdcuo5u web.7 nginx:latest worker5 Running Running 5 minutes ago
kv7ax6cwzpkf web.8 nginx:latest worker2 Running Running 3 seconds ago
93jtbxqj2dyz \_ web.8 nginx:latest worker1 Shutdown Shutdown 4 seconds ago

3.10 - Supprimer un Service

Pour supprimer un service il convient d'utiliser la commande docker service rm

docker@manager1:~$ docker service rm web
web
docker@manager1:~$ docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
docker@manager1:~$ docker service inspect web
[]
Status: Error: no such service: web, Code: 1

3.11 - Sauvegarder Docker Swarm

La configuration de Docker Swarm est contenue dans le répertoire /var/lib/docker/swarm de chaque Manager dans le Swarm :

docker@manager1:~$ sudo su -
root@manager1:~# ls -l /var/lib/docker/swarm
total 20
drwxr-xr-x 2 root root 4096 Dec 16 13:38 certificates
-rw------- 1 root root 215 Dec 16 13:38 docker-state.json
drwx------ 4 root root 4096 Dec 16 13:38 raft
-rw------- 1 root root 70 Dec 16 13:38 state.json
drwxr-xr-x 2 root root 4096 Dec 16 13:38 worker

Le processus de sauvegarde necéssite qu'il y ait au moins deux Managers dans le Swarm. Le procédure de sauvegarde est :

arrêt du service Docker sur le Manager à sauvegarder,

sauvegarde du répertoire /var/lib/docker/swarm,

redémarrage du service Docker sur le Manager concerné.

3.12 - Restaurer Docker Swarm

Le procédure de resturation est :

arrêt du service Docker sur un nouveau Manager,

suppression du contenu du répertoire /var/lib/docker/swarm dans le nouveau Manager,

restauration du répertoire /var/lib/docker/swarm dans le nouveau Manager à partir de la sauvegarde,

exécution de la commande docker swarm init –force-new-cluster sur le nouveau Manager,

ajout des Managers et Workers à Swarm.

Copyright © 2024 Hugh Norris.