Docker Stack, el docker-compose para Swarm

  Las bondades que nos proporciona docker-compose se pueden aplicar al swarm. Esto es, la configuración de los servicios por medio de archivos de configuración. Utilizaremos el ejemplo del lab anterior donde tenemos un swarm con un vizualizador y un web simple nginx.

el archivo viz.yml

version: "3.1"

services:
  viz:
    image: dockersamples/visualizer
    ports:
      - 8080:8080
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    deploy:
      placement:
        constraints: [node.role == manager ]

el archivo web.yml

version: "3.1"

services:
    web1:
        image: nginx
        ports:
          - 8081:80
    web2:
        image: httpd
        ports:
          - 8082:80
    web3:
        image: httpd
        ports:
          - 8083:80

Ahora vamos a terminar los servicios viz y web. primero antes de deployarlos en el nuevo stack.

bext@bext-VPCF13WFX:~$ docker stack deploy -c viz.yml viz
Creating network viz_default
Creating service viz_viz
failed to create service viz_viz: Error response from daemon: rpc error: code = InvalidArgument desc = port '8080' is already in use by service 'viz' (1k6akx8sh6yrod7zsi5cvf71a) as an ingress port
bext@bext-VPCF13WFX:~$ docker service ls
ID                  NAME                MODE                REPLICAS            IMAGE                             PORTS
1k6akx8sh6yr        viz                 replicated          1/1                 dockersamples/visualizer:latest   *:8080->8080/tcp
vtuogblw02ak        web                 replicated          2/2                 nginx:latest                      *:80->80/tcp
bext@bext-VPCF13WFX:~$ docker service rm viz
viz
bext@bext-VPCF13WFX:~$ docker service ls
ID                  NAME                MODE                REPLICAS            IMAGE               PORTS
vtuogblw02ak        web                 replicated          2/2                 nginx:latest        *:80->80/tcp
bext@bext-VPCF13WFX:~$ docker stack deploy -c viz.yml viz
Creating service viz_viz
bext@bext-VPCF13WFX:~$ nano web.yml
bext@bext-VPCF13WFX:~$ docker service rm web
web
bext@bext-VPCF13WFX:~$ docker stack deploy -c web.yml web
Creating network web_default
Creating service web_web2
Creating service web_web3
Creating service web_web1
bext@bext-VPCF13WFX:~$ docker service ls
ID                  NAME                MODE                REPLICAS            IMAGE                             PORTS
uu15oc0t9mc6        viz_viz             replicated          1/1                 dockersamples/visualizer:latest   *:8080->8080/tcp
aszigymy7adn        web_web1            replicated          1/1                 nginx:latest                      *:8081->80/tcp
pqb4wultub03        web_web2            replicated          1/1                 httpd:latest                      *:8082->80/tcp
qpx5b2wyge0d        web_web3            replicated          1/1                 httpd:latest                      *:8083->80/tcp

bext@bext-VPCF13WFX:~$ docker stack ps web
ID                  NAME                IMAGE               NODE                DESIRED STATE       CURRENT STATE            ERROR               PORTS
y61pa7cwj5oa        web_web1.1          nginx:latest        sw-master           Running             Running 40 seconds ago                       
wd0fh80ckwpj        web_web3.1          httpd:latest        sw-worker-2         Running             Running 22 seconds ago                       
zr1uwvrbdw6p        web_web2.1          httpd:latest        sw-worker-1         Running             Running 21 seconds ago                       

Modificamos el web.yml para redeployarlo.
webv2.yml

version: "3.1"

services:
    web1:
        image: nginx
        ports:
          - 8081:80
        deploy:
            replicas: 3
    web2:
        image: httpd
        ports:
          - 8082:80
        deploy:
           replicas: 2

bext@bext-VPCF13WFX:~$ docker stack deploy -c webv2.yml web
Updating service web_web1 (id: aszigymy7adnix8q5lrhj9v1y)
Updating service web_web2 (id: pqb4wultub03vakv0ym2z41c7)
bext@bext-VPCF13WFX:~$ docker container ls
CONTAINER ID        IMAGE                             COMMAND                  CREATED             STATUS                    PORTS               NAMES
171572f3eff1        nginx:latest                      "nginx -g 'daemon of…"   9 minutes ago       Up 9 minutes              80/tcp              web_web1.1.y61pa7cwj5oai3cocmhf686vb
3e340e21423e        dockersamples/visualizer:latest   "npm start"              14 minutes ago      Up 14 minutes (healthy)   8080/tcp            viz_viz.1.zq62g7exoqfpgj8efqy4h76cd
bext@bext-VPCF13WFX:~$ docker service ls
ID                  NAME                MODE                REPLICAS            IMAGE                             PORTS
uu15oc0t9mc6        viz_viz             replicated          1/1                 dockersamples/visualizer:latest   *:8080->8080/tcp
aszigymy7adn        web_web1            replicated          3/3                 nginx:latest                      *:8081->80/tcp
pqb4wultub03        web_web2            replicated          2/2                 httpd:latest                      *:8082->80/tcp
qpx5b2wyge0d        web_web3            replicated          1/1                 httpd:latest                      *:8083->80/tcp
bext@bext-VPCF13WFX:~$ docker service rm web_web_3
Error: No such service: web_web_3
bext@bext-VPCF13WFX:~$ docker service rm qpx5b2wyge0d
qpx5b2wyge0d
bext@bext-VPCF13WFX:~$ docker service ls
ID                  NAME                MODE                REPLICAS            IMAGE                             PORTS
uu15oc0t9mc6        viz_viz             replicated          1/1                 dockersamples/visualizer:latest   *:8080->8080/tcp
aszigymy7adn        web_web1            replicated          3/3                 nginx:latest                      *:8081->80/tcp
pqb4wultub03        web_web2            replicated          2/2                 httpd:latest                      *:8082->80/tcp

eot.