Docker Network - Host Driver e Add Host

Destruir a stack atual:

~/compose$ docker compose down
[+] Running 2/2
 ✔ Container compose-postgre-1   Removed                                        0.5s
 ✔ Container compose-kubenews-1  Removed                                       10.5s

Host Driver

Criação de um novo arquivo nomeado host-compose.yaml:

~/compose$ touch host-compose.yaml
~/compose$ ls
compose.yaml  host-compose.yaml

Edição do arquivo host-compose.yaml:

~/compose$ vim host-compose.yaml

services:
  nginx:
    image: nginx

Subida do Docker Compose:

~/compose$ docker compose up -d
[+] Running 2/2
 ✔ Container compose-postgre-1   Started                                        0.5s
 ✔ Container compose-kubenews-1  Started                                        0.5s

Neste caso foi utilizado o arquivo compose.yaml utilizado anterioemente. Não foi considerado o arquivo host-compose.yaml.

Baixar o Docker Compose:

~/compose$ docker compose down
[+] Running 2/2
 ✔ Container compose-kubenews-1  Removed                                       10.5s
 ✔ Container compose-postgre-1   Removed                                        0.4s

Para considerar o arquivo host-compose.yaml deve ser acrescentada a opção "-f host-compose.yaml":

~/compose$ docker compose -f host-compose.yaml up -d
[+] Running 0/0
 ⠋ Network compose_default  Creating                                            0.1s
WARN[0000] Found orphan containers ([compose-postgre-1 compose-kubenews-1]) for this [+] Running 2/2 removed or renamed this service in your compose file, you can run thi
 ✔ Network compose_default    Created                                           0.1s
 ✔ Container compose-nginx-1  Started                                           0.4s

Container em execução

~/compose$ docker container ls
CONTAINER ID   IMAGE     COMMAND                  CREATED              STATUS              PORTS     NAMES
0fae888555c1   nginx     "/docker-entrypoint.…"   About a minute ago   Up About a minute   80/tcp    compose-nginx-1

Inspeção do container onde é possível verificar a utilização da rede bridge:

~/compose$ docker container inspect 0fae888555c1 | grep -Ei -C 5
 "bridge"
                "maintainer": "NGINX Docker Maintainers <[e-mail]>"
            },
            "StopSignal": "SIGQUIT"
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "2923efdb95b0756f14791dbacbb9ab39df1840e12222c29d3d1e32fcf259cc28",
            "SandboxKey": "/var/run/docker/netns/2923efdb95b0",
            "Ports": {
                "80/tcp": null
            },

Para conexão à rede host, faz-se necessário editar o arquivo host-compose.yaml para especificar "network_mode: host":

services:
  nginx:
    image: nginx
    network_mode: "host"

Subir novamente o Docker Compose e inspecionar o container:

~/compose$ docker compose -f host-compose.yaml up -d
[+] Running 1/1
 ✔ Container compose-nginx-1  Started                                           0.7s

~/compose$ docker container ls
CONTAINER ID   IMAGE     COMMAND                  CREATED         STATUS         PORTS     NAMES
f8b3a9e406bd   nginx     "/docker-entrypoint.…"   5 seconds ago   Up 4 seconds             compose-nginx-1

~/compose$ docker container inspect f8b3a9e406bd | grep -Ei -C 5 "network"

            "NetworkMode": "host",

--

            "Networks": {
                "host": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": null,
                    "MacAddress": "",
                    "DriverOpts": null,
                    "NetworkID": "73f2d51a39deaf42b3cfa89bd34602ed8fc2bfac806112c047b3749fd2e4721e",
                    "EndpointID": "ebdfcbdc3ca04d0389cca5491d572d3f827d40cf38339d9e2af2de29676da961",
                    "Gateway": "",
                    "IPAddress": "",

Recuperar o IP da máquina:

~/compose$ ifconfig eth0
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.43.217  netmask 255.255.240.0  broadcast 192.168.47.255
        inet6 fe80::215:5dff:fe0c:31f2  prefixlen 64  scopeid 0x20<link>
        ether 00:15:5d:0c:31:f2  txqueuelen 1000  (Ethernet)
        RX packets 4331  bytes 1433458 (1.4 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 214  bytes 60343 (60.3 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Add Host

Adição de um novo container curl:

~/compose$ vim host-compose.yaml

services:
  nginx:
    image: nginx
    network_mode: "host"
  curl:
    image: nginx

Subida do Docker Compose:

~/compose$ docker compose -f host-compose.yaml up -d
[+] Running 2/2
 ✔ Container compose-nginx-1  Running                                           0.0s
 ✔ Container compose-curl-1   Started                                           0.3s

O container foi criado:

~/compose$ docker container ls
CONTAINER ID   IMAGE     COMMAND                  CREATED          STATUS          PORTS     NAMES
65d5d33114aa   nginx     "/docker-entrypoint.…"   31 seconds ago   Up 31 seconds   80/tcp    compose-curl-1
f8b3a9e406bd   nginx     "/docker-entrypoint.…"   6 minutes ago    Up 6 minutes              compose-nginx-1

Entrando nos containers em modo interativo é possível verificar a linha de entrada do host na bridge:

~/compose$ docker container exec -it compose-nginx-1 /bin/bash
root@Latitude5440:/# 

~/compose$ docker container exec -it compose-curl-1 /bin/bash
root@65d5d33114aa:/#

Destaque para:

root@Latitude5440:/# exit
root@65d5d33114aa:/#

Recuperar o IP da interface eth0 da máquina:

$ ifconfig eth0
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.43.217  netmask 255.255.240.0  broadcast 192.168.47.255
        inet6 fe80::215:5dff:fe0c:31f2  prefixlen 64  scopeid 0x20<link>
        ether 00:15:5d:0c:31:f2  txqueuelen 1000  (Ethernet)
        RX packets 5051  bytes 1638027 (1.6 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 229  bytes 62962 (62.9 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Ainda no modo interativo do container compose-curl-1 é possível acessar o container compose-nginx-1:

root@65d5d33114aa:/# curl http://192.168.43.217
<!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>

Domínios

Edição do arquivo host-compose.yaml para adicionar "extra_hosts" sem a necessidade de editar o arquivo "/etc/hosts":

~/compose$ vim host-compose.yaml

services:
  nginx:
    image: nginx
    network_mode: "host"
  curl:
    image: nginx
    extra_hosts:
      docker.barbieri.com: "192.168.43.217"

Subida do Docker Compose:

~/compose$ docker compose -f host-compose.yaml up -d
[+] Running 2/2
 ✔ Container compose-curl-1   Started                                           0.8s
 ✔ Container compose-nginx-1  Running                                           0.0s

Lista os containers:

~/compose$ docker container ls
CONTAINER ID   IMAGE     COMMAND                  CREATED          STATUS          PORTS     NAMES
d46d7fd09b26   nginx     "/docker-entrypoint.…"   29 seconds ago   Up 27 seconds   80/tcp    compose-curl-1
f8b3a9e406bd   nginx     "/docker-entrypoint.…"   19 minutes ago   Up 19 minutes             compose-nginx-1

Entrar no modo interativo novamente e o acesso ao domínio:

~/compose$ docker container exec -it compose-curl-1 /bin/bash
root@d46d7fd09b26:/# curl http://docker.barbieri.com
<!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>