Como Alterar o Caminho do Arquivo Docker.sock
Você está interessado em saber como modificar a localização do arquivo docker.sock? Este artigo detalha o processo.
O Que é o Docker Socket?
O arquivo de soquete do Docker, geralmente encontrado em /var/run/docker.sock, é fundamental para a comunicação com o daemon principal do Docker. Ele serve como o ponto de acesso para a API do Docker e é utilizado pela interface de linha de comando (CLI) do Docker para executar comandos. Essencialmente, é a ponte que permite a interação entre diferentes componentes do Docker.
A seguir, vamos explorar os passos necessários para alterar o caminho padrão deste arquivo.
Desativando o Serviço Docker
Inicialmente, é crucial interromper o serviço Docker, caso esteja em execução. Para verificar se o serviço foi devidamente interrompido, execute o comando de status.
[email protected]:~$ sudo service docker stop
[email protected]:~$ sudo service docker status
● docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: inactive (dead) since Sat 2019-11-23 15:37:00 EST; 4s ago
Docs: https://docs.docker.com
Process: 1474 ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock (code=exited, status=0/SUCCESS)
Main PID: 1474 (code=exited, status=0/SUCCESS)
Nov 10 01:56:49 etechpt.com dockerd[1474]: time="2019-11-10T01:56:49-05:00" level=error msg="2019/11/10 06:56:49 Entering go-plugins-helper
Nov 10 01:56:49 etechpt.com dockerd[1474]: time="2019-11-10T01:56:49-05:00" level=error msg="time="2019-11-10T06:56:49Z" level=debug msg=
Nov 10 01:56:49 etechpt.com dockerd[1474]: time="2019-11-10T01:56:49-05:00" level=error msg="time="2019-11-10T06:56:49Z" level=error msg=
Nov 10 01:57:23 etechpt.com dockerd[1474]: time="2019-11-10T01:57:23.635519865-05:00" level=info msg="Container 3141793b98f315dc90a57d81006
Nov 10 01:57:24 etechpt.com dockerd[1474]: time="2019-11-10T01:57:24.091797103-05:00" level=info msg="ignoring event" module=libcontainerd
Nov 23 15:36:56 etechpt.com systemd[1]: Stopping Docker Application Container Engine...
Nov 23 15:36:56 etechpt.com dockerd[1474]: time="2019-11-23T15:36:56.992795411-05:00" level=info msg="Processing signal 'terminated'"
Nov 23 15:36:58 etechpt.com dockerd[1474]: time="2019-11-23T15:36:58.234014533-05:00" level=info msg="ignoring event" module=libcontainerd
Nov 23 15:37:00 etechpt.com dockerd[1474]: time="2019-11-23T15:37:00.403572098-05:00" level=info msg="ignoring event" module=libcontainerd
Nov 23 15:37:00 etechpt.com systemd[1]: Stopped Docker Application Container Engine.
Modificando docker.conf e docker.socket
Nesta etapa, o objetivo é alterar o caminho do arquivo docker.sock de /var/run/docker.sock para, por exemplo, /home/etechpt.com/docker.sock. Os seguintes passos são cruciais:
- Edite o arquivo
docker.conf: Este arquivo está localizado em/etc/init/. Nele, localize e modifique a linha que define o caminhoDOCKER_SOCKET.
[email protected]:~$ sudo gedit /etc/init/docker.conf
description "Docker daemon"
start on (filesystem and net-device-up IFACE!=lo)
stop on runlevel [!2345]
limit nofile 524288 1048576
# Having non-zero limits causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
limit nproc unlimited unlimited
respawn
kill timeout 20
pre-start script
# see also https://github.com/tianon/cgroupfs-mount/blob/master/cgroupfs-mount
if grep -v '^#' /etc/fstab | grep -q cgroup
|| [ ! -e /proc/cgroups ]
|| [ ! -d /sys/fs/cgroup ]; then
exit 0
fi
if ! mountpoint -q /sys/fs/cgroup; then
mount -t tmpfs -o uid=0,gid=0,mode=0755 cgroup /sys/fs/cgroup
fi
(
cd /sys/fs/cgroup
for sys in $(awk '!/^#/ { if ($4 == 1) print $1 }' /proc/cgroups); do
mkdir -p $sys
if ! mountpoint -q $sys; then
if ! mount -n -t cgroup -o $sys cgroup $sys; then
rmdir $sys || true
fi
fi
done
)
end script
script
# modify these in /etc/default/$UPSTART_JOB (/etc/default/docker)
DOCKERD=/usr/bin/dockerd
DOCKER_OPTS=
if [ -f /etc/default/$UPSTART_JOB ]; then
. /etc/default/$UPSTART_JOB
fi
exec "$DOCKERD" $DOCKER_OPTS --raw-logs
end script
# Don't emit "started" event until docker.sock is ready.
# See https://github.com/docker/docker/issues/6647
post-start script
DOCKER_OPTS=
DOCKER_SOCKET=
if [ -f /etc/default/$UPSTART_JOB ]; then
. /etc/default/$UPSTART_JOB
fi
if ! printf "%s" "$DOCKER_OPTS" | grep -qE -e '-H|--host'; then
DOCKER_SOCKET=/home/etechpt.com/docker.sock
else
DOCKER_SOCKET=$(printf "%s" "$DOCKER_OPTS" | grep -oP -e '(-H|--host)W*unix://K(S+)' | sed 1q)
fi
if [ -n "$DOCKER_SOCKET" ]; then
while ! [ -e "$DOCKER_SOCKET" ]; do
initctl status $UPSTART_JOB | grep -qE "(stop|respawn)/" && exit 1
echo "Waiting for $DOCKER_SOCKET"
sleep 0.1
done
echo "$DOCKER_SOCKET is up"
fi
end script
- Edite o arquivo
docker.socket: Este arquivo, localizado em/lib/systemd/system/, também precisa ser alterado para refletir o novo caminho dodocker.sock.
[email protected]:~$ sudo gedit /lib/systemd/system/docker.socket
[Unit]
Description=Docker Socket for the API
PartOf=docker.service
[Socket]
ListenStream=/home/etechpt.com/docker.sock
SocketMode=0660
SocketUser=root
SocketGroup=docker
[Install]
WantedBy=sockets.target
Após as modificações, é necessário recarregar o daemon do systemd para que as alterações tenham efeito.
[email protected]:~$ sudo systemctl daemon-reload
Reiniciando o Docker
Agora, vamos iniciar o serviço Docker novamente e verificar seu status. Ao final do log de status, você deverá ver o novo caminho do arquivo docker.sock.
[email protected]:~$ sudo service docker start
[email protected]:~$ sudo service docker status
docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: active (running) since Sat 2019-11-23 15:39:36 EST; 3s ago
Docs: https://docs.docker.com
Main PID: 8840 (dockerd)
Tasks: 17
Memory: 47.6M
CGroup: /system.slice/docker.service
└─8840 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
Nov 23 15:39:35 etechpt.com dockerd[8840]: time="2019-11-23T15:39:35.091941184-05:00" level=warning msg="Your kernel does not support cgroup rt runtime"
Nov 23 15:39:35 etechpt.com dockerd[8840]: time="2019-11-23T15:39:35.093149218-05:00" level=info msg="Loading containers: start."
Nov 23 15:39:35 etechpt.com dockerd[8840]: time="2019-11-23T15:39:35.957842188-05:00" level=info msg="Default bridge (docker0) is assigned with an IP address 172.17.0.0/16. Daemon
Nov 23 15:39:36 etechpt.com dockerd[8840]: time="2019-11-23T15:39:36.078753190-05:00" level=info msg="Loading containers: done."
Nov 23 15:39:36 etechpt.com dockerd[8840]: time="2019-11-23T15:39:36.664727326-05:00" level=info msg="Docker daemon" commit=481bc77 graphdriver(s)=overlay2 version=18.09.6
Nov 23 15:39:36 etechpt.com dockerd[8840]: time="2019-11-23T15:39:36.817929464-05:00" level=error msg="cluster exited with error: error while loading TLS certificate in /var/lib/do
Nov 23 15:39:36 etechpt.com dockerd[8840]: time="2019-11-23T15:39:36.820439024-05:00" level=error msg="swarm component could not be started" error="error while loading TLS certific
Nov 23 15:39:36 etechpt.com dockerd[8840]: time="2019-11-23T15:39:36.820821712-05:00" level=info msg="Daemon has completed initialization"
Nov 23 15:39:36 etechpt.com systemd[1]: Started Docker Application Container Engine.
Nov 23 15:39:36 etechpt.com dockerd[8840]: time="2019-11-23T15:39:36.883382952-05:00" level=info msg="API listen on /home/etechpt.com/docker.sock"
Para confirmar que o arquivo docker.sock foi criado no novo caminho, utilize o comando ls.
[email protected]:~$ ls -l
total 466832
-rw-r--r-- 1 etechpt.com etechpt.com 0 Oct 23 05:32 ]
drwxr-xr-x 9 tomcat tomcat 4096 Nov 18 14:30 apache-tomcat-9.0.27
-rw-r--r-- 1 etechpt.com etechpt.com 10982406 Oct 7 06:21 apache-tomcat-9.0.27.tar.gz
drwxr-xr-x 8 etechpt.com etechpt.com 4096 Oct 23 06:05 chef-repo
-rw-r--r-- 1 etechpt.com etechpt.com 252269838 Jul 1 15:16 chef-server-core_13.0.17-1_amd64.deb
-rw-r--r-- 1 etechpt.com etechpt.com 129713682 Dec 27 2018 chef-workstation_0.2.43-1_amd64.deb
drwxr-xr-x 2 etechpt.com etechpt.com 4096 Oct 23 2018 Desktop
-rw-r--r-- 1 etechpt.com etechpt.com 726 Jul 27 15:10 Dockerfile
srw-rw---- 1 root docker 0 Nov 23 15:39 docker.sock
drwxr-xr-x 2 etechpt.com etechpt.com 4096 Oct 23 2018 Documents
drwxr-xr-x 2 etechpt.com etechpt.com 4096 Jul 20 18:20 Downloads
-rw-r--r-- 1 etechpt.com etechpt.com 8980 Oct 23 2018 examples.desktop
Com essas etapas concluídas, você alterou com sucesso a localização do arquivo docker.sock.
Se você deseja aprofundar seus conhecimentos em Docker, considere explorar este curso intensivo.
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