Instalando Docker

Remover versões antigas:

sudo apt-get remove docker docker-engine docker.io containerd runc

Atualizar o sistema:

sudo apt update

sudo apt-get install \
    ca-certificates \
    curl \
    gnupg \
    lsb-release

Adicionar chave oficial Docker:

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

Adicionar o repositório

 echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Instalar o Docker Engine

sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io

Criar o grupo de usuário do docker

sudo groupadd docker

Adicionar o usuário ao grupo

sudo usermod -aG docker $USER

Sair do terminal e entrar novamente

newgrp docker

Verificar se docker pode rodar sem sudo:

docker ps

Erro:

Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get "http://%2Fvar%2Frun%2Fdocker.sock/v1.24/containers/json": dial unix /var/run/docker.sock: connect: permission denied

sudo chmod 666 /var/run/docker.sock

Mais informações:

https://docs.docker.com/engine/install/linux-postinstall/

Mais informações:

https://docs.docker.com/engine/install/ubuntu/