docker

一个“容器”，实际上是一个由Linux Namespace、Linux Cgroups和rootfs三种技术构建出来的进程的隔离环境。

一个正在运行的 Linux 容器，其实可以被“一分为二”地看待：

• 一组联合挂载在 /var/lib/docker/aufs/mnt 上的 rootfs，这一部分我们称为“容器镜像”（Container Image），是容器的静态视图；
• 一个由 Namespace+Cgroups 构成的隔离环境，这一部分我们称为“容器运行时”（Container Runtime），是容器的动态视图。

端口映射

docker容器端口映射是：前容器port:后宿主机port，如8080:38080

docker容器内换源

docker exec -it -u root id /bin/bash

cp /etc/apt/sources.list /etc/apt/sources.list.bak

cat > /etc/apt/sources.list <<EOF
deb https://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
# deb https://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse
# deb-src https://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse
EOF

apt-get update
apt-get upgrade -y

apt-get install -y vim