使用容器方式快速开始UOS应用开发

按正常安装kvm虚拟机的步骤，安装一台UOS虚拟机，虚机的磁盘布局如下所示，可见其根分区的尺寸并不大：    

正常关机后，在host机器上执行如下操作，:

apt install -y docker.io guestfish
qemu-img convert -f qcow2 -O raw  uos10G.qcow2 uos10G.img
guestfish -a uos10G.img --ro

Welcome to guestfish, the guest filesystem shell for
editing virtual machine filesystems and disk images.

Type: ‘help’ for help on commands
      ‘man’ to read the manual
      ‘quit’ to quit the shell

><fs> run
><fs> list-filesystems
/dev/sda1: ext4
/dev/sda2: ext4
><fs> mount /dev/sda2 /
><fs> mount /dev/sda1 /boot
><fs> tar-out / - | xz --best >> myuos.xz
><fs> exit
 cat myuos.xz | docker import - uoskkk
root@delli9:~# docker images
REPOSITORY   TAG       IMAGE ID       CREATED          SIZE
uoskkk     latest    2fb3905a142f   18 seconds ago   1.68GB

此时可通过以下命令验证该容器镜像的可用性:

root@delli9:~# docker run -it uosctyun:latest /bin/bash
[root@8d94931f1eb0 /]# cat /etc/issue
\S
Kernel \r on an \m
[root@8d94931f1eb0 /]# cat /etc/uos-release 
UOS Server Enterprise-C 20
[root@8d94931f1eb0 /]# yum makecache

在离线环境下，可以通过绿色版安装docker后，以纯离线式的方式使用该镜像:

[root@uos ~]# tar xzvf docker-24.0.2.tgz 
docker/
docker/docker-proxy
docker/containerd-shim-runc-v2
docker/ctr
docker/docker
docker/docker-init
docker/runc
docker/dockerd
docker/containerd
[root@uos ~]# mv docker/* /usr/bin
[root@uos ~]# dockerd&

在另一个终端上导入镜像，并启动uos容器实例，进入实例后，可执行UOS相关指令进行后续开发:

[root@uos ~]# cat myuos.xz | docker import - uosxj
sha256:e09cca9384977ce87a05d50a50134a8fa44607b19f4586222b835916dddb24a0
[root@uos ~]# docker images
REPOSITORY   TAG       IMAGE ID       CREATED          SIZE
uosxj        latest    e09cca938497   40 seconds ago   1.68GB
[root@uos ~]# docker run --privileged -it uosxj /bin/bash
[root@0bb3783f7e1e /]# yum makecache
[root@0bb3783f7e1e /]# yum install -y qemu-kvm-ev
[root@0bb3783f7e1e /]# /usr/libexec/qemu-kvm  --version
QEMU emulator version 2.12.0 (qemu-kvm-ev-2.12.0-45.uelc20_2.01)
Copyright (c) 2003-2017 Fabrice Bellard and the QEMU Project developers