Root filesystem building guide

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What do you need for building a rootfs file?

A server which operation system is Ubuntu 14.04 or Debian 8.

How to build a rootfs file in a server?

• Get a LXC_Rootfs directory with a shell script by git command.
  git clone https://github.com/HuaweiSwitch/LXC_Rootfs.git
• Add permission for the LXC_Rootfs directory.
  chmod 777 -R LXC_Rootfs/
• Configure repo and source of apt-get before building process.
  apt-get update
• Install docker by install the docker-io package in server.
  apt-get install -y docker.io qemu qemu-user-static
• Add the docker package links.
  ln -sf /usr/bin/docker.io /usr/local/bin/docker
• Pull the specific image from a docker registry server, for example:1587/osc-builder.
  docker pull 1587/osc-builder
• Launch a container which build by the image.
  sudo docker run -v ~/LXC_Rootfs:/data -v /dev:/dev -v /lib/modules/:/lib/modules/ --add-host='osc:127.0.0.1' --privileged -i -t 1587/osc-builder:latest /bin/bash
• Enter into the /data/ directory and execute the shell script with the parameter to make file system folder.
  cd /data
./create_rootfs.sh {powerpc|armel}　(PS: The passwd for osc-builder is osc-buidler.)
  Attention:If the architecture of device is arm, please choose the “armel” as parameter, otherwise choose the “powerpc”.
• Install qemu and qemu-user-static package.     apt-get install qemu qemu-user-static
• Install squashfs-tools package in server.
  apt-get install squashfs-tools
• Create root file system into a rootfs file with sqfs format.
  mksquashfs {powerpc|armel}-rootfs/ rootfs.sqfs (PS: If the "armel" has been selected as a parameter, the command should be executed:chmod 100000:100000 -R rootfs/ before executing the mksquashfs command.)

How to start a lxc container with rootfs file in CE switch?

• Transfer the rootfs file to CE switch.
  using ftp tools to transfer rootfs.sqfs from local computer to CE switch.　　
• Load the lxc firmware with command.
  bash shell rootfs.sqfs　　
• Enter the container with command.
  bash
• Exit from the container.
  Ctrl + a q　　
• Unable the container with command.
  undo bash shell rootfs.sqfs

Q&A

• When you set or change your password for user in linux container with the armel rootfs, you may meet error information as below: passwd: System error passwd: password unchanged

To solve this problem, you should compile the passwd ball in armel cross compile tool again with "--without-libpam" and "--without-audit", which will be installed in linux container.

References

[1] For docker instruction: https://opensource.com/recources/what-docker

[2] For docker details: https://www.docker.com