Docker version 1.11 is a big change,
First, the first mock exam is divided into 4 independent modules from single module, engine, containerd, runc and containerd-shim.
Containerd shim replaces the original process 1 and is used to recycle orphan processes
Containerd is used to manage the life cycle of containers,
Runc is used to run the container
This change made it more compliant and standardized in 2017
In order to install the version before 1.11, I tried for almost 4 hours
The main reason is that almost all apt installation packages have been offline
Students who want to try can follow the following steps
Download the DEB offline package and install it with Ubuntu 16. 18 and 20 are not compatible
http://archive.ubuntu.com/ubuntu/pool/universe/d/docker.io/docker.io_1.10.3-0ubuntu6_amd64.deb
Start a Ubuntu image, block its No. 1 process, and generate a zombie process by reference
Kill process 42, so that the parent process of process 45 will become process 1 of the container
Then kill process 45. At this time, process 1 of the container should not be able to recycle it
Then we get a zombie process that can’t be recycled
