Docker’s mirror looks more like a class from an object-oriented perspective, while a container is an object created from it
Docker Ecosphere has a large number of mirror warehouses, of course the most well-known are Https://hub.docker.com/
We know that docker images are layered, such as the following Nginx mirrors
As we mentioned in the Difference between Docker and Virtual Machine, containers override the rootfs layer of the Linux host
Build virtual Ubuntu, CentOS, Busybox, CoreOS and other environments on top of the host machine
The principle used is copy-on-write.
Container layers are called writable layers and below them are called mirror layers
All changes to the container, whether added, read-written, or deleted, will only occur in the container layer. Only the container layer is writable and the mirror layer beneath the container layer is read-only.
- Write and delete operations directly at the container layer
- During a read operation, the docker looks for the file from top to next and reads it directly as soon as it is found
