A Simple Introduction to Docker IX
What are some concerns about using docker?
Shared kernel concern
Since containers share the same kernel, if one of them panics, everyone of them will panic too.
if a user or application has superuser privileges within the container, the underlying operating system could, in theory, be cracked.1
This concern will no longer be valid in a few months
Docker has been working on linux
user namespacefor a while now. And once this feature is completed. Then we can build a docker container without root privileges, and meanwhile in this container, we can still have enough privileges for us to do our job.
VM + Container
Hyper is a chinese startup project to make a lightweight virtual machine based on Docker images, which combines both advantages from container and VM.
- Its containers are isolated by VM. So it is immune from the "shared kernel" problem in containers.
- It's almost as lightweight as a container. So it's way more fast than a VM.
- Since it's a VM, you can choose your own kernel.
- DevOps needs to manage too many docker files.
- Since in docker's world, we need to seperate each of our apps into a single docker image.
- We must keep our eyes on many different docker files.
- This can be a problem when our project becomes so much big.
- But in general you won't face this.