Containerization Oriented Standard Operations
In Italian, the word "coso" is an informal term that is used to refer to a thing, object, or an unspecified item. It is often used when the specific name or term for something is not known or forgotten. It can also be used as a placeholder word when referring to a person whose name you can't remember or don't want to mention. In English, "coso" can be loosely translated as "thingy," "whatchamacallit," or "doodad."
- 30/06/23 - project start
Supported Namespaces:
- PID
- Network
- UTS - aka hostname
- User
- Mount
- IPC
- Cgroups (work in progress)
COSO is mainly a study project to apply teachings on Linux containers internals. In the long run, the project should evolve in a Docker-like CLI capable of reading configurations files and spin up containers according to the given instructions.
Right now (01/07/23) some areas of COSO are not handled directly by the main binary executable.
- Filesystem: a minimal Alpine distribution for x86_64 architecture is provided and used as lower layer
- Networking: the configuration of the necessary devices used to route traffic from the standard namespace to the newly created one(s) is handled by a separate bynary: cosonet
You can run make fs-setup and make net-setup to configure the above.
Or just make run and follow the error messages :)
IF the setup has been successfull, you should be able to run COSO with make run.
Note that if you have previosly installed Docker and are using the default network manager (cosonet), Internet access in the created network namespace may not be available as a result of Docker changing the iptables FORWARD chain policy to DROP.
To verify this is the case, use the command
sudo iptables -L
To enable packets forwarding to the custom interfaces handled by COSO, you can run the command
sudo iptables -P FORWARd ACCEPT
COSO expects a path to a root filesystem, to use as lower layer, and to an executable which can handle network devices creation. COSO will execute the following call when trying to setup network devices for the new process (running in a separate namespace):
<path to the executable> -pid <pid of the child process>
You can modify the 2 above mentioned paths with the following flags
| Flag | Type | Default | Meaning |
|---|---|---|---|
| rootfs | string | /tmp/coso/rootfs | path to the root filesystem |
| network | string | /usr/local/bin/cosonet | path to the executable which will handle the setup of network devices |