Dockhomer is a personal project that I start with the goal of understanding how Linux namespaces are used to create containers.
This playground for container creation and configuration allows me to get my hands dirty with the low-level features that Docker uses to make containers simple and effective. It starts with creating processes within the Linux system isolated from the 'host' machine using kernel namespaces:
- UTS: hostname and NIS domain name
- PID: process IDs
- User: user and group IDs
- Mount: mount points
Currently, dockhomer expects a filesystem to be loaded in the home directory -which defaults to /tmp/dockhomer- to
pivot_root to this locations and make it the root filesystem for the container. I'm using busybox for development but the idea
is to add the possibility of selecting the image when calling dockhomer run.
The following are the features I'm focusing on -for now-:
- Running an interactive terminal -
/bin/sh - Passing a given command as argument -
echo "hello, world" - Isolate networking -
virtual interface? - Manage filesystems -images- and allow selecting existing or downloading new ones
- Run a program -
go run main.go - Use custom images -
dockhomer run nginx