MyDocker

DIY Docker，Just For Fun.

Thanks for the following two books:

How To Play

Build

• This project is developed on MacOS, with golang version go1.17.1 darwin/amd64.
• This project contains cgo code.

Build on MacOS

Take MacOS for example:

• First, install x86_64-linux-musl-gcc

arch -x86_64 brew install FiloSottile/musl-cross/musl-cross

• build with the following command:

CC=x86_64-linux-musl-gcc CGO_ENABLED=1 GOOS=linux GOARCH=amd64  go build -ldflags "-linkmode external -extldflags -static" -o my-docker main.go

Remote Debug

In order to debug my-docker in linux os env:

1. Install go on ubuntu linux
2. Install delve

go install github.com/go-delve/delve/cmd/dlv@latest

3. Compile with dlv:

CC=x86_64-linux-musl-gcc CGO_ENABLED=1 GOOS=linux GOARCH=amd64  go build -ldflags "-linkmode external -extldflags -static" -gcflags "all=-N -l" -o my-docker-dlv main.go

4. Start dlv on ubuntu

dlv --listen=:2345 --headless=true --api-version=2 --accept-multiclient exec ./my-docker-dlv [command] -- [-option of my-docker]

5. Use Go Remote in IDEA to start remote debug

Play

Environment

Linux ubuntu-linux 4.4.0-142-generic #168~14.04.1-Ubuntu SMP Sat Jan 19 11:26:28 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Setup

• make sure cgroup is mounted
• play with root user
• for network:

echo 1 > /proc/sys/net/ipv4/ip_forward

• uzip my-docker.tar in /root
• play with my-docker after chmod

Commands

USAGE:
   my-docker [global options] command [command options] [arguments...]

COMMANDS:
   exec     exec a command into container
   init     Init container process run user's process in container. Do not call it outside
   ps       list all containers
   logs     print logs of a container
   rm       remove unused container
   run      create a container: my-docker run -ti [command]
   stop     stop a container
   network  container network commands
   commit   commit a container to image
   image    image commands
   help, h  Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --help, -h  show help

run command

USAGE:
   my-docker run [command options] [arguments...]

OPTIONS:
   --ti              enable tty
   -d                detach container
   --mem value       memory limit
   --cpushare value  cpushare limit
   --cpuset value    cpuset limit
   --name value      container name
   -e value          set environment
   --net value       container network
   -p value          port mapping

image command

USAGE:
   my-docker image command [command options] [arguments...]

COMMANDS:
   ls  list images

OPTIONS:
   --help, -h  show help

network command

USAGE:
   my-docker network command [command options] [arguments...]

COMMANDS:
   create  create a container network
   ls      list container network
   rm      remove container network

OPTIONS:
   --help, -h  show help

Images

• not support push/pull command with repositories
• only support make new image with commit command
• two built-in images:

REPOSITORY   TAG         IMAGE ID
busybox      1.0.0       7bad98125db6
busybox      test        01ca9b37f1c4

The busybox:1.0.0 provides a simplified linux environment。