feat: added json file to simulate db

create-container/README.md

@@ -0,0 +1,9 @@
+# Create a container from scratch
+
+
+## Get started
+```bash
+sudo su
+go build .
+./jb-container run /bin/bash
+```

create-container/go.mod

@@ -1,3 +1,3 @@
-module c-container
+module jb-container
 
 go 1.21.0

create-container/main.go

@@ -3,25 +3,84 @@ package main
 import (
 	"fmt"
 	"os"
+	"os/exec"
+	"syscall"
 )
 
-func runContainer() {
-	fmt.Println("Sup")
+func runContainer(args []string) {
+	fmt.Printf("Running %v as PID %d\n", args[2:], os.Getppid())
+	cmd := exec.Command("/proc/self/exe", append([]string{"child"}, args[2:]...)...)
+
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		Cloneflags: syscall.CLONE_NEWUTS | syscall.CLONE_NEWPID,
+	}
+
+	isFuncPanic(cmd.Run())
 }
 
-func main() {
-	var cmds [1]string
+func runContainerChild(args []string) {
+
+	cmd := exec.Command(args[2], args[3:]...)
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
 
-	cmds[0] = "run"
+	isFuncPanic(syscall.Chroot(os.Getenv("HOME")))
+	isFuncPanic(os.Chdir("/"))
+	isFuncPanic(syscall.Mount("proc", "proc", "proc", 0, ""))
+	isFuncPanic(cmd.Run())
 
-	if len(os.Args) < 2 {
-		panic("Provide at leas 1 argument")
+	isFuncPanic(cmd.Run())
+}
+
+func messageHelper(cmds []string, opts []string) {
+	cmdsDescriptions := []string{
+		"you can start a container",
+		"run as a child",
+	}
+	optsDescriptions := []string{
+		"provides message helper",
+	}
+
+	fmt.Println("Usage: jb-docker [COMMAND] [OPTIONS]")
+	fmt.Println("\nAvailable commands:")
+	for idxCmd := range cmds {
+		fmt.Println(fmt.Sprintf("[%s] - %s", cmds[idxCmd], cmdsDescriptions[idxCmd]))
+	}
+	fmt.Println("\nAvailable options:")
+	for idxOpt := range opts {
+		fmt.Println(fmt.Sprintf("[%s] - %s", opts[idxOpt], optsDescriptions[idxOpt]))
 	}
-	fmt.Println(len(os.Args))
-	switch os.Args[1] {
+}
+
+func startContainer(args []string) {
+	cmds := []string{"run", "child"}
+	opts := []string{"--help"}
+
+	if len(args) < 2 {
+		panic("Provide at least 1 argument")
+	}
+	switch args[1] {
 	case cmds[0]:
-		runContainer()
+		runContainer(args)
+	case cmds[1]:
+		runContainerChild(args)
+	case opts[0]:
+		messageHelper(cmds, opts)
 	default:
-		panic("Provide at leas 1 argument")
+		fmt.Println(fmt.Sprintf("jb-docker: '%s' is not a jb-docker command.\nSee 'jb-docker --help'", args[1]))
+	}
+}
+
+func isFuncPanic(err error) {
+	if err != nil {
+		panic(err)
 	}
 }
+
+func main() {
+	startContainer(os.Args)
+}