added system config and actions

system.go

@@ -0,0 +1,84 @@
+package alpine_builder
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/GehirnInc/crypt"
+	_ "github.com/GehirnInc/crypt/sha256_crypt"
+)
+
+// system configurations
+var systemShadow = "/data/etc/shadow"
+var systemDropbearConfig = "/data/etc/dropbear/dropbear.conf"
+var systemDropbearRestart = "rc-service dropbear start"
+var systemShutdown = "poweroff"
+var systemReboot = "reboot"
+
+// SystemSetRootPassword update shadow file
+func SystemSetRootPassword(password string) error {
+	crypter := crypt.SHA256.New()
+
+	// generate password line
+	hash, err := crypter.Generate([]byte(password), nil)
+	if err != nil {
+		return fmt.Errorf("failed to generate hash: %w", err)
+	}
+	line := fmt.Sprintf("root:%s:0:0:::::", hash)
+
+	// write shadow file
+	return ioutil.WriteFile(systemShadow, []byte(line), os.ModePerm)
+}
+
+// SystemEnableSSH server
+func SystemEnableSSH() error {
+	err := ioutil.WriteFile(systemDropbearConfig, []byte("DROPBEAR_OPTS=\"\""), os.ModePerm)
+	if err != nil {
+		return fmt.Errorf("failed to write ssh config: %w", err)
+	}
+
+	cmdSplit := strings.Split(systemDropbearRestart, " ")
+	cmd := exec.Command(cmdSplit[0], cmdSplit[1:]...)
+	err = cmd.Run()
+	if err != nil {
+		return fmt.Errorf("failed to restart ssh server: %w", err)
+	}
+	return nil
+}
+
+// SystemDisableSSH server
+func SystemDisableSSH() error {
+	err := ioutil.WriteFile(systemDropbearConfig, []byte("DROPBEAR_OPTS=\"-p 127.0.0.1:22\""), os.ModePerm)
+	if err != nil {
+		return fmt.Errorf("failed to write ssh config: %w", err)
+	}
+
+	cmdSplit := strings.Split(systemDropbearRestart, " ")
+	cmd := exec.Command(cmdSplit[0], cmdSplit[1:]...)
+	err = cmd.Run()
+	if err != nil {
+		return fmt.Errorf("failed to restart ssh server: %w", err)
+	}
+	return nil
+}
+
+func SystemShutdown() error {
+	cmd := exec.Command(systemShutdown)
+	err := cmd.Run()
+	if err != nil {
+		return fmt.Errorf("failed to start system shutdown: %w", err)
+	}
+	return nil
+}
+
+func SystemReboot() error {
+	cmd := exec.Command(systemReboot)
+	err := cmd.Run()
+	if err != nil {
+		return fmt.Errorf("failed to start system reboot: %w", err)
+	}
+	return nil
+}