sparkles: state api sdk (#262)

* ✨ Add state api

This is related to https://github.com/kairos-io/kairos/issues/34.

Starts to unify the API to retrieve the state in the sdk to have a common place to query system status information.

* 🤖 Add test

* Update go.mod

* ⚙️ Fine-tune detection of partitions

* 🤖 Add more fine-grained tests

* 🎨 Add /dev/ to partition name

* 🤖 Fixup tests

* ⚙️ Remount accessors

* ✨ Add state partition to cloud-init paths

* 📝 Upper case Kairos in motd

* 🎨 Add mounts sdk

* 🎨 Set grub options via SDK

* 🎨 Make it more idiomatic

sdk/system/grub.go

@@ -0,0 +1,47 @@
+package system
+
+import (
+	"fmt"
+
+	"github.com/kairos-io/kairos/pkg/machine"
+	"github.com/kairos-io/kairos/pkg/utils"
+	"github.com/kairos-io/kairos/sdk/mounts"
+	"github.com/kairos-io/kairos/sdk/state"
+)
+
+func SetGRUBOptions(opts map[string]string) Option {
+	return func(c *Changeset) error {
+		if len(opts) > 0 {
+			c.Add(func() error { return setGRUBOptions(opts) })
+		}
+		return nil
+	}
+}
+
+func setGRUBOptions(opts map[string]string) error {
+	runtime, err := state.NewRuntime()
+	if err != nil {
+		return err
+	}
+
+	oem := runtime.OEM
+	if runtime.OEM.Name == "" {
+		oem = runtime.Persistent
+	}
+
+	if err := mounts.PrepareWrite(oem, "/tmp/oem"); err != nil {
+		return err
+	}
+	defer func() {
+		machine.Umount("/tmp/oem") //nolint:errcheck
+	}()
+
+	for k, v := range opts {
+		out, err := utils.SH(fmt.Sprintf(`grub2-editenv /tmp/oem/grubenv set "%s=%s"`, k, v))
+		if err != nil {
+			fmt.Printf("could not set boot option: %s\n", out+err.Error())
+		}
+	}
+
+	return nil
+}