Split off cli into separate binaries (#37)

* 🎨 Split off cli into separate binaries

This commit splits off the cli into 3 binaries:
- agent
- cli
- provider

The provider now is a separate component that can be tested by itself
and have its own lifecycle. This paves the way to a ligher c3os variant,
HA support and other features that can be provided on runtime.

This is working, but still there are low hanging fruit to care about.

Fixes #14

* 🤖 Add provider bin to releases

* ⚙️ Handle signals

* ⚙️ Reduce buildsize footprint

* 🎨 Scan for providers also in /system/providers

* 🤖 Run goreleaser

* 🎨 Refactoring

internal/utils/system.go

@@ -0,0 +1,82 @@
+package utils
+
+import (
+	"fmt"
+	"net"
+	"strings"
+
+	"github.com/joho/godotenv"
+	"github.com/pterm/pterm"
+)
+
+func Reboot() {
+	pterm.Info.Println("Rebooting node")
+	SH("reboot")
+}
+
+func PowerOFF() {
+	pterm.Info.Println("Shutdown node")
+	if IsOpenRCBased() {
+		SH("poweroff")
+	} else {
+		SH("shutdown")
+	}
+}
+
+func Version() string {
+	release, _ := godotenv.Read("/etc/os-release")
+	v := release["VERSION"]
+	v = strings.ReplaceAll(v, "+k3s1-c3OS", "-")
+	return strings.ReplaceAll(v, "+k3s-c3OS", "-")
+}
+
+func OSRelease(key string) (string, error) {
+	release, err := godotenv.Read("/etc/os-release")
+	if err != nil {
+		return "", err
+	}
+	v, exists := release[key]
+	if !exists {
+		return "", fmt.Errorf("key not found")
+	}
+	return v, nil
+}
+
+func Flavor() string {
+	release, _ := godotenv.Read("/etc/os-release")
+	v := release["NAME"]
+	return strings.ReplaceAll(v, "c3os-", "")
+}
+
+func IsOpenRCBased() bool {
+	f := Flavor()
+	return f == "alpine" || f == "alpine-arm-rpi"
+}
+
+func GetInterfaceIP(in string) string {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		fmt.Println("failed getting system interfaces")
+		return ""
+	}
+	for _, i := range ifaces {
+		if i.Name == in {
+			addrs, _ := i.Addrs()
+			// handle err
+			for _, addr := range addrs {
+				var ip net.IP
+				switch v := addr.(type) {
+				case *net.IPNet:
+					ip = v.IP
+				case *net.IPAddr:
+					ip = v.IP
+				}
+				if ip != nil {
+					return ip.String()
+
+				}
+			}
+		}
+	}
+	return ""
+}