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/provider/challenge_test.go

@@ -0,0 +1,64 @@
+package provider_test
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"os"
+
+	. "github.com/c3os-io/c3os/internal/provider"
+	"github.com/c3os-io/c3os/pkg/bus"
+	"github.com/c3os-io/c3os/pkg/config"
+	"github.com/mudler/go-pluggable"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Challenge provider", func() {
+	Context("network token", func() {
+		e := &pluggable.Event{}
+
+		BeforeEach(func() {
+			e = &pluggable.Event{}
+		})
+
+		It("returns it if provided", func() {
+			f, err := ioutil.TempFile(os.TempDir(), "tests")
+			Expect(err).ToNot(HaveOccurred())
+			defer os.RemoveAll(f.Name())
+
+			cfg := &config.Config{
+				C3OS: &config.C3OS{
+					NetworkToken: "foo",
+				},
+			}
+			c := &bus.EventPayload{Config: cfg.String()}
+			dat, err := json.Marshal(c)
+			Expect(err).ToNot(HaveOccurred())
+
+			e.Data = string(dat)
+			resp := Challenge(e)
+
+			Expect(string(resp.Data)).Should(ContainSubstring("foo"))
+		})
+
+		It("generates it if not provided", func() {
+			f, err := ioutil.TempFile(os.TempDir(), "tests")
+			Expect(err).ToNot(HaveOccurred())
+			defer os.RemoveAll(f.Name())
+
+			cfg := &config.Config{
+				C3OS: &config.C3OS{
+					NetworkToken: "",
+				},
+			}
+			c := &bus.EventPayload{Config: cfg.String()}
+			dat, err := json.Marshal(c)
+			Expect(err).ToNot(HaveOccurred())
+
+			e.Data = string(dat)
+			resp := Challenge(e)
+
+			Expect(len(string(resp.Data))).Should(BeNumerically(">", 12))
+		})
+	})
+})