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/role/worker.go

@@ -0,0 +1,108 @@
+package role
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/c3os-io/c3os/internal/machine"
+	"github.com/c3os-io/c3os/internal/utils"
+	"github.com/c3os-io/c3os/pkg/config"
+
+	service "github.com/mudler/edgevpn/api/client/service"
+)
+
+func Worker(cc *config.Config) Role {
+	return func(c *service.RoleConfig) error {
+
+		if cc.C3OS.Role != "" {
+			// propagate role if we were forced by configuration
+			// This unblocks eventual auto instances to try to assign roles
+			c.Client.Set("role", c.UUID, cc.C3OS.Role)
+		}
+
+		if SentinelExist() {
+			c.Logger.Info("Node already configured, backing off")
+			return nil
+		}
+
+		masterIP, _ := c.Client.Get("master", "ip")
+		if masterIP == "" {
+			c.Logger.Info("MasterIP not there still..")
+			return nil
+		}
+
+		nodeToken, _ := c.Client.Get("nodetoken", "token")
+		if masterIP == "" {
+			c.Logger.Info("nodetoken not there still..")
+			return nil
+		}
+
+		nodeToken = strings.TrimRight(nodeToken, "\n")
+
+		ip := utils.GetInterfaceIP("edgevpn0")
+		if ip == "" {
+			return errors.New("node doesn't have an ip yet")
+		}
+
+		c.Logger.Info("Configuring k3s-agent", ip, masterIP, nodeToken)
+
+		svc, err := machine.K3sAgent()
+		if err != nil {
+			return err
+		}
+
+		k3sConfig := config.K3s{}
+		if cc.K3sAgent.Enabled {
+			k3sConfig = cc.K3sAgent
+		}
+
+		env := map[string]string{
+			"K3S_URL":   fmt.Sprintf("https://%s:6443", masterIP),
+			"K3S_TOKEN": nodeToken,
+		}
+
+		if !k3sConfig.ReplaceEnv {
+			// Override opts with user-supplied
+			for k, v := range k3sConfig.Env {
+				env[k] = v
+			}
+		} else {
+			env = k3sConfig.Env
+		}
+
+		// Setup systemd unit and starts it
+		if err := utils.WriteEnv(machine.K3sEnvUnit("k3s-agent"),
+			env,
+		); err != nil {
+			return err
+		}
+
+		args := []string{
+			"--with-node-id",
+			fmt.Sprintf("--node-ip %s", ip),
+			"--flannel-iface=edgevpn0",
+		}
+		if k3sConfig.ReplaceArgs {
+			args = k3sConfig.Args
+		} else {
+			args = append(args, k3sConfig.Args...)
+		}
+
+		if err := svc.OverrideCmd(fmt.Sprintf("/usr/bin/k3s agent %s", strings.Join(args, " "))); err != nil {
+			return err
+		}
+
+		if err := svc.Start(); err != nil {
+			return err
+		}
+
+		if err := svc.Enable(); err != nil {
+			return err
+		}
+
+		CreateSentinel()
+
+		return nil
+	}
+}