art: Drop provider from c3os code

Part of: https://github.com/c3os-io/c3os/issues/68

pkg/machine/openrc/unit.go

@@ -0,0 +1,98 @@
+package openrc
+
+import (
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+	"strings"
+
+	"github.com/c3os-io/c3os/pkg/utils"
+)
+
+type ServiceUnit struct {
+	content string
+	name    string
+	rootdir string
+}
+
+type ServiceOpts func(*ServiceUnit) error
+
+func WithRoot(n string) ServiceOpts {
+	return func(su *ServiceUnit) error {
+		su.rootdir = n
+		return nil
+	}
+}
+
+func WithName(n string) ServiceOpts {
+	return func(su *ServiceUnit) error {
+		su.name = n
+		return nil
+	}
+}
+
+func WithUnitContent(n string) ServiceOpts {
+	return func(su *ServiceUnit) error {
+		su.content = n
+		return nil
+	}
+}
+
+func NewService(opts ...ServiceOpts) (ServiceUnit, error) {
+	s := &ServiceUnit{}
+	for _, o := range opts {
+		if err := o(s); err != nil {
+			return *s, err
+		}
+	}
+	return *s, nil
+}
+
+func (s ServiceUnit) WriteUnit() error {
+	uname := s.name
+
+	if err := ioutil.WriteFile(filepath.Join(s.rootdir, fmt.Sprintf("/etc/init.d/%s", uname)), []byte(s.content), 0755); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// TODO: This is too much k3s specific.
+func (s ServiceUnit) OverrideCmd(cmd string) error {
+	k3sbin := utils.K3sBin()
+	if k3sbin == "" {
+		return fmt.Errorf("no k3s binary found (?)")
+	}
+	cmd = strings.ReplaceAll(cmd, k3sbin+" ", "")
+	envFile := filepath.Join(s.rootdir, fmt.Sprintf("/etc/rancher/k3s/%s.env", s.name))
+	env := make(map[string]string)
+	env["command_args"] = fmt.Sprintf("%s >>/var/log/%s.log 2>&1", cmd, s.name)
+
+	return utils.WriteEnv(envFile, env)
+}
+
+func (s ServiceUnit) Start() error {
+	out, err := utils.SH(fmt.Sprintf("/etc/init.d/%s start", s.name))
+	if err != nil {
+		return fmt.Errorf("failed starting service: %s. %s (%w)", s.name, out, err)
+	}
+	return nil
+}
+
+func (s ServiceUnit) Restart() error {
+	out, err := utils.SH(fmt.Sprintf("/etc/init.d/%s restart", s.name))
+	if err != nil {
+		return fmt.Errorf("failed restarting service: %s. %s (%w)", s.name, out, err)
+	}
+	return nil
+}
+
+func (s ServiceUnit) Enable() error {
+	_, err := utils.SH(fmt.Sprintf("ln -sf /etc/init.d/%s /etc/runlevels/default/%s", s.name, s.name))
+	return err
+}
+
+func (s ServiceUnit) StartBlocking() error {
+	return s.Start()
+}