art: Drop provider from c3os code

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

pkg/machine/systemd/unit.go

@@ -0,0 +1,115 @@
+package systemd
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/c3os-io/c3os/pkg/utils"
+)
+
+type ServiceUnit struct {
+	content        string
+	name, instance string
+	rootdir        string
+}
+
+const overrideCmdTemplate string = `
+[Service]
+ExecStart=
+ExecStart=%s
+`
+
+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 WithInstance(n string) ServiceOpts {
+	return func(su *ServiceUnit) error {
+		su.instance = 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 s.instance != "" {
+		uname = fmt.Sprintf("%s@", s.name)
+	}
+
+	if err := ioutil.WriteFile(filepath.Join(s.rootdir, fmt.Sprintf("/etc/systemd/system/%s.service", uname)), []byte(s.content), 0600); err != nil {
+		return err
+	}
+
+	_, err := utils.SH("systemctl daemon-reload")
+	return err
+}
+
+func (s ServiceUnit) OverrideCmd(cmd string) error {
+	svcDir := filepath.Join(s.rootdir, fmt.Sprintf("/etc/systemd/system/%s.service.d/", s.name))
+	os.MkdirAll(svcDir, 0600) //nolint:errcheck
+
+	return ioutil.WriteFile(filepath.Join(svcDir, "override.conf"), []byte(fmt.Sprintf(overrideCmdTemplate, cmd)), 0600)
+}
+
+func (s ServiceUnit) Start() error {
+	return s.systemctl("start", false)
+}
+
+func (s ServiceUnit) Restart() error {
+	return s.systemctl("restart", false)
+}
+
+func (s ServiceUnit) Enable() error {
+	return s.systemctl("enable", false)
+}
+
+func (s ServiceUnit) StartBlocking() error {
+	return s.systemctl("start", true)
+}
+
+func (s ServiceUnit) systemctl(action string, blocking bool) error {
+	uname := s.name
+	if s.instance != "" {
+		uname = fmt.Sprintf("%s@%s", s.name, s.instance)
+	}
+	args := []string{action}
+	if !blocking {
+		args = append(args, "--no-block")
+	}
+	args = append(args, uname)
+
+	_, err := utils.SH(fmt.Sprintf("systemctl %s", strings.Join(args, " ")))
+	return err
+}