From 3e6917b1cc9dd24e936f9e9a48775284b2a5c152 Mon Sep 17 00:00:00 2001
From: Allen Ray <alray@redhat.com>
Date: Thu, 22 Sep 2022 16:19:09 -0400
Subject: [PATCH] ETCD-319: adding transient systemd unit

---
 etcd/cmd/microshift-etcd/run.go |  1 +
 hack/cleanup.sh                 |  3 +++
 pkg/controllers/etcd.go         | 29 +++++++++++++++++++++++++++--
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/etcd/cmd/microshift-etcd/run.go b/etcd/cmd/microshift-etcd/run.go
index e973ddba9e..a9017d2c61 100644
--- a/etcd/cmd/microshift-etcd/run.go
+++ b/etcd/cmd/microshift-etcd/run.go
@@ -97,6 +97,7 @@ func (s *EtcdService) Run() error {
 	}
 	<-e.Server.ReadyNotify()
 
+	// Wait to be stopped.
 	sigTerm := make(chan os.Signal, 1)
 	signal.Notify(sigTerm, os.Interrupt, syscall.SIGTERM)
 	sig := <-sigTerm
diff --git a/hack/cleanup.sh b/hack/cleanup.sh
index dbaf47749d..68732ff0c7 100755
--- a/hack/cleanup.sh
+++ b/hack/cleanup.sh
@@ -18,6 +18,9 @@ sudo bash -c "
     systemctl disable microshift 2>/dev/null
     pkill -9 microshift
 
+    systemctl stop --now microshift-etcd 2>/dev/null
+    systemctl reset-failed microshift-etcd 2>/dev/null
+
     echo Removing crio container and image storage
     crio wipe -f &>/dev/null || true
     systemctl restart crio
diff --git a/pkg/controllers/etcd.go b/pkg/controllers/etcd.go
index 6f7f4282d7..7479b64c43 100644
--- a/pkg/controllers/etcd.go
+++ b/pkg/controllers/etcd.go
@@ -46,15 +46,39 @@ func (s *EtcdService) Name() string           { return "etcd" }
 func (s *EtcdService) Dependencies() []string { return []string{} }
 
 func (s *EtcdService) Run(ctx context.Context, ready chan<- struct{}, stopped chan<- struct{}) error {
+	defer close(stopped)
+
+	// Check to see if we should run as a systemd run or directly as a binary.
+	runningAsSvc := os.Getenv("INVOCATION_ID") != ""
+
+	// Get the path to the etcd binary based on the MicroShift binary location.
 	microshiftExecPath, err := os.Executable()
 	if err != nil {
 		return fmt.Errorf("%v failed to get exec path: %v", s.Name(), err)
 	}
 	etcdPath := filepath.Join(filepath.Dir(microshiftExecPath), "microshift-etcd")
+	// Not running the etcd binary directly, the proper etcd arguments are handled
+	//		in etcd/cmd/microshift-etcd/run.go.
 	args := []string{"run"}
 
+	// If we're launching MicroShift as a service, we need to do the same
+	//		with etcd, so wrap it in a transient systemd-unit that's tied
+	//		to the MicroShift service lifetime.
+	var exe string
+	if runningAsSvc {
+		args = append([]string{
+			"--uid=root",
+			"--scope",
+			"--property", "BindsTo=microshift.service",
+			"--unit", "microshift-etcd",
+			etcdPath,
+		}, args...)
+		exe = "systemd-run"
+	} else {
+		exe = etcdPath
+	}
 	// Not using context as canceling ctx sends SIGKILL to process
-	cmd := exec.Command(etcdPath, args...)
+	cmd := exec.Command(exe, args...)
 
 	wd, err := os.Getwd()
 	if err != nil {
@@ -63,7 +87,7 @@ func (s *EtcdService) Run(ctx context.Context, ready chan<- struct{}, stopped ch
 	cmd.Dir = wd
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
-	if err := cmd.Start(); err != nil {
+	if err = cmd.Start(); err != nil {
 		return fmt.Errorf("%s failed to start: %v", s.Name(), err)
 	}
 
@@ -87,6 +111,7 @@ func (s *EtcdService) Run(ctx context.Context, ready chan<- struct{}, stopped ch
 	klog.Info("etcd is ready!")
 	close(ready)
 
+	// Wait for MicroShift to be done
 	<-ctx.Done()
 	return ctx.Err()
 }