capi system: clean up etcd dir

Etcd data is preserved to support the standalone
openshift-install destroy bootstrap command. We can only delete this
once bootstrap destroy has been completed. Teardown may be called
in other cases, such as an error or user interrupt, so this commit
introduces a separate function to delete the etcd directoy specifically.

pkg/clusterapi/system.go

@@ -59,6 +59,7 @@ type Interface interface {
 	State() SystemState
 	Client() client.Client
 	Teardown()
+	CleanEtcd()
 }
 
 // System returns the cluster-api system.
@@ -393,6 +394,21 @@ func (c *system) Teardown() {
 	})
 }
 
+// CleanEtcd removes the etcd database from the host.
+func (c *system) CleanEtcd() {
+	c.Lock()
+	defer c.Unlock()
+
+	if c.lcp == nil {
+		return
+	}
+
+	// Clean up the etcd directory.
+	if err := os.RemoveAll(c.lcp.EtcdDataDir); err != nil {
+		logrus.Warnf("Unable to delete local etcd data directory %s. It is safe to remove the directory manually", c.lcp.EtcdDataDir)
+	}
+}
+
 // State returns the state of the cluster-api system.
 func (c *system) State() SystemState {
 	c.Lock()