cluster: Improve cluster restart messaging (#2442)

Cluster restart messaging indicates to user that the:
  - Cluster will be unavailable
    (https://github.com/pingcap/tiup/blob/654b087a1d293128424c0bd04e1ba216b064ffd1/pkg/cluster/manager/basic.go#L235)

This message is confusing when the command run only requests a single
node restart, especially monitoring nodes or ones in an HA deployment.

Commit changes the messaging so that users performing full cluster
restart retain the same message as before. But users only restarting
selected nodes or roles will have that replaced with a more detailed warning message:

`Cluster functionality related to nodes: %s and roles: % will be
unavailable`

pkg/cluster/manager/basic.go

@@ -231,13 +231,26 @@ func (m *Manager) RestartCluster(name string, gOpt operator.Options, skipConfirm
  }
 
  if !skipConfirm {
- if err := tui.PromptForConfirmOrAbortError(
- fmt.Sprintf("Will restart the cluster %s with nodes: %s roles: %s.\nCluster will be unavailable\nDo you want to continue? [y/N]:",
- color.HiYellowString(name),
- color.HiYellowString(strings.Join(gOpt.Nodes, ",")),
- color.HiYellowString(strings.Join(gOpt.Roles, ",")),
- ),
- ); err != nil {
+ var availabilityMessage string
+ var rolesToRestart string
+ var nodesToRestart string
+ if len(gOpt.Nodes) == 0 && len(gOpt.Roles) == 0 {
+ availabilityMessage = "Cluster will be unavailable"
+ rolesToRestart = "all"
+ nodesToRestart = "all"
+ } else {
+ availabilityMessage = fmt.Sprintf("Cluster functionality related to nodes: %s roles: %s will be unavailable", strings.Join(gOpt.Nodes, ","), strings.Join(gOpt.Roles, ","))
+ nodesToRestart = strings.Join(gOpt.Nodes, ",")
+ rolesToRestart = strings.Join(gOpt.Roles, ",")
+ }
+
+ confirmationMessage := fmt.Sprintf("Will restart the cluster %s with nodes: %s roles: %s.\n%s\nDo you want to continue? [y/N]:",
+ color.HiYellowString(name),
+ color.HiYellowString(nodesToRestart),
+ color.HiYellowString(rolesToRestart),
+ availabilityMessage,
+ )
+ if err := tui.PromptForConfirmOrAbortError(confirmationMessage); err != nil {
  return err
  }
  }