manager: check for global configs and prompt user for confirmation on…

… scale-out

pkg/cluster/manager/scale_out.go

@@ -31,6 +31,7 @@ import (
 	"github.com/pingcap/tiup/pkg/logger/log"
 	"github.com/pingcap/tiup/pkg/set"
 	"github.com/pingcap/tiup/pkg/utils"
+	"gopkg.in/yaml.v3"
 )
 
 // ScaleOut scale out the cluster.
@@ -47,6 +48,12 @@ func (m *Manager) ScaleOut(
 		return err
 	}
 
+	// check for the input topology to let user confirm if there're any
+	// global configs set
+	if err := checkForGlobalConfigs(topoFile); err != nil {
+		return err
+	}
+
 	metadata, err := m.meta(name)
 	// allow specific validation errors so that user can recover a broken
 	// cluster if it is somehow in a bad state.
@@ -57,6 +64,7 @@ func (m *Manager) ScaleOut(
 
 	topo := metadata.GetTopology()
 	base := metadata.GetBaseMeta()
+
 	// Inherit existing global configuration. We must assign the inherited values before unmarshalling
 	// because some default value rely on the global options and monitored options.
 	newPart := topo.NewPart()
@@ -168,3 +176,35 @@ func validateNewTopo(topo spec.Topology) (err error) {
 	})
 	return err
 }
+
+// checkForGlobalConfigs checks the input scale out topology to make sure users are aware
+// of the global config fields in it will be ignored.
+func checkForGlobalConfigs(topoFile string) error {
+	yamlFile, err := spec.ReadYamlFile(topoFile)
+	if err != nil {
+		return err
+	}
+
+	var newPart map[string]interface{}
+	if err := yaml.Unmarshal(yamlFile, &newPart); err != nil {
+		return err
+	}
+
+	for k := range newPart {
+		switch k {
+		case "global",
+			"monitored",
+			"server_configs":
+			log.Warnf(
+				`You have one or more of ["global", "monitored", "server_configs"] fields configured in
+the scale out topology, but they will be ignored during the scaling out process.
+If you want to use configs different from the existing cluster, cancel now and
+set them in the specification fileds for each host.`)
+			if err := cliutil.PromptForConfirmOrAbortError("Do you want to continue? [y/N]: "); err != nil {
+				return err
+			}
+			return nil // user confirmed, skip futher checks
+		}
+	}
+	return nil
+}

pkg/cluster/spec/parse_topology.go

@@ -35,17 +35,15 @@ var (
 	ErrTopologyParseFailed = errNSTopolohy.NewType("parse_failed", errutil.ErrTraitPreCheck)
 )
 
-// ParseTopologyYaml read yaml content from `file` and unmarshal it to `out`
-func ParseTopologyYaml(file string, out Topology) error {
+// ReadYamlFile read yaml content from file`
+func ReadYamlFile(file string) ([]byte, error) {
 	suggestionProps := map[string]string{
 		"File": file,
 	}
 
-	zap.L().Debug("Parse topology file", zap.String("file", file))
-
 	yamlFile, err := os.ReadFile(file)
 	if err != nil {
-		return ErrTopologyReadFailed.
+		return nil, ErrTopologyReadFailed.
 			Wrap(err, "Failed to read topology file %s", file).
 			WithProperty(cliutil.SuggestionFromTemplate(`
 Please check whether your topology file {{ColorKeyword}}{{.File}}{{ColorReset}} exists and try again.
@@ -54,6 +52,21 @@ To generate a sample topology file:
   {{ColorCommand}}{{OsArgs0}} template topology > topo.yaml{{ColorReset}}
 `, suggestionProps))
 	}
+	return yamlFile, nil
+}
+
+// ParseTopologyYaml read yaml content from `file` and unmarshal it to `out`
+func ParseTopologyYaml(file string, out Topology) error {
+	suggestionProps := map[string]string{
+		"File": file,
+	}
+
+	zap.L().Debug("Parse topology file", zap.String("file", file))
+
+	yamlFile, err := ReadYamlFile(file)
+	if err != nil {
+		return err
+	}
 
 	if err = yaml.UnmarshalStrict(yamlFile, out); err != nil {
 		return ErrTopologyParseFailed.