cluster: support using provided topo file besides editing it while calling edit-config, add show-config command

components/cluster/command/edit_config.go

@@ -14,10 +14,12 @@
 package command
 
 import (
+	"github.com/pingcap/tiup/pkg/cluster/manager"
 	"github.com/spf13/cobra"
 )
 
 func newEditConfigCmd() *cobra.Command {
+	opt := manager.EditConfigOptions{}
 	cmd := &cobra.Command{
 		Use:   "edit-config <cluster-name>",
 		Short: "Edit TiDB cluster config.\nWill use editor from environment variable `EDITOR`, default use vi",
@@ -30,9 +32,11 @@ func newEditConfigCmd() *cobra.Command {
 			clusterReport.ID = scrubClusterName(clusterName)
 			teleCommand = append(teleCommand, scrubClusterName(clusterName))
 
-			return cm.EditConfig(clusterName, skipConfirm)
+			return cm.EditConfig(clusterName, opt, skipConfirm)
 		},
 	}
 
+	cmd.Flags().StringVarP(&opt.NewTopoFile, "topology-file", "", opt.NewTopoFile, "Use provided topology file to substitute the original one instead of editing it.")
+
 	return cmd
 }

components/cluster/command/root.go

@@ -195,6 +195,7 @@ func init() {
 		newAuditCmd(),
 		newImportCmd(),
 		newEditConfigCmd(),
+		newShowConfigCmd(),
 		newReloadCmd(),
 		newPatchCmd(),
 		newRenameCmd(),

components/cluster/command/show_config.go

@@ -0,0 +1,38 @@
+// Copyright 2021 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package command
+
+import (
+	"github.com/spf13/cobra"
+)
+
+func newShowConfigCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "show-config <cluster-name>",
+		Short: "Show TiDB cluster config",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if len(args) != 1 {
+				return cmd.Help()
+			}
+
+			clusterName := args[0]
+			clusterReport.ID = scrubClusterName(clusterName)
+			teleCommand = append(teleCommand, scrubClusterName(clusterName))
+
+			return cm.ShowConfig(clusterName)
+		},
+	}
+
+	return cmd
+}

components/dm/command/edit_config.go

@@ -14,10 +14,12 @@
 package command
 
 import (
+	"github.com/pingcap/tiup/pkg/cluster/manager"
 	"github.com/spf13/cobra"
 )
 
 func newEditConfigCmd() *cobra.Command {
+	opt := manager.EditConfigOptions{}
 	cmd := &cobra.Command{
 		Use:   "edit-config <cluster-name>",
 		Short: "Edit DM cluster config",
@@ -28,9 +30,11 @@ func newEditConfigCmd() *cobra.Command {
 
 			clusterName := args[0]
 
-			return cm.EditConfig(clusterName, skipConfirm)
+			return cm.EditConfig(clusterName, opt, skipConfirm)
 		},
 	}
 
+	cmd.Flags().StringVarP(&opt.NewTopoFile, "topology-file", "", opt.NewTopoFile, "Use provided topology file to substitute the original one instead of editing it.")
+
 	return cmd
 }

pkg/cluster/manager/edit_config.go

@@ -31,8 +31,13 @@ import (
 	"gopkg.in/yaml.v2"
 )
 
+// EditConfigOptions contains the options for config edition.
+type EditConfigOptions struct {
+	NewTopoFile string // path to new topology file to substitute the original one
+}
+
 // EditConfig lets the user edit the cluster's config.
-func (m *Manager) EditConfig(name string, skipConfirm bool) error {
+func (m *Manager) EditConfig(name string, opt EditConfigOptions, skipConfirm bool) error {
 	if err := clusterutil.ValidateClusterNameOrError(name); err != nil {
 		return err
 	}
@@ -49,7 +54,7 @@ func (m *Manager) EditConfig(name string, skipConfirm bool) error {
 		return perrs.AddStack(err)
 	}
 
-	newTopo, err := m.editTopo(topo, data, skipConfirm)
+	newTopo, err := m.editTopo(topo, data, opt, skipConfirm)
 	if err != nil {
 		return err
 	}
@@ -69,34 +74,40 @@ func (m *Manager) EditConfig(name string, skipConfirm bool) error {
 	return nil
 }
 
+// If the flag --topology-file is specified, the first 2 steps will be skipped.
 // 1. Write Topology to a temporary file.
 // 2. Open file in editor.
 // 3. Check and update Topology.
 // 4. Save meta file.
-func (m *Manager) editTopo(origTopo spec.Topology, data []byte, skipConfirm bool) (spec.Topology, error) {
-	file, err := os.CreateTemp(os.TempDir(), "*")
-	if err != nil {
-		return nil, perrs.AddStack(err)
-	}
+func (m *Manager) editTopo(origTopo spec.Topology, data []byte, opt EditConfigOptions, skipConfirm bool) (spec.Topology, error) {
+	var name string
+	if opt.NewTopoFile == "" {
+		file, err := os.CreateTemp(os.TempDir(), "*")
+		if err != nil {
+			return nil, perrs.AddStack(err)
+		}
 
-	name := file.Name()
+		name = file.Name()
 
-	_, err = io.Copy(file, bytes.NewReader(data))
-	if err != nil {
-		return nil, perrs.AddStack(err)
-	}
+		_, err = io.Copy(file, bytes.NewReader(data))
+		if err != nil {
+			return nil, perrs.AddStack(err)
+		}
 
-	err = file.Close()
-	if err != nil {
-		return nil, perrs.AddStack(err)
-	}
+		err = file.Close()
+		if err != nil {
+			return nil, perrs.AddStack(err)
+		}
 
-	err = utils.OpenFileInEditor(name)
-	if err != nil {
-		return nil, err
+		err = utils.OpenFileInEditor(name)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		name = opt.NewTopoFile
 	}
 
-	// Now user finish editing the file.
+	// Now user finish editing the file or user has provided the new topology file
 	newData, err := os.ReadFile(name)
 	if err != nil {
 		return nil, perrs.AddStack(err)
@@ -107,8 +118,10 @@ func (m *Manager) editTopo(origTopo spec.Topology, data []byte, skipConfirm bool
 	if err != nil {
 		fmt.Print(color.RedString("New topology could not be saved: "))
 		log.Infof("Failed to parse topology file: %v", err)
-		if pass, _ := tui.PromptForConfirmNo("Do you want to continue editing? [Y/n]: "); !pass {
-			return m.editTopo(origTopo, newData, skipConfirm)
+		if opt.NewTopoFile == "" {
+			if pass, _ := tui.PromptForConfirmNo("Do you want to continue editing? [Y/n]: "); !pass {
+				return m.editTopo(origTopo, newData, opt, skipConfirm)
+			}
 		}
 		log.Infof("Nothing changed.")
 		return nil, nil
@@ -118,8 +131,10 @@ func (m *Manager) editTopo(origTopo spec.Topology, data []byte, skipConfirm bool
 	if err := utils.ValidateSpecDiff(origTopo, newTopo); err != nil {
 		fmt.Print(color.RedString("New topology could not be saved: "))
 		log.Errorf("%s", err)
-		if pass, _ := tui.PromptForConfirmNo("Do you want to continue editing? [Y/n]: "); !pass {
-			return m.editTopo(origTopo, newData, skipConfirm)
+		if opt.NewTopoFile == "" {
+			if pass, _ := tui.PromptForConfirmNo("Do you want to continue editing? [Y/n]: "); !pass {
+				return m.editTopo(origTopo, newData, opt, skipConfirm)
+			}
 		}
 		log.Infof("Nothing changed.")
 		return nil, nil

pkg/cluster/manager/show_config.go

@@ -0,0 +1,46 @@
+// Copyright 2021 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package manager
+
+import (
+	"errors"
+	"fmt"
+
+	perrs "github.com/pingcap/errors"
+	"github.com/pingcap/tiup/pkg/cluster/clusterutil"
+	"github.com/pingcap/tiup/pkg/meta"
+	"gopkg.in/yaml.v2"
+)
+
+// ShowConfig shows the cluster's config.
+func (m *Manager) ShowConfig(name string) error {
+	if err := clusterutil.ValidateClusterNameOrError(name); err != nil {
+		return err
+	}
+
+	metadata, err := m.meta(name)
+	if err != nil && !errors.Is(perrs.Cause(err), meta.ErrValidate) {
+		return err
+	}
+
+	topo := metadata.GetTopology()
+
+	data, err := yaml.Marshal(topo)
+	if err != nil {
+		return perrs.AddStack(err)
+	}
+
+	fmt.Print(string(data))
+	return nil
+}