Support template command

To provide standard templates and detailed instructions in the template files

Close #1024

components/cluster/command/root.go

@@ -176,6 +176,7 @@ func init() {
 		newPushCmd(),
 		newTestCmd(), // hidden command for test internally
 		newTelemetryCmd(),
+		newTemplateCmd(),
 	)
 }
 

components/cluster/command/template.go

@@ -0,0 +1,64 @@
+// 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 (
+	"fmt"
+	"path"
+
+	"github.com/pingcap/errors"
+	"github.com/pingcap/tiup/embed"
+	"github.com/spf13/cobra"
+)
+
+// TemplateOptions contains the options for print topology template.
+type TemplateOptions struct {
+	Full    bool // print full template
+	MultiDC bool // print template for deploying to multiple data center
+}
+
+func newTemplateCmd() *cobra.Command {
+	opt := TemplateOptions{}
+
+	cmd := &cobra.Command{
+		Use:    "template",
+		Short:  "Print topology template",
+		Hidden: true,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if opt.Full && opt.MultiDC {
+				return errors.New("at most one of 'full' and 'multi-dc' can be specified")
+			}
+			name := "minimal.yaml"
+			if opt.Full {
+				name = "topology.example.yaml"
+			} else if opt.MultiDC {
+				name = "multi-dc.yaml"
+			}
+
+			fp := path.Join("templates", "examples", name)
+			tpl, err := embed.ReadFile(fp)
+			if err != nil {
+				return err
+			}
+
+			fmt.Println(string(tpl))
+			return nil
+		},
+	}
+
+	cmd.Flags().BoolVar(&opt.Full, "full", false, "Print the full topology template for TiDB cluster.")
+	cmd.Flags().BoolVar(&opt.MultiDC, "multi-dc", false, "Print template for deploying to multiple data center.")
+
+	return cmd
+}

components/dm/command/root.go

@@ -143,6 +143,7 @@ please backup your data before process.`,
 		newImportCmd(),
 		newEnableCmd(),
 		newDisableCmd(),
+		newTemplateCmd(),
 	)
 }
 

components/dm/command/template.go

@@ -0,0 +1,56 @@
+// 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 (
+	"fmt"
+	"path"
+
+	"github.com/pingcap/tiup/embed"
+	"github.com/spf13/cobra"
+)
+
+// TemplateOptions contains the options for print topology template.
+type TemplateOptions struct {
+	Full bool // print full template
+}
+
+func newTemplateCmd() *cobra.Command {
+	opt := TemplateOptions{}
+
+	cmd := &cobra.Command{
+		Use:    "template",
+		Short:  "Print topology template",
+		Hidden: true,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			name := "minimal.yaml"
+			if opt.Full {
+				name = "topology.example.yaml"
+			}
+
+			fp := path.Join("templates", "examples", "dm", name)
+			tpl, err := embed.ReadFile(fp)
+			if err != nil {
+				return err
+			}
+
+			fmt.Println(string(tpl))
+			return nil
+		},
+	}
+
+	cmd.Flags().BoolVar(&opt.Full, "full", false, "Print the full topology template for DM cluster.")
+
+	return cmd
+}

examples

@@ -0,0 +1 @@
+embed/templates/examples