Support auto-completion for bash and powershell

README.md

@@ -49,6 +49,40 @@ Then copy the `./bin/swctl-latest-(darwin|linux|windows)-amd64` to your `PATH` d
 
 You can also copy it to any directory you like, then add that directory to `PATH`. **We recommend you to rename the `swctl-latest-(darwin|linux|windows)-amd64` to `swctl`.**
 
+## Autocompletion
+
+`swctl` provides auto-completion support for bash and powershell, which can save you a lot of typing.
+
+### Bash
+
+The swctl completion script for bash can be generated with the command `swctl completion bash`. Sourcing the completion script in your shell enables swctl auto-completion:
+
+```shell
+swctl completion bash > bash_autocomplete &&
+    sudo cp ./bash_autocomplete /etc/bash_completion.d/swctl &&
+    echo >> ~/.bashrc &&
+    echo "export PROG=swctl" >> ~/.bashrc
+```
+
+After reloading your shell, swctl auto-completion should be working.
+
+### powershell
+
+Similarly, run the following command in your powershell terminal to enable auto-completion:
+
+```shell 
+set-executionpolicy remotesigned -Scope CurrentUser
+swctl completion powershell >> $profile
+```
+
+If you get an error like `OpenError: (:) [Out-File], DirectoryNotFoundException`, then you need to run the following command to create `$profile` file:
+
+```shell
+New-Item -Type file -Force $profile
+```
+
+After reloading your shell, swctl auto-completion should be working.
+
 
 # Commands
 Commands in SkyWalking CLI are organized into two levels, in the form of `swctl --option <level1> --option <level2> --option`,

cmd/swctl/main.go

@@ -21,6 +21,7 @@ import (
 	"io/ioutil"
 	"os"
 
+	"github.com/apache/skywalking-cli/internal/commands/completion"
 	"github.com/apache/skywalking-cli/internal/commands/dashboard"
 	"github.com/apache/skywalking-cli/internal/commands/dependency"
 	"github.com/apache/skywalking-cli/internal/commands/endpoint"
@@ -125,6 +126,7 @@ func main() {
 		event.Command,
 		logs.Command,
 		profile.Command,
+		completion.Command,
 		dependency.Command,
 	}
 
@@ -137,6 +139,12 @@ func main() {
 	app.Flags = flags
 	app.CommandNotFound = util.CommandNotFound
 
+	// Enable auto-completion.
+	app.EnableBashCompletion = true
+	cli.BashCompletionFlag = cli.BoolFlag{
+		Name:   "auto_complete",
+		Hidden: true,
+	}
 	if err := app.Run(os.Args); err != nil {
 		log.Fatalln(err)
 	}

internal/commands/completion/bash.go

@@ -0,0 +1,58 @@
+// Licensed to Apache Software Foundation (ASF) under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Apache Software Foundation (ASF) licenses this file to you 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, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package completion
+
+import (
+	"fmt"
+
+	"github.com/urfave/cli"
+)
+
+var bashCommand = cli.Command{
+	Name:      "bash",
+	Aliases:   []string{"b"},
+	Usage:     "Output shell completion code for bash",
+	ArgsUsage: "[parameters...]",
+	Action: func(ctx *cli.Context) error {
+		fmt.Print(bashScript)
+		return nil
+	},
+}
+
+const bashScript = `
+: ${PROG:=$(basename ${BASH_SOURCE})}
+
+_cli_bash_autocomplete() {
+  if [[ "${COMP_WORDS[0]}" != "source" ]]; then
+    local cur opts base
+    COMPREPLY=()
+    cur="${COMP_WORDS[COMP_CWORD]}"
+    if [[ "$cur" == "-"* ]]; then
+      opts=$( ${COMP_WORDS[@]:0:$COMP_CWORD} ${cur} --auto_complete )
+    else
+      opts=$( ${COMP_WORDS[@]:0:$COMP_CWORD} --auto_complete )
+    fi
+    COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
+    return 0
+  fi
+}
+
+complete -o bashdefault -o default -o nospace -F _cli_bash_autocomplete $PROG
+unset PROG
+
+`

internal/commands/completion/completion.go

@@ -0,0 +1,31 @@
+// Licensed to Apache Software Foundation (ASF) under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Apache Software Foundation (ASF) licenses this file to you 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, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package completion
+
+import (
+	"github.com/urfave/cli"
+)
+
+var Command = cli.Command{
+	Name:  "completion",
+	Usage: "Output shell completion code for bash and powershell",
+	Subcommands: []cli.Command{
+		bashCommand,
+		powershellCommand,
+	},
+}

internal/commands/completion/powershell.go

@@ -0,0 +1,71 @@
+// Licensed to Apache Software Foundation (ASF) under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Apache Software Foundation (ASF) licenses this file to you 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, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package completion
+
+import (
+	"fmt"
+
+	"github.com/urfave/cli"
+)
+
+var powershellCommand = cli.Command{
+	Name:      "powershell",
+	Aliases:   []string{"p"},
+	Usage:     "Output shell completion code for powershell",
+	ArgsUsage: "[parameters...]",
+	Action: func(ctx *cli.Context) error {
+		fmt.Print(powershellScript)
+		return nil
+	},
+}
+
+const powershellScript = `
+Register-ArgumentCompleter -Native -CommandName swctl -ScriptBlock {
+	param($commandName, $commands, $cursorPosition)
+
+	$match = $($(complete $commands $cursorPosition) -split " ")
+	# Output matched commands one by one.
+	for($i=0; $i -lt ($match.Length-1); $i+=1){
+		  Write-Output $match[$i]
+	}
+}
+# Find all matching commands.
+function complete($commands, $cursorPosition){
+	# Get command line parameters.
+	$parameters = $($commands -split " ")
+	# Uncompleted parameters.
+	$uncomplete = $parameters[-1]
+
+	# Get the parameters before $uncomplete.
+	$len = $parameters.Length-2
+	if ("$commands".Length -ne $cursorPosition) { return "" }
+	$beforeCommands = $parameters[0..($len)]
+
+	# Find the command prefixed with $uncomplete.
+	$match = ""
+	Invoke-Expression "$beforeCommands --auto_complete" | ForEach-Object {
+		  $flag = 1
+		  for ($i=0; $i -lt $uncomplete.Length; $i = $i +1){
+				if ($_[$i] -ne $uncomplete[$i]) { $flag = 0 }
+		  }
+		  if ($flag -eq 1) {  $match+="$_ " }
+	}
+	return $match
+}
+
+`