1 files changed, 164 insertions, 0 deletions
diff --git a/gopls/internal/lsp/cmd/remote.go b/gopls/internal/lsp/cmd/remote.go
new file mode 100644
index 000000000..684981cff
--- /dev/null
+++ b/gopls/internal/lsp/cmd/remote.go
@@ -0,0 +1,164 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cmd
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+
+	"golang.org/x/tools/gopls/internal/lsp/command"
+	"golang.org/x/tools/gopls/internal/lsp/lsprpc"
+)
+
+type remote struct {
+	app *Application
+	subcommands
+
+	// For backward compatibility, allow aliasing this command (it was previously
+	// called 'inspect').
+	//
+	// TODO(rFindley): delete this after allowing some transition time in case
+	//                 there were any users of 'inspect' (I suspect not).
+	alias string
+}
+
+func newRemote(app *Application, alias string) *remote {
+	return &remote{
+		app: app,
+		subcommands: subcommands{
+			&listSessions{app: app},
+			&startDebugging{app: app},
+		},
+		alias: alias,
+	}
+}
+
+func (r *remote) Name() string {
+	if r.alias != "" {
+		return r.alias
+	}
+	return "remote"
+}
+
+func (r *remote) Parent() string { return r.app.Name() }
+
+func (r *remote) ShortHelp() string {
+	short := "interact with the gopls daemon"
+	if r.alias != "" {
+		short += " (deprecated: use 'remote')"
+	}
+	return short
+}
+
+// listSessions is an inspect subcommand to list current sessions.
+type listSessions struct {
+	app *Application
+}
+
+func (c *listSessions) Name() string   { return "sessions" }
+func (c *listSessions) Parent() string { return c.app.Name() }
+func (c *listSessions) Usage() string  { return "" }
+func (c *listSessions) ShortHelp() string {
+	return "print information about current gopls sessions"
+}
+
+const listSessionsExamples = `
+Examples:
+
+1) list sessions for the default daemon:
+
+$ gopls -remote=auto remote sessions
+or just
+$ gopls remote sessions
+
+2) list sessions for a specific daemon:
+
+$ gopls -remote=localhost:8082 remote sessions
+`
+
+func (c *listSessions) DetailedHelp(f *flag.FlagSet) {
+	fmt.Fprint(f.Output(), listSessionsExamples)
+	printFlagDefaults(f)
+}
+
+func (c *listSessions) Run(ctx context.Context, args ...string) error {
+	remote := c.app.Remote
+	if remote == "" {
+		remote = "auto"
+	}
+	state, err := lsprpc.QueryServerState(ctx, remote)
+	if err != nil {
+		return err
+	}
+	v, err := json.MarshalIndent(state, "", "\t")
+	if err != nil {
+		log.Fatal(err)
+	}
+	os.Stdout.Write(v)
+	return nil
+}
+
+type startDebugging struct {
+	app *Application
+}
+
+func (c *startDebugging) Name() string  { return "debug" }
+func (c *startDebugging) Usage() string { return "[host:port]" }
+func (c *startDebugging) ShortHelp() string {
+	return "start the debug server"
+}
+
+const startDebuggingExamples = `
+Examples:
+
+1) start a debug server for the default daemon, on an arbitrary port:
+
+$ gopls -remote=auto remote debug
+or just
+$ gopls remote debug
+
+2) start for a specific daemon, on a specific port:
+
+$ gopls -remote=localhost:8082 remote debug localhost:8083
+`
+
+func (c *startDebugging) DetailedHelp(f *flag.FlagSet) {
+	fmt.Fprint(f.Output(), startDebuggingExamples)
+	printFlagDefaults(f)
+}
+
+func (c *startDebugging) Run(ctx context.Context, args ...string) error {
+	if len(args) > 1 {
+		fmt.Fprintln(os.Stderr, c.Usage())
+		return errors.New("invalid usage")
+	}
+	remote := c.app.Remote
+	if remote == "" {
+		remote = "auto"
+	}
+	debugAddr := ""
+	if len(args) > 0 {
+		debugAddr = args[0]
+	}
+	debugArgs := command.DebuggingArgs{
+		Addr: debugAddr,
+	}
+	var result command.DebuggingResult
+	if err := lsprpc.ExecuteCommand(ctx, remote, command.StartDebugging.ID(), debugArgs, &result); err != nil {
+		return err
+	}
+	if len(result.URLs) == 0 {
+		return errors.New("no debugging URLs")
+	}
+	for _, url := range result.URLs {
+		fmt.Printf("debugging on %s\n", url)
+	}
+	return nil
+}