Add feature: harp console

README.md

@@ -77,6 +77,11 @@ harp -h
 
 # Run arbitrary Go program wihtout harp.json
 harp -server app@test.com:8022 -t run app.go # with default -goos=linux -goarch=amd64
+
+# Run shell commands or execute scripts with harp console (alias: sh, shell)
+harp -s prod console
+harp -s prod console < my-shell-script
+harp -s prod console <<<(ls)
 ```
 
 ## Common Trouble Shootings
@@ -153,6 +158,8 @@ example:
 }
 ```
 
+## Usages
+
 ### How to specify server or server sets:
 
 Using the configuration above as example, server set means the key in `Servers` object value, i.e. `prod`, `dev`.
@@ -425,3 +432,18 @@ harp xc
 ```
 
 Note: before using `harp xc`, you need to enable cross compilation by installing go from source, details could be found here: https://golang.org/doc/install/source
+
+### Console (sh, shell)
+
+Run shell commands or execute scripts with harp console (alias: sh, shell)
+
+```
+# start a repl to execute shell commands
+harp -s prod console
+
+# run a script
+harp -s prod console < my-shell-script
+
+# another example
+harp -s prod console <<<(ls)
+```

console.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+	"sync"
+
+	"github.com/chzyer/readline"
+)
+
+func startConsole(servers []*Server) {
+	rl, err := readline.New("> ")
+	if err != nil {
+		panic(err)
+	}
+	defer rl.Close()
+
+	type output struct {
+		serv   *Server
+		output string
+	}
+
+	isTerminal := readline.IsTerminal(int(os.Stdin.Fd()))
+	for {
+		var line string
+		var err error
+		if isTerminal {
+			line, err = rl.Readline()
+		} else {
+			lineb, er := ioutil.ReadAll(os.Stdin)
+			line, err = string(lineb), er
+		}
+		if err != nil { // io.EOF
+			break
+		}
+
+		outputc := make(chan output)
+		var mutex sync.Mutex
+		var count int
+		var wg sync.WaitGroup
+		wg.Add(1)
+		go func() {
+			for {
+				mutex.Lock()
+				output := <-outputc
+				prompt := output.serv.prompt()
+				if isTerminal {
+					prompt += " " + line
+				}
+				if count > 0 && strings.TrimSpace(output.output) != "" {
+					prompt = "\n" + prompt
+				}
+				fmt.Println(prompt)
+				if strings.TrimSpace(output.output) != "" {
+					fmt.Printf(output.output)
+				}
+				if count++; count >= len(servers) {
+					break
+				}
+				mutex.Unlock()
+			}
+			wg.Done()
+		}()
+
+		for _, serv := range servers {
+			wg.Add(1)
+			go func(serv *Server) {
+				outputc <- output{serv: serv, output: serv.exec(line)}
+				wg.Done()
+			}(serv)
+		}
+		wg.Wait()
+
+		if !isTerminal {
+			return
+		}
+	}
+}

harp.go

@@ -108,6 +108,9 @@ type App struct {
 	DeployScript    string
 	RestartScript   string
 	MigrationScript string
+
+	// TODO
+	// Hooks struct{}
 }
 
 type Tasks []string
@@ -127,6 +130,7 @@ func (t *FlagStrings) Set(s string) error {
 }
 
 var (
+	// option is a global control center, keeping flags in one place.
 	option = struct {
 		configPath string
 
@@ -160,11 +164,18 @@ var (
 		deploy string
 
 		tasks Tasks
-		hand  bool
+		hand  bool // hand flag indicates migration are executed but only deployed on servers
 
-		cli bool
+		// cli bool
 
+		// transient flag allow running go program without the presence of harp.json
 		transient bool
+
+		hook struct {
+			before, after string
+		}
+
+		docker bool
 	}{}
 
 	migrations []Migration
@@ -309,6 +320,8 @@ func main() {
 		}
 	case "cross-compile", "xc":
 		initXC()
+	case "console", "shell", "sh":
+		startConsole(servers)
 	default:
 		fmt.Println("unknown command:", args[0])
 		os.Exit(1)

server.go

@@ -22,7 +22,9 @@ import (
 type Server struct {
 	ID string
 
-	Envs   map[string]string
+	Envs map[string]string
+	// Args   []string // TODO: support
+
 	Home   string
 	GoPath string
 	LogDir string
@@ -32,6 +34,9 @@ type Server struct {
 	Host string
 	Port string
 
+	// TODO
+	Password string
+
 	Set string // aka, Type
 
 	client *ssh.Client
@@ -258,6 +263,7 @@ func (s *Server) restartScript() (script string) {
 	}
 	args := strings.Join(app.Args, " ")
 	script += fmt.Sprintf("cd %s/src/%s\n", s.GoPath, app.ImportPath)
+	// env=val nohup $GOPATH/bin/$app arg1 >> $log 2&1 &
 	script += fmt.Sprintf("%s nohup %s/bin/%s %s >> %s 2>&1 &\n", envs, s.GoPath, app.Name, args, log)
 	script += fmt.Sprintf("echo $! > %s\n", pid)
 	script += "cd " + s.Home
@@ -437,6 +443,25 @@ func (s *Server) getSession() *ssh.Session {
 	return session
 }
 
+func (s *Server) exec(cmd string) string {
+	if s.client == nil {
+		s.initClient()
+	}
+
+	session, err := s.client.NewSession()
+	if err != nil {
+		// fmt.Printf("%s: %s\n", s, err)
+		return err.Error()
+	}
+
+	output, err := session.CombinedOutput(cmd)
+	if err != nil {
+		output = append([]byte(err.Error()+"\n"), output...)
+	}
+	session.Close()
+	return string(output)
+}
+
 // name@host:port
 func (s Server) String() string {
 	return fmt.Sprintf("%s@%s%s", s.User, s.Host, s.Port)
@@ -545,3 +570,12 @@ func (s *Server) diffFiles() string {
 
 	return diff
 }
+
+func (s *Server) prompt() string {
+	whoami := strings.TrimSpace(s.exec("whoami"))
+	hostname := strings.TrimSpace(s.exec("hostname"))
+	if whoami == "" || hostname == "" {
+		return fmt.Sprintf("%s:%s$", s, s.Home)
+	}
+	return fmt.Sprintf("%s@%s:%s$", whoami, hostname, s.Home)
+}

version.go

@@ -1,3 +1,3 @@
 package main
 
-const version = 15
+const version = 16