switch interactive shell to PTY to support cases like python or neo4j

component/statusbar.go

@@ -34,7 +34,12 @@ func NewStatusLine(configFileName string, palette console.Palette) *StatusBar {
 
 func (s *StatusBar) Draw(buffer *ui.Buffer) {
 	buffer.Fill(ui.NewCell(' ', ui.NewStyle(console.ColorClear, console.MenuColorBackground)), s.GetRect())
-	buffer.SetString(fmt.Sprintf(" %s %s @ %s", console.AppTitle, console.AppVersion, s.configFileName), ui.NewStyle(console.MenuColorText, console.MenuColorBackground), s.Min)
+
+	if false { // TODO check license
+		buffer.SetString(fmt.Sprintf(" %s", console.AppLicenseWarning), ui.NewStyle(console.MenuColorText, console.MenuColorBackground), s.Min)
+	} else {
+		buffer.SetString(fmt.Sprintf(" %s %s @ %s", console.AppTitle, console.AppVersion, s.configFileName), ui.NewStyle(console.MenuColorText, console.MenuColorBackground), s.Min)
+	}
 
 	indent := bindingsIndent
 	for _, binding := range s.keyBindings {

config-interactive-shell.yml

@@ -0,0 +1,29 @@
+variables:
+  PGPASSWORD: fred
+  mongoconnection: mongo --quiet --host=localhost blog
+  mysqlconnection: mysql -u root -s --database mysql --skip-column-names
+  neo4jconnection: cypher-shell -u neo4j -p 121314 --format plain
+  postgresconnection: psql -h localhost -U postgres --no-align --tuples-only
+  sshconnection: ssh -i ~/sqshq.pem ec2-user@3.215.108.82
+textboxes:
+- title: Neo4j
+  position: [[0, 0], [13, 40]]
+  init: $neo4jconnection
+  sample: match (n) return count(n);
+  transform: echo "$sample" | tail -n 1
+- title: Postgres
+  position: [[13, 0], [14, 40]]
+  init: $postgresconnection
+  sample: select random();
+- title: MySQL
+  position: [[27, 0], [14, 40]]
+  init: $mysqlconnection
+  sample: select rand();
+- title: MongoDB
+  position: [[41, 0], [13, 40]]
+  init: $mongoconnection
+  sample: db.getCollection('posts').find({status:'ACTIVE'}).itcount()
+- title: SSH
+  position: [[54, 0], [13, 40]]
+  init: $sshconnection
+  sample: ps -A -o %cpu | awk '{s+=$1} END {print s}'

console/console.go

@@ -14,6 +14,7 @@ const (
 	RowsCount         = 40
 	AppTitle          = "sampler"
 	AppVersion        = "0.9.0"
+	AppLicenseWarning = "UNLICENSED. FOR PERSONAL USE ONLY. VISIT SAMPLER.DEV"
 )
 
 const (

data/item.go

@@ -3,7 +3,9 @@ package data
 import (
 	"bufio"
 	"errors"
+	"fmt"
 	ui "github.com/gizak/termui/v3"
+	"github.com/kr/pty"
 	"github.com/sqshq/sampler/config"
 	"io"
 	"os"
@@ -12,6 +14,8 @@ import (
 	"time"
 )
 
+const interactiveShellStartupTimeout = time.Second
+
 type Item struct {
 	Label            string
 	SampleScript     string
@@ -23,10 +27,9 @@ type Item struct {
 }
 
 type InteractiveShell struct {
-	StdoutCh chan string
+	Channel chan string
-	StderrCh chan string
+	File    io.WriteCloser
-	Stdin    io.WriteCloser
+	Cmd     *exec.Cmd
-	Cmd      *exec.Cmd
 }
 
 func NewItems(cfgs []config.Item, rateMs int) []*Item {
@@ -53,7 +56,7 @@ func (i *Item) nextValue(variables []string) (string, error) {
 	if i.InitScript != nil && i.InteractiveShell == nil {
 		err := i.initInteractiveShell(variables)
 		if err != nil {
-			return "", err
+			return "", errors.New(fmt.Sprintf("Failed to init interactive shell: %s", err))
 		}
 	}
 
@@ -83,84 +86,62 @@ func (i *Item) initInteractiveShell(variables []string) error {
 	cmd := exec.Command("sh", "-c", *i.InitScript)
 	enrichEnvVariables(cmd, variables)
 
-	stdout, err := cmd.StdoutPipe()
+	file, err := pty.Start(cmd)
 	if err != nil {
 		return err
 	}
 
-	stderr, err := cmd.StderrPipe()
+	scanner := bufio.NewScanner(file)
-	if err != nil {
+	channel := make(chan string)
-		return err
-	}
-
-	stdin, err := cmd.StdinPipe()
-	if err != nil {
-		return err
-	}
-
-	stdoutScanner := bufio.NewScanner(stdout)
-	stderrScanner := bufio.NewScanner(stderr)
-
-	stdoutCh := make(chan string)
-	stderrCh := make(chan string)
 
 	go func() {
-		for stdoutScanner.Scan() {
+		for scanner.Scan() {
-			stdoutCh <- stdoutScanner.Text()
+			channel <- scanner.Text()
-			stderrCh <- stderrScanner.Text()
 		}
 	}()
 
 	i.InteractiveShell = &InteractiveShell{
-		StdoutCh: stdoutCh,
+		Channel: channel,
-		StderrCh: stderrCh,
+		File:    file,
-		Stdin:    stdin,
+		Cmd:     cmd,
-		Cmd:      cmd,
 	}
 
-	err = cmd.Start()
+	_, err = file.Read(make([]byte, 4096))
 	if err != nil {
 		return err
 	}
 
+	time.Sleep(interactiveShellStartupTimeout)
+
 	return nil
 }
 
 func (i *Item) executeInteractiveShellCmd(variables []string) (string, error) {
 
-	_, err := io.WriteString(i.InteractiveShell.Stdin, i.SampleScript+"\n")
+	_, err := io.WriteString(i.InteractiveShell.File, fmt.Sprintf(" %s\n", i.SampleScript))
 	if err != nil {
-		return "", err
+		return "", errors.New(fmt.Sprintf("Failed to execute interactive shell cmd: %s", err))
 	}
 
 	timeout := make(chan bool, 1)
 
 	go func() {
-		time.Sleep(time.Duration(i.RateMs / 2))
+		time.Sleep(time.Duration(i.RateMs))
 		timeout <- true
 	}()
 
-	var resultText strings.Builder
+	var outputText strings.Builder
-	var errorText strings.Builder
 
 	for {
 		select {
-		case stdout := <-i.InteractiveShell.StdoutCh:
+		case output := <-i.InteractiveShell.Channel:
-			if len(stdout) > 0 {
+			if !strings.Contains(output, i.SampleScript) && len(output) > 0 {
-				resultText.WriteString(stdout)
+				outputText.WriteString(output)
-				resultText.WriteString("\n")
+				outputText.WriteString("\n")
-			}
-		case stderr := <-i.InteractiveShell.StderrCh:
-			if len(stderr) > 0 {
-				errorText.WriteString(stderr)
-				errorText.WriteString("\n")
 			}
 		case <-timeout:
-			if errorText.Len() > 0 {
+			sample := cleanupOutput(outputText.String())
-				return "", errors.New(errorText.String())
+			return i.transformInteractiveShellCmd(sample)
-			} else {
-				return i.transformInteractiveShellCmd(resultText.String())
-			}
 		}
 	}
 }
@@ -180,3 +161,11 @@ func enrichEnvVariables(cmd *exec.Cmd, variables []string) {
 		cmd.Env = append(cmd.Env, variable)
 	}
 }
+
+func cleanupOutput(output string) string {
+	s := strings.TrimSpace(output)
+	if idx := strings.Index(s, "\r"); idx != -1 {
+		return s[idx+1:]
+	}
+	return s
+}

data/item_test.go

@@ -0,0 +1,25 @@
+package data
+
+import "testing"
+
+func Test_cleanupOutput(t *testing.T) {
+	type args struct {
+		output string
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{"should trim everything before carriage return", args{">>\rtext"}, "text"},
+		{"should trim carriage return at the end", args{"text\r"}, "text"},
+		{"should remove tabs and spaces", args{"\t\t\ntext "}, "text"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := cleanupOutput(tt.args.output); got != tt.want {
+				t.Errorf("cleanupOutput() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

data/sampler.go

@@ -39,7 +39,7 @@ func NewSampler(consumer *Consumer, items []*Item, triggers []*Trigger, options
 			select {
 			case sample := <-sampler.triggersChannel:
 				for _, t := range sampler.triggers {
-					t.Execute(sample)
+					go t.Execute(sample)
 				}
 			}
 		}

go.mod

@@ -5,6 +5,7 @@ require (
 	github.com/hajimehoshi/go-mp3 v0.1.1
 	github.com/hajimehoshi/oto v0.1.1
 	github.com/jessevdk/go-flags v1.4.0
+	github.com/kr/pty v1.1.4
 	github.com/mattn/go-runewidth v0.0.4
 	github.com/mbndr/figlet4go v0.0.0-20190224160619-d6cef5b186ea
 	github.com/mitchellh/go-wordwrap v1.0.0 // indirect

go.sum

@@ -12,6 +12,8 @@ github.com/hajimehoshi/oto v0.1.1 h1:EG+WxxeAfde1mI0adhLYvGbKgDCxm7bCTd6g+JIA6vI
 github.com/hajimehoshi/oto v0.1.1/go.mod h1:hUiLWeBQnbDu4pZsAhOnGqMI1ZGibS6e2qhQdfpwz04=
 github.com/jessevdk/go-flags v1.4.0 h1:4IU2WS7AumrZ/40jfhf4QVDMsQwqA7VEHozFRrGARJA=
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
+github.com/kr/pty v1.1.4 h1:5Myjjh3JY/NaAi4IsUbHADytDyl1VE1Y9PXDlL+P/VQ=
+github.com/kr/pty v1.1.4/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/mattn/go-runewidth v0.0.2/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
 github.com/mattn/go-runewidth v0.0.4 h1:2BvfKmzob6Bmd4YsL0zygOqfdFnK7GR4QL06Do4/p7Y=
 github.com/mattn/go-runewidth v0.0.4/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=

main.go

@@ -15,6 +15,7 @@ import (
 	"github.com/sqshq/sampler/console"
 	"github.com/sqshq/sampler/data"
 	"github.com/sqshq/sampler/event"
+	"time"
 )
 
 type Starter struct {
@@ -30,6 +31,7 @@ func (s *Starter) start(drawable ui.Drawable, consumer *data.Consumer, component
 	items := data.NewItems(itemsConfig, *componentConfig.RateMs)
 	data.NewSampler(consumer, items, triggers, s.opt, s.cfg.Variables, *componentConfig.RateMs)
 	s.lout.AddComponent(cpt)
+	time.Sleep(100 * time.Millisecond) // desync coroutines
 }
 
 func main() {