drun can execute more complex commands, e.g. small shell scripts

4 files changed, 88 insertions, 61 deletions

diff --git a/internal/config/common.go b/internal/config/common.go
index 8c07710..f0f1a94 100644
--- a/internal/config/common.go
+++ b/internal/config/common.go
@@ -2,27 +2,19 @@ package config
 
 // CommonConfig stores configuration keys shared by DTail server and client.
 type CommonConfig struct {
-	// The SSH server port number.
-	SSHPort int
-	// Enable experimental features.
+	SSHPort                    int
 	ExperimentalFeaturesEnable bool `json:",omitempty"`
-	// Enable extra debug logging (used for deevlopment or debugging purpes only).
-	DebugEnable bool `json:",omitempty"`
-	// Enable extra trace logging (used for deevlopment or debugging purpes only).
-	TraceEnable bool `json:",omitempty"`
+	DebugEnable                bool `json:",omitempty"`
+	TraceEnable                bool `json:",omitempty"`
 	// The log strategy to use, one of
 	//   stdout: only log to stdout (useful when used with systemd)
 	//   daily: create a log file for every day
-	LogStrategy string
-	// The log directory
-	LogDir string
-	// The cache directory
-	CacheDir string
-	// Do we want to enable pperf http server?
-	PProfEnable bool `json:",omitempty"`
-	// The HTTP port used by PProf
-	PProfPort int `json:",omitempty"`
-	// The PProf HTTP server bind address
+	LogStrategy      string
+	LogDir           string
+	CacheDir         string
+	TmpDir           string `json:",omitempty"`
+	PProfEnable      bool   `json:",omitempty"`
+	PProfPort        int    `json:",omitempty"`
 	PProfBindAddress string `json:",omitempty"`
 }
 
@@ -35,6 +27,7 @@ func newDefaultCommonConfig() *CommonConfig {
 		ExperimentalFeaturesEnable: false,
 		LogDir:                     "log",
 		CacheDir:                   "cache",
+		TmpDir:                     "/tmp",
 		PProfEnable:                false,
 		PProfPort:                  6060,
 		PProfBindAddress:           "0.0.0.0",
diff --git a/internal/io/run/run.go b/internal/io/run/run.go
index 3cf7935..5951cde 100644
--- a/internal/io/run/run.go
+++ b/internal/io/run/run.go
@@ -14,16 +14,16 @@ import (
 
 // Run is for execute a command.
 type Run struct {
-	commandPath string
-	args        []string
-	cmd         *exec.Cmd
+	command string
+	args    []string
+	cmd     *exec.Cmd
 }
 
 // New returns a new command runner.
-func New(commandPath string, args []string) Run {
+func New(command string, args []string) Run {
 	return Run{
-		commandPath: commandPath,
-		args:        args,
+		command: command,
+		args:    args,
 	}
 }
 
@@ -36,11 +36,11 @@ func (r Run) Start(ctx context.Context, lines chan<- line.Line) (pid int, ec int
 	pid = -1
 
 	if len(r.args) > 0 {
-		logger.Debug(r.commandPath, r.args, " ")
-		r.cmd = exec.CommandContext(ctx, r.commandPath, r.args...)
+		logger.Debug(r.command, r.args, " ")
+		r.cmd = exec.CommandContext(ctx, r.command, r.args...)
 	} else {
-		logger.Debug(r.commandPath)
-		r.cmd = exec.CommandContext(ctx, r.commandPath)
+		logger.Debug(r.command)
+		r.cmd = exec.CommandContext(ctx, r.command)
 	}
 
 	stdoutPipe, myErr := r.cmd.StdoutPipe()
@@ -60,8 +60,10 @@ func (r Run) Start(ctx context.Context, lines chan<- line.Line) (pid int, ec int
 		return
 	}
 
-	pid = r.cmd.Process.Pid
-	ec = 0
+	if r.cmd.Process != nil {
+		pid = r.cmd.Process.Pid
+		ec = 0
+	}
 
 	var wg sync.WaitGroup
 	wg.Add(2)
diff --git a/internal/server/handlers/runcommand.go b/internal/server/handlers/runcommand.go
index b7fbb8b..9dc878f 100644
--- a/internal/server/handlers/runcommand.go
+++ b/internal/server/handlers/runcommand.go
@@ -3,9 +3,13 @@ package handlers
 import (
 	"context"
 	"fmt"
+	"io/ioutil"
+	"os"
 	"os/exec"
 	"strings"
+	"time"
 
+	"github.com/mimecast/dtail/internal/config"
 	"github.com/mimecast/dtail/internal/io/logger"
 	"github.com/mimecast/dtail/internal/io/run"
 )
@@ -26,39 +30,66 @@ func (r runCommand) Start(ctx context.Context, argc int, args []string) {
 		r.server.sendServerMessage(logger.Warn(r.server.user, commandParseWarning, args, argc))
 		return
 	}
-	commands := strings.Split(strings.Join(args[1:], " "), ";")
-	r.start(ctx, commands)
+
+	command := strings.Join(args[1:], " ")
+	if strings.Contains(command, ";") {
+		r.startScript(ctx, command)
+		return
+	}
+
+	r.start(ctx, strings.TrimSpace(command))
 }
 
-func (r runCommand) start(ctx context.Context, commands []string) {
-	for _, command := range commands {
-		command = strings.TrimSpace(command)
-		if len(command) == 0 {
-			continue
-		}
-		splitted := strings.Split(command, " ")
-		path := splitted[0]
-		args := splitted[1:]
-
-		qualifiedPath, err := exec.LookPath(path)
-		if err != nil {
-			logger.Error(r.server.user, err)
-			r.server.sendServerMessage(logger.Error(r.server.user, "Unable to execute command(s), check server logs"))
-			r.server.sendServerMessage(".run exitstatus 255")
-			return
-		}
-
-		if !r.server.user.HasFilePermission(qualifiedPath, "runcommands") {
-			logger.Error(r.server.user, "No permission to execute path", qualifiedPath)
-			r.server.sendServerMessage(logger.Error(r.server.user, "Unable to execute command(s), check server logs"))
-			r.server.sendServerMessage(".run exitstatus 255")
-			return
-		}
-
-		r.run = run.New(qualifiedPath, args)
-		pid, ec, _ := r.run.Start(ctx, r.server.lines)
-
-		r.server.sendServerMessage(fmt.Sprintf(".run exitstatus %d", ec))
-		r.server.sendServerMessage(logger.Info(fmt.Sprintf("Process %d exited with status %d", pid, ec)))
+func (r runCommand) startScript(ctx context.Context, script string) {
+	if _, err := os.Stat(config.Common.TmpDir); os.IsNotExist(err) {
+		logger.Error(r.server.user, err)
+		r.server.sendServerMessage(logger.Error(r.server.user, "Unable to execute command(s), check server logs"))
+		return
+	}
+
+	timestamp := time.Now().UnixNano()
+	scriptPath := fmt.Sprintf("%s/%s_%v.sh", config.Common.TmpDir, r.server.user.Name, timestamp)
+
+	// TODO: On dserver startup delete all previously written scripts (there might be left overs due to a crash or so)
+	logger.Debug(r.server.user, "Writing temp script", scriptPath)
+
+	script = fmt.Sprintf("#!/bin/sh\n%s", script)
+	if err := ioutil.WriteFile(scriptPath, []byte(script), 0700); err != nil {
+		logger.Error(r.server.user, err)
+		r.server.sendServerMessage(logger.Error(r.server.user, "Unable to execute command(s), check server logs"))
+		return
 	}
+
+	r.start(ctx, scriptPath)
+	os.Remove(scriptPath)
+}
+
+func (r runCommand) start(ctx context.Context, command string) {
+	if len(command) == 0 {
+		return
+	}
+	splitted := strings.Split(command, " ")
+	path := splitted[0]
+	args := splitted[1:]
+
+	qualifiedPath, err := exec.LookPath(path)
+	if err != nil {
+		logger.Error(r.server.user, err)
+		r.server.sendServerMessage(logger.Error(r.server.user, "Unable to execute command(s), check server logs"))
+		r.server.sendServerMessage(".run exitstatus 255")
+		return
+	}
+
+	if !r.server.user.HasFilePermission(qualifiedPath, "runcommands") {
+		logger.Error(r.server.user, "No permission to execute path", qualifiedPath)
+		r.server.sendServerMessage(logger.Error(r.server.user, "Unable to execute command(s), check server logs"))
+		r.server.sendServerMessage(".run exitstatus 255")
+		return
+	}
+
+	r.run = run.New(qualifiedPath, args)
+	pid, ec, _ := r.run.Start(ctx, r.server.lines)
+
+	r.server.sendServerMessage(fmt.Sprintf(".run exitstatus %d", ec))
+	r.server.sendServerMessage(logger.Info(fmt.Sprintf("Process %d exited with status %d", pid, ec)))
 }
diff --git a/samples/dtail.json.sample b/samples/dtail.json.sample
index 83925c6..4f672e9 100644
--- a/samples/dtail.json.sample
+++ b/samples/dtail.json.sample
@@ -29,6 +29,7 @@
   "Common": {
     "LogDir" : "log",
     "CacheDir" : "cache",
+    "TmpDir" : "tmp",
     "LogStrategy": "stdout",
     "SSHPort": 2222,
     "DebugEnable": false,