From 44e391271cb6a83739ff1be7b9f4eece3df459a0 Mon Sep 17 00:00:00 2001
From: ebarrios <esteban.barrios@trivago.com>
Date: Mon, 16 Dec 2019 17:56:57 +0100
Subject: [PATCH] Set command stanza to optional in the pot driver

---
 driver/driver.go  | 12 +++++++++---
 driver/prepare.go | 20 ++++++++++++++------
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/driver/driver.go b/driver/driver.go
index 9c2e04e..2095eb4 100644
--- a/driver/driver.go
+++ b/driver/driver.go
@@ -54,7 +54,7 @@ var (
 		"image":           hclspec.NewAttr("image", "string", true),
 		"pot":             hclspec.NewAttr("pot", "string", true),
 		"tag":             hclspec.NewAttr("tag", "string", true),
-		"command":         hclspec.NewAttr("command", "string", true),
+		"command":         hclspec.NewAttr("command", "string", false),
 		"args":            hclspec.NewAttr("args", "list(string)", false),
 		"port_map":        hclspec.NewAttr("port_map", "list(map(string))", false),
 		"network_mode":    hclspec.NewAttr("network_mode", "string", false),
@@ -281,7 +281,10 @@ func (d *Driver) RecoverTask(handle *drivers.TaskHandle) error {
 		return fmt.Errorf("failed to decode driver config in RESTORETASK: %v", err)
 	}*/
 
-	se := prepareContainer(handle.Config, driverConfig)
+	se, err := prepareContainer(handle.Config, driverConfig)
+	if err != nil {
+		return err
+	}
 	se.logger = d.logger
 
 	alive := se.checkContainerAlive(handle.Config)
@@ -368,7 +371,10 @@ func (d *Driver) StartTask(cfg *drivers.TaskConfig) (*drivers.TaskHandle, *drive
 	handle := drivers.NewTaskHandle(taskHandleVersion)
 	handle.Config = cfg
 
-	se := prepareContainer(cfg, driverConfig)
+	se, err := prepareContainer(cfg, driverConfig)
+	if err != nil {
+		return nil, nil, err
+	}
 
 	se.logger = d.logger
 	alive := se.checkContainerAlive(cfg)
diff --git a/driver/prepare.go b/driver/prepare.go
index 57926c6..ffe4ba8 100644
--- a/driver/prepare.go
+++ b/driver/prepare.go
@@ -1,6 +1,7 @@
 package pot
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -12,7 +13,7 @@ import (
 )
 
 // prepareContainer preloads the taskcnf into args to be passed to a execCmd
-func prepareContainer(cfg *drivers.TaskConfig, taskCfg TaskConfig) syexec {
+func prepareContainer(cfg *drivers.TaskConfig, taskCfg TaskConfig) (syexec, error) {
 	argv := make([]string, 0, 50)
 	var se syexec
 	se.taskConfig = taskCfg
@@ -28,14 +29,21 @@ func prepareContainer(cfg *drivers.TaskConfig, taskCfg TaskConfig) syexec {
 	}
 
 	if len(taskCfg.Args) > 0 {
+		if taskCfg.Command == "" {
+			err := errors.New("command can not be empty if arguments are provided")
+			fmt.Println("command can not be empty if arguments are provided")
+			return se, err
+		}
+
 		for _, arg := range taskCfg.Args {
 			taskCfg.Command = taskCfg.Command + " " + arg
 		}
 	}
 
-	taskCfg.Command = "\"" + taskCfg.Command + "\""
-	argv = append(argv, "-c", taskCfg.Command)
-
+	if taskCfg.Command != "" {
+		taskCfg.Command = "\"" + taskCfg.Command + "\""
+		argv = append(argv, "-c", taskCfg.Command)
+	}
 	if taskCfg.NetworkMode != "" {
 		argv = append(argv, "-N", taskCfg.NetworkMode)
 	} else if len(taskCfg.PortMap) > 0 {
@@ -54,7 +62,7 @@ func prepareContainer(cfg *drivers.TaskConfig, taskCfg TaskConfig) syexec {
 	completeName := cfg.JobName + cfg.Name
 	argv = append(argv, "-n", completeName, "-v")
 
-	se.argvCreate = append(argv, taskCfg.Args...)
+	se.argvCreate = argv
 
 	potName := completeName + "_" + cfg.AllocID
 
@@ -140,7 +148,7 @@ func prepareContainer(cfg *drivers.TaskConfig, taskCfg TaskConfig) syexec {
 	argvStats = append(argvStats, "get-rss", "-p", potName, "-J")
 	se.argvStats = argvStats
 
-	return se
+	return se, nil
 }
 
 type nopCloser struct {