From 41d6635026b048f68256a4f7c6ee669ef0d616d8 Mon Sep 17 00:00:00 2001
From: Mahmood Ali <mahmood@notnoop.com>
Date: Thu, 3 Jan 2019 12:36:22 -0500
Subject: [PATCH] drivers/exec: run as `nobody` by default

libcontainer based drivers (e.g. exec, java) should default to running
processes as `nobody` [1]; but libcontainer treats empty user as `root`
in our case (either because of default or due to `root` being current
user).

[1] https://github.com/hashicorp/nomad/blob/94c28a4c6cc45f1b377d50a6bff2017b46c43d18/website/source/docs/job-specification/task.html.md#task-parameters
---
 drivers/exec/driver.go | 7 ++++++-
 drivers/java/driver.go | 7 ++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/exec/driver.go b/drivers/exec/driver.go
index 50ba7d059..4bbd337be 100644
--- a/drivers/exec/driver.go
+++ b/drivers/exec/driver.go
@@ -297,11 +297,16 @@ func (d *Driver) StartTask(cfg *drivers.TaskConfig) (*drivers.TaskHandle, *cstru
 		return nil, nil, fmt.Errorf("failed to create executor: %v", err)
 	}
 
+	user := cfg.User
+	if user == "" {
+		user = "nobody"
+	}
+
 	execCmd := &executor.ExecCommand{
 		Cmd:            driverConfig.Command,
 		Args:           driverConfig.Args,
 		Env:            cfg.EnvList(),
-		User:           cfg.User,
+		User:           user,
 		ResourceLimits: true,
 		Resources:      cfg.Resources,
 		TaskDir:        cfg.TaskDir().Dir,
diff --git a/drivers/java/driver.go b/drivers/java/driver.go
index b96377da7..1b561697a 100644
--- a/drivers/java/driver.go
+++ b/drivers/java/driver.go
@@ -328,11 +328,16 @@ func (d *Driver) StartTask(cfg *drivers.TaskConfig) (*drivers.TaskHandle, *cstru
 		return nil, nil, fmt.Errorf("failed to create executor: %v", err)
 	}
 
+	user := cfg.User
+	if user == "" {
+		user = "nobody"
+	}
+
 	execCmd := &executor.ExecCommand{
 		Cmd:            absPath,
 		Args:           args,
 		Env:            cfg.EnvList(),
-		User:           cfg.User,
+		User:           user,
 		ResourceLimits: true,
 		Resources:      cfg.Resources,
 		TaskDir:        cfg.TaskDir().Dir,