From d1faa82a0a8e0d0c0cf3bc47767bfbe3e5e4736f Mon Sep 17 00:00:00 2001
From: Rajasekaran <rajasec79@gmail.com>
Date: Mon, 7 Mar 2016 23:06:14 +0530
Subject: [PATCH] Adding spec validation for exec and start

Signed-off-by: Rajasekaran <rajasec79@gmail.com>

Fixed review comments

Signed-off-by: rajasec <rajasec79@gmail.com>

Rebased with latest spec version

Signed-off-by: rajasec <rajasec79@gmail.com>
---
 exec.go  |  2 +-
 spec.go  | 14 +-------------
 utils.go | 22 ++++++++++++++++++++++
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/exec.go b/exec.go
index 0f7fe8819..2d70d7613 100644
--- a/exec.go
+++ b/exec.go
@@ -118,7 +118,7 @@ func getProcess(context *cli.Context, bundle string) (*specs.Process, error) {
 		if err := json.NewDecoder(f).Decode(&p); err != nil {
 			return nil, err
 		}
-		return &p, nil
+		return &p, validateProcessSpec(&p)
 	}
 	// process via cli flags
 	if err := os.Chdir(bundle); err != nil {
diff --git a/spec.go b/spec.go
index d5d66fcc9..87bbff886 100644
--- a/spec.go
+++ b/spec.go
@@ -197,18 +197,6 @@ var mountPropagationMapping = map[string]int{
 	"":         syscall.MS_PRIVATE | syscall.MS_REC,
 }
 
-// validateSpec validates the fields in the spec
-// TODO: Add validation for other fields where applicable
-func validateSpec(spec *specs.Spec) error {
-	if spec.Process.Cwd == "" {
-		return fmt.Errorf("Cwd property must not be empty")
-	}
-	if !filepath.IsAbs(spec.Process.Cwd) {
-		return fmt.Errorf("Cwd must be an absolute path")
-	}
-	return nil
-}
-
 // loadSpec loads the specification from the provided path.
 // If the path is empty then the default path will be "config.json"
 func loadSpec(cPath string) (spec *specs.Spec, err error) {
@@ -224,7 +212,7 @@ func loadSpec(cPath string) (spec *specs.Spec, err error) {
 	if err = json.NewDecoder(cf).Decode(&spec); err != nil {
 		return nil, err
 	}
-	return spec, validateSpec(spec)
+	return spec, validateProcessSpec(&spec.Process)
 }
 
 func createLibcontainerConfig(cgroupName string, spec *specs.Spec) (*configs.Config, error) {
diff --git a/utils.go b/utils.go
index 3b43e8536..24b7df1f4 100644
--- a/utils.go
+++ b/utils.go
@@ -365,3 +365,25 @@ func runProcess(container libcontainer.Container, config *specs.Process, listenF
 	}
 	return handler.forward(process)
 }
+
+func validateProcessSpec(spec ...interface{}) error {
+	for _, arg := range spec {
+		switch a := arg.(type) {
+		case *specs.Process:
+			if a.Cwd == "" {
+				return fmt.Errorf("Cwd property must not be empty")
+			}
+			if !filepath.IsAbs(a.Cwd) {
+				return fmt.Errorf("Cwd must be an absolute path")
+			}
+			if len(a.Args) == 0 {
+				return fmt.Errorf("args must not be empty")
+			}
+		//TODO
+		//Add for remaining spec validation
+		default:
+			return fmt.Errorf("not a valid spec")
+		}
+	}
+	return nil
+}