Merge pull request #1637 from vrothberg/runlabel-execute-any-command

runlabel: run any command

3 files changed, 122 insertions, 11 deletions

diff --git a/cmd/podman/runlabel.go b/cmd/podman/runlabel.go
index aa7411a5f..e1dee1fb2 100644
--- a/cmd/podman/runlabel.go
+++ b/cmd/podman/runlabel.go
@@ -196,7 +196,10 @@ func runlabelCmd(c *cli.Context) error {
 		runLabel = fmt.Sprintf("%s %s", runLabel, strings.Join(args[2:], " "))
 	}
 
-	cmd := shared.GenerateCommand(runLabel, imageName, c.String("name"))
+	cmd, err := shared.GenerateCommand(runLabel, imageName, c.String("name"))
+	if err != nil {
+		return errors.Wrapf(err, "unable to generate command")
+	}
 	env := shared.GenerateRunEnvironment(c.String("name"), imageName, opts)
 	env = append(env, "PODMAN_RUNLABEL_NESTED=1")
 
diff --git a/cmd/podman/shared/funcs.go b/cmd/podman/shared/funcs.go
index 485944f29..a92e0d547 100644
--- a/cmd/podman/shared/funcs.go
+++ b/cmd/podman/shared/funcs.go
@@ -3,11 +3,39 @@ package shared
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 	"strings"
 )
 
+func substituteCommand(cmd string) (string, error) {
+	// If cmd is an absolute or relative path, check if the file exists.
+	// Throw an error if it doesn't exist.
+	if strings.Contains(cmd, "/") || strings.HasPrefix(cmd, ".") {
+		res, err := filepath.Abs(cmd)
+		if err != nil {
+			return "", err
+		}
+		if _, err := os.Stat(res); !os.IsNotExist(err) {
+			return res, nil
+		} else if err != nil {
+			return "", err
+		}
+	}
+
+	// Replace cmd with "/proc/self/exe" if "podman" or "docker" is being
+	// used.  Otherwise, leave the command unchanged.
+	switch cmd {
+	case "podman":
+		fallthrough
+	case "docker":
+		return "/proc/self/exe", nil
+	default:
+		return cmd, nil
+	}
+}
+
 // GenerateCommand takes a label (string) and converts it to an executable command
-func GenerateCommand(command, imageName, name string) []string {
+func GenerateCommand(command, imageName, name string) ([]string, error) {
 	var (
 		newCommand []string
 	)
@@ -15,8 +43,13 @@ func GenerateCommand(command, imageName, name string) []string {
 		name = imageName
 	}
 	cmd := strings.Split(command, " ")
-	// Replace the first element of cmd with "/proc/self/exe"
-	newCommand = append(newCommand, "/proc/self/exe")
+
+	prog, err := substituteCommand(cmd[0])
+	if err != nil {
+		return nil, err
+	}
+	newCommand = append(newCommand, prog)
+
 	for _, arg := range cmd[1:] {
 		var newArg string
 		switch arg {
@@ -37,7 +70,7 @@ func GenerateCommand(command, imageName, name string) []string {
 		}
 		newCommand = append(newCommand, newArg)
 	}
-	return newCommand
+	return newCommand, nil
 }
 
 // GenerateRunEnvironment merges the current environment variables with optional
diff --git a/cmd/podman/shared/funcs_test.go b/cmd/podman/shared/funcs_test.go
index 612be480b..596df84e8 100644
--- a/cmd/podman/shared/funcs_test.go
+++ b/cmd/podman/shared/funcs_test.go
@@ -1,6 +1,10 @@
 package shared
 
 import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -16,35 +20,106 @@ var (
 func TestGenerateCommand(t *testing.T) {
 	inputCommand := "docker run -it --name NAME -e NAME=NAME -e IMAGE=IMAGE IMAGE echo install"
 	correctCommand := "/proc/self/exe run -it --name bar -e NAME=bar -e IMAGE=foo foo echo install"
-	newCommand := GenerateCommand(inputCommand, "foo", "bar")
+	newCommand, err := GenerateCommand(inputCommand, "foo", "bar")
+	assert.Nil(t, err)
 	assert.Equal(t, correctCommand, strings.Join(newCommand, " "))
 }
 
+func TestGenerateCommandCheckSubstitution(t *testing.T) {
+	type subsTest struct {
+		input      string
+		expected   string
+		shouldFail bool
+	}
+
+	absTmpFile, err := ioutil.TempFile("", "podmanRunlabelTestAbsolutePath")
+	assert.Nil(t, err, "error creating tempfile")
+	defer os.Remove(absTmpFile.Name())
+
+	relTmpFile, err := ioutil.TempFile("./", "podmanRunlabelTestRelativePath")
+	assert.Nil(t, err, "error creating tempfile")
+	defer os.Remove(relTmpFile.Name())
+	relTmpCmd, err := filepath.Abs(relTmpFile.Name())
+	assert.Nil(t, err, "error getting absolute path for relative tmpfile")
+
+	// this has a (low) potential of race conditions but no other way
+	removedTmpFile, err := ioutil.TempFile("", "podmanRunlabelTestRemove")
+	assert.Nil(t, err, "error creating tempfile")
+	os.Remove(removedTmpFile.Name())
+
+	absTmpCmd := fmt.Sprintf("%s --flag1 --flag2 --args=foo", absTmpFile.Name())
+	tests := []subsTest{
+		{
+			input:      "docker run -it alpine:latest",
+			expected:   "/proc/self/exe run -it alpine:latest",
+			shouldFail: false,
+		},
+		{
+			input:      "podman run -it alpine:latest",
+			expected:   "/proc/self/exe run -it alpine:latest",
+			shouldFail: false,
+		},
+		{
+			input:      absTmpCmd,
+			expected:   absTmpCmd,
+			shouldFail: false,
+		},
+		{
+			input:      "./" + relTmpFile.Name(),
+			expected:   relTmpCmd,
+			shouldFail: false,
+		},
+		{
+			input:      "ls -la",
+			expected:   "ls -la",
+			shouldFail: false,
+		},
+		{
+			input:      removedTmpFile.Name(),
+			expected:   "",
+			shouldFail: true,
+		},
+	}
+
+	for _, test := range tests {
+		newCommand, err := GenerateCommand(test.input, "foo", "bar")
+		if test.shouldFail {
+			assert.NotNil(t, err)
+		} else {
+			assert.Nil(t, err)
+		}
+		assert.Equal(t, test.expected, strings.Join(newCommand, " "))
+	}
+}
+
 func TestGenerateCommandPath(t *testing.T) {
-	inputCommand := "/usr/bin/docker run -it --name NAME -e NAME=NAME -e IMAGE=IMAGE IMAGE echo install"
+	inputCommand := "docker run -it --name NAME -e NAME=NAME -e IMAGE=IMAGE IMAGE echo install"
 	correctCommand := "/proc/self/exe run -it --name bar -e NAME=bar -e IMAGE=foo foo echo install"
-	newCommand := GenerateCommand(inputCommand, "foo", "bar")
+	newCommand, _ := GenerateCommand(inputCommand, "foo", "bar")
 	assert.Equal(t, correctCommand, strings.Join(newCommand, " "))
 }
 
 func TestGenerateCommandNoSetName(t *testing.T) {
 	inputCommand := "docker run -it --name NAME -e NAME=NAME -e IMAGE=IMAGE IMAGE echo install"
 	correctCommand := "/proc/self/exe run -it --name foo -e NAME=foo -e IMAGE=foo foo echo install"
-	newCommand := GenerateCommand(inputCommand, "foo", "")
+	newCommand, err := GenerateCommand(inputCommand, "foo", "")
+	assert.Nil(t, err)
 	assert.Equal(t, correctCommand, strings.Join(newCommand, " "))
 }
 
 func TestGenerateCommandNoName(t *testing.T) {
 	inputCommand := "docker run -it  -e IMAGE=IMAGE IMAGE echo install"
 	correctCommand := "/proc/self/exe run -it  -e IMAGE=foo foo echo install"
-	newCommand := GenerateCommand(inputCommand, "foo", "")
+	newCommand, err := GenerateCommand(inputCommand, "foo", "")
+	assert.Nil(t, err)
 	assert.Equal(t, correctCommand, strings.Join(newCommand, " "))
 }
 
 func TestGenerateCommandAlreadyPodman(t *testing.T) {
 	inputCommand := "podman run -it --name NAME -e NAME=NAME -e IMAGE=IMAGE IMAGE echo install"
 	correctCommand := "/proc/self/exe run -it --name bar -e NAME=bar -e IMAGE=foo foo echo install"
-	newCommand := GenerateCommand(inputCommand, "foo", "bar")
+	newCommand, err := GenerateCommand(inputCommand, "foo", "bar")
+	assert.Nil(t, err)
 	assert.Equal(t, correctCommand, strings.Join(newCommand, " "))
 }