Add support for creating directories (#33)

Author: uschi2000

README.md

@@ -31,6 +31,10 @@ jvmOpts:
 # OPTIONAL - Arguments passed to the main method of the main class
 args:
   - arg1
+# OPTIONAL - A list of directories to be created before executing the command. Must be relative to CWD and over [A-Za-z0-9].
+args:
+  - var/data/tmp
+  - var/log
 ```
 
 ```yaml
@@ -47,6 +51,10 @@ executable: "{{CWD}}/service/bin/postgres"
 # OPTIONAL - Arguments passed to the main method of the excutable or main class
 args:
   - arg1
+# OPTIONAL - A list of directories to be created before executing the command. Must be relative to CWD and over [A-Za-z0-9].
+args:
+  - var/data/tmp
+  - var/log
 ```
 
 ```yaml

integration_test/integration_test.go

@@ -15,6 +15,7 @@
 package integration_test
 
 import (
+	"os"
 	"os/exec"
 	"testing"
 
@@ -49,6 +50,21 @@ func TestMainMethodWithoutCustomConfig(t *testing.T) {
 	assert.Regexp(t, `\nmain method\n`, string(output))
 }
 
+func TestCreatesDirs(t *testing.T) {
+	output, err := runMainWithArgs(t, "test_resources/launcher-static-with-dirs.yml", "foo")
+	require.NoError(t, err, "failed: %s", output)
+
+	dir, err := os.Stat("foo")
+	assert.NoError(t, err)
+	assert.True(t, dir.IsDir())
+	require.NoError(t, os.RemoveAll("foo"))
+
+	dir, err = os.Stat("bar/baz")
+	assert.NoError(t, err)
+	assert.True(t, dir.IsDir())
+	require.NoError(t, os.RemoveAll("bar"))
+}
+
 func runMainWithArgs(t *testing.T, staticConfigFile, customConfigFile string) (string, error) {
 	cli, err := products.Bin("go-java-launcher")
 	require.NoError(t, err)

integration_test/test_resources/launcher-static-with-dirs.yml

@@ -0,0 +1,12 @@
+configType: java
+configVersion: 1
+mainClass: Main
+classpath:
+  - ./test_resources/
+jvmOpts:
+  - '-Xmx4M'
+args:
+  - arg1
+dirs:
+  - foo
+  - bar/baz

launcher/main/main.go

@@ -41,12 +41,32 @@ func main() {
 		customConfigFile = os.Args[2]
 	}
 
-	cmd, err := launchlib.CompileCmdFromConfigFiles(staticConfigFile, customConfigFile)
+	// Read configuration
+	staticConfig, err := launchlib.GetStaticConfigFromFile(staticConfigFile)
+	if err != nil {
+		fmt.Println("Failed to read static config file", err)
+		panic(err)
+	}
+	customConfig, err := launchlib.GetCustomConfigFromFile(customConfigFile)
+	if err != nil {
+		fmt.Println("Failed to read custom config file", err)
+		panic(err)
+	}
+
+	// Create configured directories
+	if err := launchlib.MkDirs(staticConfig.Dirs); err != nil {
+		fmt.Println("Failed to create directories", err)
+		panic(err)
+	}
+
+	// Compile command
+	cmd, err := launchlib.CompileCmdFromConfig(&staticConfig, &customConfig)
 	if err != nil {
 		fmt.Println("Failed to assemble executable metadata", cmd, err)
 		panic(err)
 	}
 
+	// Execute command
 	execErr := syscall.Exec(cmd.Path, cmd.Args, cmd.Env)
 	if execErr != nil {
 		if os.IsNotExist(execErr) {

launchlib/config.go

@@ -41,6 +41,7 @@ type StaticLauncherConfig struct {
 	Env            map[string]string `yaml:"env"`
 	Executable     string            `yaml:"executable,omitempty"`
 	Args           []string          `yaml:"args"`
+	Dirs           []string          `yaml:"dirs"`
 }
 
 type CustomLauncherConfig struct {

launchlib/launcher.go

@@ -91,6 +91,21 @@ func CompileCmdFromConfig(staticConfig *StaticLauncherConfig, customConfig *Cust
 	return createCmd(executable, args, env)
 }
 
+func MkDirs(dirs []string) error {
+	isDirMatcher := regexp.MustCompile(`^[A-Za-z0-9]+(/[A-Za-z0-9]+)*$`).MatchString
+	for _, dir := range dirs {
+		if !isDirMatcher(dir) {
+			return fmt.Errorf("Cannot create directory with non [A-Za-z0-9] characters: %s", dir)
+		}
+
+		fmt.Printf("Creating directory: %s\n", dir)
+		if err := os.MkdirAll(dir, 0700); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 // Returns true iff the given path is safe to be passed to exec(): must not contain funky characters and be a valid file.
 func verifyPathIsSafeForExec(execPath string) (string, error) {
 	if unsafe, err := regexp.MatchString(ExecPathBlackListRegex, execPath); err != nil {

launchlib/launcher_test.go

@@ -112,3 +112,23 @@ func TestKeysAreNotExpanded(t *testing.T) {
 		t.Errorf("Expected %%CWD%% to exist in map and not be expanded, but it didn't")
 	}
 }
+
+func TestMkdirChecksDirectorySyntax(t *testing.T) {
+	err := MkDirs([]string{"abc/def1"})
+	assert.NoError(t, err)
+
+	err = MkDirs([]string{"abc"})
+	assert.NoError(t, err)
+
+	require.NoError(t, os.RemoveAll("abc"))
+
+	badCases := []string{
+		"^&*",
+		"abc//def",
+		"abc/../def",
+	}
+	for _, dir := range badCases {
+		err = MkDirs([]string{dir})
+		assert.EqualError(t, err, "Cannot create directory with non [A-Za-z0-9] characters: "+dir)
+	}
+}