Dispatcher creates parent directory of UNIX socket files

go/godispatcher/BUILD.bazel

@@ -13,6 +13,7 @@ go_library(
         "//go/lib/env:go_default_library",
         "//go/lib/fatal:go_default_library",
         "//go/lib/log:go_default_library",
+        "//go/lib/util:go_default_library",
         "@com_github_burntsushi_toml//:go_default_library",
     ],
 )

go/godispatcher/main.go

@@ -30,6 +30,7 @@ import (
 	"github.com/scionproto/scion/go/lib/env"
 	"github.com/scionproto/scion/go/lib/fatal"
 	"github.com/scionproto/scion/go/lib/log"
+	"github.com/scionproto/scion/go/lib/util"
 )
 
 var (
@@ -60,6 +61,11 @@ func realMain() int {
 		return 1
 	}
 
+	if err := util.CreateParentDirs(cfg.Dispatcher.ApplicationSocket); err != nil {
+		log.Crit("Unable to create directory tree for socket", "err", err)
+		return 1
+	}
+
 	go func() {
 		defer log.LogPanicAndExit()
 		err := RunDispatcher(

go/lib/util/BUILD.bazel

@@ -10,6 +10,7 @@ go_library(
         "duration.go",
         "duration_wrap.go",
         "file.go",
+        "fs.go",
         "map.go",
         "padding.go",
         "raw.go",

go/lib/util/fs.go

@@ -0,0 +1,31 @@
+// Copyright 2019 ETH Zurich
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package util
+
+import (
+	"os"
+	"path/filepath"
+)
+
+// CreateParentDir creates the necessary parent directories for file.
+func CreateParentDirs(file string) error {
+	dir := filepath.Dir(file)
+	if _, err := os.Stat(dir); os.IsNotExist(err) {
+		if err = os.MkdirAll(dir, 0755); err != nil {
+			return err
+		}
+	}
+	return nil
+}

go/sciond/internal/config/config.go

@@ -17,8 +17,6 @@ package config
 
 import (
 	"io"
-	"os"
-	"path/filepath"
 	"time"
 
 	"github.com/scionproto/scion/go/lib/common"
@@ -147,18 +145,11 @@ func (cfg *SDConfig) ConfigName() string {
 }
 
 func (cfg *SDConfig) CreateSocketDirs() error {
-	reliableDir := filepath.Dir(cfg.Reliable)
-	if _, err := os.Stat(reliableDir); os.IsNotExist(err) {
-		if err = os.MkdirAll(reliableDir, 0755); err != nil {
-			return common.NewBasicError("Cannot create reliable socket dir", err, "dir",
-				reliableDir)
-		}
+	if err := util.CreateParentDirs(cfg.Reliable); err != nil {
+		return common.NewBasicError("Cannot create reliable socket dir", err)
 	}
-	unixDir := filepath.Dir(cfg.Unix)
-	if _, err := os.Stat(unixDir); os.IsNotExist(err) {
-		if err = os.MkdirAll(unixDir, 0755); err != nil {
-			return common.NewBasicError("Cannot create unix socket dir", err, "dir", unixDir)
-		}
+	if err := util.CreateParentDirs(cfg.Unix); err != nil {
+		return common.NewBasicError("Cannot create unix socket dir", err)
 	}
 	return nil
 }