Remove go-homedir dependency

This is overcomplicated for a very simple requirement. It can call
`exec`, it has a cache protected by a mutex because it is so complex.
Just use the per platform environment variables which will always be
set, if the user has a weird environment they can specify full paths.

Signed-off-by: Justin Cormack <[email protected]>

cmd/notary/main.go

@@ -7,7 +7,6 @@ import (
 	"path/filepath"
 	"strings"
 
-	homedir "github.com/mitchellh/go-homedir"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
@@ -75,9 +74,9 @@ func (n *notaryCommander) parseConfig() (*viper.Viper, error) {
 	n.setVerbosityLevel()
 
 	// Get home directory for current user
-	homeDir, err := homedir.Dir()
-	if err != nil {
-		logrus.Warnf("cannot get current user home directory: %v", err)
+	homeDir := os.Getenv(homeEnv)
+	if homeDir == "" {
+		logrus.Warn("cannot get current user home directory: environment variable not set")
 		pwd, _ := os.Getwd()
 		logrus.Warnf("notary will use %s to store configuration and keys", filepath.Join(pwd, configDir))
 	}
@@ -129,11 +128,9 @@ func (n *notaryCommander) parseConfig() (*viper.Viper, error) {
 	}
 
 	// Expands all the possible ~/ that have been given, either through -d or config
-	// If there is no error, use it, if not, just attempt to use whatever the user gave us
-	expandedTrustDir, err := homedir.Expand(config.GetString("trust_dir"))
-	if err == nil {
-		config.Set("trust_dir", expandedTrustDir)
-	}
+	// Otherwise just attempt to use whatever the user gave us
+	expandedTrustDir := homeExpand(homeDir, config.GetString("trust_dir"))
+	config.Set("trust_dir", expandedTrustDir)
 	logrus.Debugf("Using the following trust directory: %s", config.GetString("trust_dir"))
 
 	return config, nil

cmd/notary/util.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"path/filepath"
 )
 
 const (
@@ -52,3 +53,12 @@ func feedback(t *tufCommander, payload []byte) error {
 	os.Stdout.Write(payload)
 	return nil
 }
+
+// homeExpand will expand an initial ~ to the user home directory. This is supported for
+// config files where the shell will not have expanded paths.
+func homeExpand(homeDir, path string) string {
+	if path == "" || path[1] != '~' || (len(path) > 1 && path[1] != os.PathSeparator) {
+		return path
+	}
+	return filepath.Join(homeDir, path[1:])
+}

cmd/notary/util_unix.go

@@ -0,0 +1,5 @@
+// +build !windows
+
+package main
+
+const homeEnv = "HOME"

cmd/notary/util_windows.go

@@ -0,0 +1,3 @@
+package main
+
+const homeEnv = "USERPROFILE"

vendor.conf

@@ -16,7 +16,6 @@ github.com/jinzhu/inflection        1c35d901db3da928c72a72d8458480cc9ade058f
 github.com/lib/pq                   0dad96c0b94f8dee039aa40467f767467392a0af
 github.com/mattn/go-sqlite3         6c771bb9887719704b210e87e934f08be014bdb1   # v1.6.0
 github.com/miekg/pkcs11             5f6e0d0dad6f472df908c8e968a98ef00c9224bb
-github.com/mitchellh/go-homedir     df55a15e5ce646808815381b3db47a8c66ea62f4
 github.com/prometheus/client_golang 449ccefff16c8e2b7229f6be1921ba22f62461fe
 github.com/prometheus/client_model  fa8ad6fec33561be4280a8f0514318c79d7f6cb6   # model-0.0.2-12-gfa8ad6f
 github.com/prometheus/procfs	    b1afdc266f54247f5dc725544f5d351a8661f502