rebase: vendor dependencies for Vault API

Uses github.com/libopenstorage/secrets to communicate with Vault. This
removes the need for maintaining our own limited Vault APIs.

By adding the new dependency, several other packages got updated in the
process. Unused indirect dependencies have been removed from go.mod.

Signed-off-by: Niels de Vos <ndevos@redhat.com>

vendor/github.com/mitchellh/go-homedir/homedir.go

@@ -0,0 +1,167 @@
+package homedir
+
+import (
+	"bytes"
+	"errors"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+// DisableCache will disable caching of the home directory. Caching is enabled
+// by default.
+var DisableCache bool
+
+var homedirCache string
+var cacheLock sync.RWMutex
+
+// Dir returns the home directory for the executing user.
+//
+// This uses an OS-specific method for discovering the home directory.
+// An error is returned if a home directory cannot be detected.
+func Dir() (string, error) {
+	if !DisableCache {
+		cacheLock.RLock()
+		cached := homedirCache
+		cacheLock.RUnlock()
+		if cached != "" {
+			return cached, nil
+		}
+	}
+
+	cacheLock.Lock()
+	defer cacheLock.Unlock()
+
+	var result string
+	var err error
+	if runtime.GOOS == "windows" {
+		result, err = dirWindows()
+	} else {
+		// Unix-like system, so just assume Unix
+		result, err = dirUnix()
+	}
+
+	if err != nil {
+		return "", err
+	}
+	homedirCache = result
+	return result, nil
+}
+
+// Expand expands the path to include the home directory if the path
+// is prefixed with `~`. If it isn't prefixed with `~`, the path is
+// returned as-is.
+func Expand(path string) (string, error) {
+	if len(path) == 0 {
+		return path, nil
+	}
+
+	if path[0] != '~' {
+		return path, nil
+	}
+
+	if len(path) > 1 && path[1] != '/' && path[1] != '\\' {
+		return "", errors.New("cannot expand user-specific home dir")
+	}
+
+	dir, err := Dir()
+	if err != nil {
+		return "", err
+	}
+
+	return filepath.Join(dir, path[1:]), nil
+}
+
+// Reset clears the cache, forcing the next call to Dir to re-detect
+// the home directory. This generally never has to be called, but can be
+// useful in tests if you're modifying the home directory via the HOME
+// env var or something.
+func Reset() {
+	cacheLock.Lock()
+	defer cacheLock.Unlock()
+	homedirCache = ""
+}
+
+func dirUnix() (string, error) {
+	homeEnv := "HOME"
+	if runtime.GOOS == "plan9" {
+		// On plan9, env vars are lowercase.
+		homeEnv = "home"
+	}
+
+	// First prefer the HOME environmental variable
+	if home := os.Getenv(homeEnv); home != "" {
+		return home, nil
+	}
+
+	var stdout bytes.Buffer
+
+	// If that fails, try OS specific commands
+	if runtime.GOOS == "darwin" {
+		cmd := exec.Command("sh", "-c", `dscl -q . -read /Users/"$(whoami)" NFSHomeDirectory | sed 's/^[^ ]*: //'`)
+		cmd.Stdout = &stdout
+		if err := cmd.Run(); err == nil {
+			result := strings.TrimSpace(stdout.String())
+			if result != "" {
+				return result, nil
+			}
+		}
+	} else {
+		cmd := exec.Command("getent", "passwd", strconv.Itoa(os.Getuid()))
+		cmd.Stdout = &stdout
+		if err := cmd.Run(); err != nil {
+			// If the error is ErrNotFound, we ignore it. Otherwise, return it.
+			if err != exec.ErrNotFound {
+				return "", err
+			}
+		} else {
+			if passwd := strings.TrimSpace(stdout.String()); passwd != "" {
+				// username:password:uid:gid:gecos:home:shell
+				passwdParts := strings.SplitN(passwd, ":", 7)
+				if len(passwdParts) > 5 {
+					return passwdParts[5], nil
+				}
+			}
+		}
+	}
+
+	// If all else fails, try the shell
+	stdout.Reset()
+	cmd := exec.Command("sh", "-c", "cd && pwd")
+	cmd.Stdout = &stdout
+	if err := cmd.Run(); err != nil {
+		return "", err
+	}
+
+	result := strings.TrimSpace(stdout.String())
+	if result == "" {
+		return "", errors.New("blank output when reading home directory")
+	}
+
+	return result, nil
+}
+
+func dirWindows() (string, error) {
+	// First prefer the HOME environmental variable
+	if home := os.Getenv("HOME"); home != "" {
+		return home, nil
+	}
+
+	// Prefer standard environment variable USERPROFILE
+	if home := os.Getenv("USERPROFILE"); home != "" {
+		return home, nil
+	}
+
+	drive := os.Getenv("HOMEDRIVE")
+	path := os.Getenv("HOMEPATH")
+	home := drive + path
+	if drive == "" || path == "" {
+		return "", errors.New("HOMEDRIVE, HOMEPATH, or USERPROFILE are blank")
+	}
+
+	return home, nil
+}