TUN-4063: Cleanup dependencies between packages.

- Move packages the provide generic functionality (such as config) from `cmd` subtree to top level.
- Remove all dependencies on `cmd` subtree from top level packages.
- Consolidate all code dealing with token generation and transfer to a single cohesive package.

token/path.go

@@ -0,0 +1,46 @@
+package token
+
+import (
+	"fmt"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/mitchellh/go-homedir"
+
+	"github.com/cloudflare/cloudflared/config"
+)
+
+// GenerateAppTokenFilePathFromURL will return a filepath for given Access org token
+func GenerateAppTokenFilePathFromURL(url *url.URL, suffix string) (string, error) {
+	configPath, err := getConfigPath()
+	if err != nil {
+		return "", err
+	}
+	name := strings.Replace(fmt.Sprintf("%s%s-%s", url.Hostname(), url.EscapedPath(), suffix), "/", "-", -1)
+	return filepath.Join(configPath, name), nil
+}
+
+// generateOrgTokenFilePathFromURL will return a filepath for given Access application token
+func generateOrgTokenFilePathFromURL(authDomain string) (string, error) {
+	configPath, err := getConfigPath()
+	if err != nil {
+		return "", err
+	}
+	name := strings.Replace(fmt.Sprintf("%s-org-token", authDomain), "/", "-", -1)
+	return filepath.Join(configPath, name), nil
+}
+
+func getConfigPath() (string, error) {
+	configPath, err := homedir.Expand(config.DefaultConfigSearchDirectories()[0])
+	if err != nil {
+		return "", err
+	}
+	ok, err := config.FileExists(configPath)
+	if !ok && err == nil {
+		// create config directory if doesn't already exist
+		err = os.Mkdir(configPath, 0700)
+	}
+	return configPath, err
+}