Add an "assets_dir" option for frpc

This option allows users to specify where they want assets to be loaded
from, like the "assets_dir" option that already exists for frps. This
allows library users to use the admin panel without having to bundle
assets with statik.

client/service.go

@@ -96,7 +96,7 @@ func (svr *Service) Run() error {
 
 	if g.GlbClientCfg.AdminPort != 0 {
 		// Init admin server assets
-		err := assets.Load("")
+		err := assets.Load(g.GlbClientCfg.AssetsDir)
 		if err != nil {
 			return fmt.Errorf("Load assets error: %v", err)
 		}

conf/frpc_full.ini

@@ -29,6 +29,8 @@ admin_addr = 127.0.0.1
 admin_port = 7400
 admin_user = admin
 admin_pwd = admin
+# Admin assets directory. By default, these assets are bundled with frpc.
+# assets_dir = ./static
 
 # connections will be established in advance, default value is zero
 pool_count = 5

go.sum

 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 h1:0CwZNZbxp69SHPdPJAN/hZIm0C4OItdklCFmMRWYpio=
 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5/go.mod h1:wHh0iHkYZB8zMSxRWpUBQtwG5a7fFgvEO+odwuTv2gs=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/fatedier/beego v0.0.0-20171024143340-6c6a4f5bd5eb h1:wCrNShQidLmvVWn/0PikGmpdP0vtQmnvyRg3ZBEhczw=
 github.com/fatedier/beego v0.0.0-20171024143340-6c6a4f5bd5eb/go.mod h1:wx3gB6dbIfBRcucp94PI9Bt3I0F2c/MyNEWuhzpWiwk=
@@ -27,6 +28,7 @@ github.com/pires/go-proxyproto v0.0.0-20190111085350-4d51b51e3bfc h1:lNOt1SMsgHX
 github.com/pires/go-proxyproto v0.0.0-20190111085350-4d51b51e3bfc/go.mod h1:6/gX3+E/IYGa0wMORlSMla999awQFdbaeQCHjSMKIzY=
 github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rakyll/statik v0.1.1 h1:fCLHsIMajHqD5RKigbFXpvX3dN7c80Pm12+NCrI3kvg=
 github.com/rakyll/statik v0.1.1/go.mod h1:OEi9wJV/fMUAGx1eNjq75DKDsJVuEv1U0oYdX6GX8Zs=

models/config/client_common.go

@@ -38,6 +38,7 @@ type ClientCommonConf struct {
 	AdminPort         int                 `json:"admin_port"`
 	AdminUser         string              `json:"admin_user"`
 	AdminPwd          string              `json:"admin_pwd"`
+	AssetsDir         string              `json:"assets_dir"`
 	PoolCount         int                 `json:"pool_count"`
 	TcpMux            bool                `json:"tcp_mux"`
 	User              string              `json:"user"`
@@ -65,6 +66,7 @@ func GetDefaultClientConf() *ClientCommonConf {
 		AdminPort:         0,
 		AdminUser:         "",
 		AdminPwd:          "",
+		AssetsDir:         "",
 		PoolCount:         1,
 		TcpMux:            true,
 		User:              "",
@@ -160,6 +162,10 @@ func UnmarshalClientConfFromIni(defaultCfg *ClientCommonConf, content string) (c
 		cfg.AdminPwd = tmpStr
 	}
 
+	if tmpStr, ok = conf.Get("common", "assets_dir"); ok {
+		cfg.AssetsDir = tmpStr
+	}
+
 	if tmpStr, ok = conf.Get("common", "pool_count"); ok {
 		if v, err = strconv.ParseInt(tmpStr, 10, 64); err == nil {
 			cfg.PoolCount = int(v)