Makes OpenSSH control sockets path directory configurable

> closes #48

Author: HorlogeSkynet

README.md

@@ -67,6 +67,10 @@ Open your command palette and type in `SSHubl` to select `Connect to server`. On
 	// Custom path to `umount` program (`fusermount` on Linux)
 	// /!\ This setting requires plugin reload (or Sublime restart)
 	"umount_path": null,
+	// Custom path to OpenSSH control sockets directory
+	// /!\ This setting requires plugin reload (or Sublime restart)
+	// If you hit "path [...] too long for Unix domain socket" error, you may set this to e.g. "/tmp/sshubl"
+	"sockets_path": null,
 	// Custom options to pass to OpenSSH **master** (e.g. useful for bastion traversal)
 	"ssh_options": {
 		//"ConnectTimeout": 30,

SSHubl.sublime-settings

@@ -3,6 +3,7 @@
 	"ssh_path": null,
 	"sshfs_path": null,
 	"umount_path": null,
+	"sockets_path": null,
 	"ssh_options": {},
 	"ssh_server_alive_interval": 15,
 	"ssh_login_timeout": 10,

sshubl/paths.py

@@ -2,10 +2,24 @@
 
 import sublime
 
+
+def _settings():
+    return sublime.load_settings("SSHubl.sublime-settings")
+
+
 cache_path = Path(sublime.cache_path()) / "SSHubl"
 cache_path.mkdir(parents=True, exist_ok=True)
 
-sockets_path = cache_path / "sockets"
+# OpenSSH binds a temporary UNIX domain socket which is 17 bytes longer than the provided path [1].
+# Depending on platform and username, such a path may not fit in kernel pre-allocated space [2]. So
+# let's allow users to define their own SSHubl control sockets directory location.
+# [1] : <https://github.com/openssh/openssh-portable/blob/5e4bfe6/mux.c#L1285-L1303>
+# [2] : <https://unix.stackexchange.com/a/367012>
+_sockets_path = _settings().get("sockets_path")
+if _sockets_path is not None:
+    sockets_path = Path(_sockets_path)
+else:
+    sockets_path = cache_path / "sockets"
 sockets_path.mkdir(mode=0o750, exist_ok=True)
 
 mounts_path = cache_path / "mounts"