Add ALLOW_ROOT option (#268)

* Add ALLOW_ROOT option

* Document ALLOW_ROOT option

* Update controller.py

* Update ENVIRONMENT.rst

docs/ENVIRONMENT.rst

@@ -64,6 +64,10 @@ Miscellaneous
 
 These environment variables are optional:
 
+* **ALLOW_ROOT**
+
+  Set this environment variable to anything non-empty to allow running ElectrumX as root.
+
 * **NET**
 
   Must be a *NET* from one of the **Coin** classes in `lib/coins.py`_.

server/controller.py

@@ -51,9 +51,12 @@ class Controller(util.LoggedClass):
         if sys.version_info < (3, 5, 3):
             raise RuntimeError('Python >= 3.5.3 is required to run ElectrumX')
 
-        if os.geteuid() == 0:
-            raise RuntimeError('DO NOT RUN AS ROOT! Create an unprivileged '
-                               'user account and use that')
+        if os.geteuid() == 0 and not env.allow_root:
+            raise RuntimeError('RUNNING AS ROOT IS STRONGLY DISCOURAGED!\n'
+                               'You shoud create an unprivileged user account '
+                               'and use that.\n'
+                               'To continue as root anyway, restart with '
+                               'environment variable ALLOW_ROOT non-empty')
 
         # Set the event loop policy before doing anything asyncio
         self.logger.info('event loop policy: {}'.format(env.loop_policy))

server/env.py

@@ -29,6 +29,7 @@ class Env(lib_util.LoggedClass):
     def __init__(self):
         super().__init__()
         self.obsolete(['UTXO_MB', 'HIST_MB', 'NETWORK'])
+        self.allow_root = self.boolean('ALLOW_ROOT', False)
         self.db_dir = self.required('DB_DIRECTORY')
         self.daemon_url = self.required('DAEMON_URL')
         coin_name = self.required('COIN').strip()