define server command #48 and improved error handling

abcd/backends/atoms_pymongo.py

@@ -11,11 +11,13 @@
 from ase import Atoms
 from ase.io import iread
 
+import abcd.errors
 from abcd.model import AbstractModel
 from abcd.database import AbstractABCD
 from abcd.queryset import AbstractQuerySet
 from abcd.parsers import extras
 
+import pymongo.errors
 from pymongo import MongoClient
 from bson import ObjectId
 
@@ -155,6 +157,16 @@ def __init__(self, host='localhost', port=27017,
             host=host, port=port, username=username, password=password,
             authSource=authSource)
 
+        try:
+            info = self.client.server_info()  # Forces a call.
+            logger.info('DB info: {}'.format(info))
+
+        except pymongo.errors.OperationFailure:
+            raise abcd.errors.AuthenticationError()
+
+        except pymongo.errors.ServerSelectionTimeoutError:
+            raise abcd.errors.TimeoutError()
+
         self.db = self.client[db_name]
         self.collection = self.db[collection_name]
 

abcd/errors.py

@@ -12,3 +12,7 @@ class AuthenticationError(ABCDError):
 
 class PropertyNotImplementedError(NotImplementedError):
     """Raised if a calculator does not implement the requested property."""
+
+
+class TimeoutError(ABCDError):
+    pass

abcd/frontends/commandline/commands.py

@@ -12,28 +12,19 @@
 def login(*, config, name, url, **kwargs):
     logger.info('login args: \nconfig:{}, name:{}, url:{}, kwargs:{}'.format(config, name, url, kwargs))
     from abcd import ABCD
-    from abcd.errors import URLError, AuthenticationError
 
-    try:
-        db = ABCD.from_url(url=url)
-        info = db.info()
+    db = ABCD.from_url(url=url)
+    info = db.info()
 
-        config['url'] = url
-        config.save()
+    config['url'] = url
+    config.save()
 
-        print('Successfully connected to the database!')
-        print(" type:       {type}\n"
-              " hostname:   {host}\n"
-              " port:       {port}\n"
-              " database:   {db}\n"
-              " # of confs: {number of confs}".format(**info))
-
-    except URLError:
-        print('Wrong connection: Please check the parameters of th url!')
-        exit(1)
-    except AuthenticationError:
-        print('Authentication failed!')
-        exit(1)
+    print('Successfully connected to the database!')
+    print(" type:       {type}\n"
+          " hostname:   {host}\n"
+          " port:       {port}\n"
+          " database:   {db}\n"
+          " # of confs: {number of confs}".format(**info))
 
 
 @init_config
@@ -254,6 +245,12 @@ def execute(*, db, query, yes, python_code, **kwargs):
     db.exec(python_code, query)
 
 
+@check_readonly
+def server(*, abcd_url, url, api_only, **kwargs):
+    logger.info("SERVER -  abcd: {}, url: {}, api_only:{}".format(abcd_url, url, api_only))
+    exit(0)
+
+
 class Formater(object):
     partialBlocks = ["▏", "▎", "▍", "▌", "▋", "▊", "▉", "█"]  # char=pb
 

abcd/frontends/commandline/parser.py

@@ -1,6 +1,7 @@
 import logging
-from argparse import ArgumentParser, REMAINDER
+from argparse import ArgumentParser
 from abcd.frontends.commandline import commands
+from abcd.errors import URLError, AuthenticationError, TimeoutError
 
 logger = logging.getLogger(__name__)
 
@@ -85,6 +86,12 @@
 exec_parser.add_argument('-y', '--yes', action='store_true', help='Do the actual execution.')
 exec_parser.add_argument('python_code', help='Selecting properties for detailed description')
 
+server = subparsers.add_parser('server', help='Running custom python code')
+server.set_defaults(callback_func=commands.server)
+server.add_argument('abcd_url', help='Url for abcd database.')
+server.add_argument('--api-only', action='store_true', help='Running only the API.')
+server.add_argument('-u', '--url', help='Url to run the server.', default='http://localhost:27017')
+
 
 def main(args=None):
     kwargs = parser.parse_args(args).__dict__
@@ -102,9 +109,19 @@ def main(args=None):
         print(parser.format_help())
         return
 
-    # return namespace.callback_func(namespace)
-    callback_func = kwargs.pop('callback_func')
-    return callback_func(**kwargs)
+    try:
+        callback_func = kwargs.pop('callback_func')
+        callback_func(**kwargs)
+
+    except URLError:
+        print('Wrong connection: Please check the parameters of the url!')
+        exit(1)
+    except AuthenticationError:
+        print('Authentication failed: Please check the parameters of the connection!')
+        exit(1)
+    except TimeoutError:
+        print("Timeout: Please check the parameters of the connection!")
+        exit(1)
 
 
 if __name__ == '__main__':