Merge branch 'f-server-side-example' into 'dev'

DOC: Example for server-side scripting.

See merge request bmp-caosdb/caosdb-pylib!2

examples/server_side_script.py

+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# ** header v3.0
+# This file is a part of the CaosDB Project.
+#
+# Copyright (C) 2018 Research Group Biomedical Physics,
+# Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program. If not, see <https://www.gnu.org/licenses/>.
+#
+# ** end header
+#
+"""server_side_script.py.
+
+An example which implements a minimal server-side script.
+
+1) This script expects to find a *.txt file in the .upload_files dir which is
+printed to stdout.
+
+2) It executes a "Count stars" query and prints the result to stdout.
+
+3) It will return with code 0 if everything is ok, or with any code that is
+specified with the commandline option --exit
+"""
+
+import sys
+from os import listdir
+from caosdb import configure_connection, execute_query
+
+
+# parse --auth-token option and configure connection
+CODE = 0
+QUERY = "COUNT stars"
+for arg in sys.argv:
+    if arg.startswith("--auth-token="):
+        auth_token = arg[13:]
+        configure_connection(auth_token=auth_token)
+    if arg.startswith("--exit="):
+        CODE = int(arg[7:])
+    if arg.startswith("--query="):
+        QUERY = arg[8:]
+
+
+############################################################
+# 1 # find and print *.txt file ############################
+############################################################
+
+try:
+    for fname in listdir(".upload_files"):
+        if fname.endswith(".txt"):
+            with open(".upload_files/{}".format(fname)) as f:
+                print(f.read())
+except FileNotFoundError:
+    pass
+
+
+############################################################
+# 2 # query "COUNT stars" ##################################
+############################################################
+
+RESULT = execute_query(QUERY)
+print(RESULT)
+
+############################################################
+# 3 ########################################################
+############################################################
+
+sys.exit(CODE)