config reader for previous commit

services/comex_main_backend.py

@@ -184,6 +184,7 @@ def one_big_form():
                 # A) DB config + connection
                 reg_db = connect(
                     host=config['SQL_HOST'],
+                    port=int(config['SQL_PORT']),
                     user="root",   # TODO change db ownership to a comexreg user
                     passwd="very-safe-pass",
                     db="comex_shared"

services/tools.py

+"""
+utility functions
+"""
+__author__    = "CNRS"
+__copyright__ = "Copyright 2016 ISCPIF-CNRS"
+__email__     = "romain.loth@iscpif.fr"
+
+from configparser import ConfigParser
+from os           import environ, path
+
+CONFIGMENU = [
+            {"sec": 'main',       "var":'DEBUG_FLAG',   "def": True         },
+            {"sec": 'main',       "var":'COMEX_HOST',   "def": '0.0.0.0'    },
+            {"sec": 'main',       "var":'COMEX_PORT',   "def": '9090'       },
+            {"sec": 'routes',     "var":'USR_PREFIX',   "def": '/regcomex'  },
+            {"sec": 'services',   "var":'SQL_HOST',     "def": '172.17.0.2' },
+            {"sec": 'services',   "var":'SQL_PORT',     "def": '3306'       },
+            {"sec": 'services',   "var":'DOORS_HOST',   "def": '0.0.0.0'    },
+            {"sec": 'services',   "var":'DOORS_PORT',   "def": '8989'       }
+          ]
+
+
+def home_path():
+    """
+    we are in ./services so project home is the dirname of the parent
+    """
+    return path.dirname(path.dirname(path.realpath(__file__)))
+
+
+def read_config():
+    """
+    reads all global config vars trying in order:
+        1) the config file $HOME/parametres_comex.ini
+        2) env variables of the same name
+        3) hard-coded default values
+
+    output is a simple dict
+    """
+    out_dict = {}
+    our_home = home_path()
+
+    ini = ConfigParser()
+    ini.read(path.join(our_home, "parametres_comex.ini"))
+
+    # debug sections
+    # print("ini sections:", [sec for sec in ini.keys()])
+
+    # read ini file and use 2 fallbacks: env or default
+    for citem in CONFIGMENU:
+        section = citem['sec']
+        varname = citem['var']
+        default = citem['def']
+        is_bool = (type(default) == bool)
+        if section in ini and varname in ini[section]:
+            if is_bool:
+                out_dict[varname] = ini.getboolean(section, varname)
+            else:
+                out_dict[varname] = ini.get(section, varname)
+        elif varname in environ:
+            if is_bool:
+                out_dict[varname] = (environ[varname] == 'true')
+            else:
+                out_dict[varname] = environ[varname]
+        else:
+            out_dict[varname] = default
+
+    # also add our project home since we have it and we'll need it
+    out_dict['HOME'] = our_home
+
+    return out_dict