Merge lp:~patrickas/ensoft-sextant/environment_variables into lp:ensoft-sextant

[Patrick Stevens]

Add sextant.environment

Add a sextant.environment file to do any munging of paths required (so that other classes don't need to know about where they are installed). This should fix the inability to run Sextant Web from source (which happened because the resources folder is in a different place relative to sextant.web.server when installed from source vs. when installed by pip).

[Phil Connell (pconnell)]

review: Needs Fixing

[lp:~patrickas/ensoft-sextant/environment_variables]

11. By Patrick Stevens <email address hidden> on 2014-08-21

Bugfix: ConnectionError was not caught, presumably because it's a subclass of IOError.

12. By Patrick Stevens <email address hidden> on 2014-08-21

Docstring for sextant.environment; rename ENVIRONMENT_VAR to ENV_CONFIG_FILE.

13. By Patrick Stevens <email address hidden> on 2014-08-21

More docstring, and DRY on sextant.environment._find_folder

[Patrick Stevens (patrickas)]

Changes made.

[Phil Connell (pconnell)]

Couple more minor markups suggested.

review: Needs Fixing

[lp:~patrickas/ensoft-sextant/environment_variables]

14. By Patrick Stevens <email address hidden> on 2014-08-21

Clarify IOError when Neo4J server is not found; fix sextant.environment.__all__

[Phil Connell (pconnell)]

review: Approve

=== modified file 'src/sextant/__main__.py'
--- src/sextant/__main__.py	2014-08-19 16:01:31 +0000
+++ src/sextant/__main__.py	2014-08-21 13:03:35 +0000
@@ -21,6 +21,7 @@
 from . import update_db
 from . import query
 from . import db_api
+from . import environment
 
 
 # @@@ Logging level should be configurable (with some structure to setting up
@@ -45,12 +46,13 @@
 def get_config_file():
     # get the config file option for neo4j server location and web port number
     _ROOT = os.path.abspath(os.path.dirname(__file__))
+
     def get_data(path, file_name):
         return os.path.join(_ROOT, path, file_name)
 
-    home_config = os.path.expanduser(os.path.join("~", ".sextant.conf"))
-    env_config = os.environ.get("SEXTANT_CONFIG", "")
-    example_config = get_data('../etc', 'sextant.conf')
+    home_config = environment.HOME_CONFIG_FILE
+    env_config = os.environ.get(environment.ENV_CONFIG_FILE, "")
+    example_config = environment.DEFAULT_CONFIG_FILE
 
     try:
         conffile = next(p
@@ -58,13 +60,13 @@
                         if os.path.exists(p))
     except StopIteration:
         #No config files accessable
-        if "SEXTANT_CONFIG" in os.environ:
+        if environment.ENV_CONFIG_FILE in os.environ:
             #SEXTANT_CONFIG environment variable is set
-            log.error("SEXTANT_CONFIG file %r doesn't exist.", env_config)
+            log.error("{} file %r doesn't exist.".format(environment.ENV_CONFIG_FILE), env_config)
         log.error("Sextant requires a configuration file.")
         sys.exit(1)
 
-    log.info("Sextant is using config file %s", conffile)
+    log.info("Sextant is using config file {}".format(conffile))
     return conffile
 
 conffile = get_config_file()
@@ -72,9 +74,9 @@
 conf = ConfigParser.ConfigParser()
 conf.read(conffile)
 
-#remote_neo4j = 'http://localhost:7474'
-#web_port = 2905
-#common_def = 10  # definition of a 'common' node
+remote_neo4j = 'http://localhost:7474'
+web_port = 2905
+common_def = 10  # definition of a 'common' node
 try:
     options = conf.options('Neo4j')
 except ConfigParser.NoSectionError:
@@ -179,11 +181,15 @@
         update_db.upload_program(namespace.input_file[0],
                                  namespace.remote_neo4j,
                                  alternative_name, not_object_file)
-    except IOError: # in case of Python 2, where FileNotFoundError is undefined
-        logging.error('Input file {} was not found.'.format(namespace.input_file[0]))
     except requests.exceptions.ConnectionError as e:
         logging.error('Connection error to server {}: {}'.format(namespace.remote_neo4j,
                                                                  e))
+
+    except IOError as e:
+        # in case of Python 2, where FileNotFoundError is undefined
+        logging.error('Input file {} was not found.'.format(namespace.input_file[0]))
+        logging.error(e)
+        logging.debug(e, exc_info=True)
     except ValueError as e:
         logging.error(e)
 

=== added file 'src/sextant/environment.py'
--- src/sextant/environment.py	1970-01-01 00:00:00 +0000
+++ src/sextant/environment.py	2014-08-21 13:03:35 +0000
@@ -0,0 +1,43 @@
+# -----------------------------------------
+# Sextant
+# Copyright 2014, Ensoft Ltd.
+# Author: Patrick Stevens
+# -----------------------------------------
+# Define 'environment' variables for 'where we are located'.
+
+"""
+Defines standard Sextant locations.
+"""
+
+__all__ = ("RESOURCES_DIR", "DEFAULT_CONFIG_FILE", "ENV_CONFIG_FILE", 
+           "HOME_CONFIG_FILE")
+
+import os
+
+
+RESOURCES_DIR = ""         # where the resources folder is located
+DEFAULT_CONFIG_FILE = ""  # where the bundled config file is located
+ENV_CONFIG_FILE = "SEXTANT_CONFIG"  # name of the config-file env var to seek
+# path to user-specific configuration file to seek
+HOME_CONFIG_FILE = os.path.expanduser(os.path.join("~", ".sextant.conf"))
+
+
+def _find_folder(name):
+    """
+    Given a folder name, returns the absolute path to that folder.
+    If the folder could not be found in the standard installation places,
+    raises IOError.
+    """
+    path = os.path.abspath(os.path.dirname(__file__))
+    trial = path
+    for level in range(2):  # search both .. and ../..
+        trial = os.path.join(trial, '..')
+        if os.path.isdir(os.path.join(trial, name)):
+            return os.path.abspath(os.path.join(trial, name))
+
+    raise IOError("Could not find {} folder.".format(name))
+
+
+RESOURCES_DIR = _find_folder('resources')
+_conf_path = _find_folder('etc')
+DEFAULT_CONFIG_FILE = os.path.join(_conf_path, 'sextant.conf')

=== modified file 'src/sextant/web/server.py'
--- src/sextant/web/server.py	2014-08-19 09:20:45 +0000
+++ src/sextant/web/server.py	2014-08-21 13:03:35 +0000
@@ -20,6 +20,7 @@
 
 import sextant.db_api as db_api
 import sextant.export as export
+import sextant.environment as environment
 import tempfile
 import subprocess
 
@@ -298,9 +299,7 @@
     global database_url
     database_url = input_database_url
     # serve static directory at root
-    root = File(os.path.join(
-        os.path.dirname(os.path.abspath(__file__)),
-        "..", "..", "..", "resources", "sextant", "web"))
+    root = File(os.path.join(environment.RESOURCES_DIR, 'sextant', 'web'))
 
     # serve a dynamic Echoer webpage at /echoer.html
     root.putChild("echoer.html", Echoer())