Configure the database backend in the config.ini

The database backend is currently configured in the 'db/backend_name'
file which is just another file that needs to be configured when setting
up or migrating a tracker instance. By moving this setting into the
config.ini it helps to reduce the number of files that need to be
configured and is more logical place for users to find the setting.

Author: jerrykan

doc/upgrading.txt

@@ -20,6 +20,30 @@ Contents:
 .. contents::
    :local:
 
+Migrating from 1.5.1 to 1.6.0
+=============================
+
+The ``db/backend_name`` file is no longer used to configure the database
+backend being used for a tracker. The backend is now configured in the
+``config.ini`` file using the ``backend`` option located in the ``[rdbms]``
+section. For example if ``db/backend_name`` file contains ``sqlite``, a new
+entry in the ``config.ini`` will need to be created::
+
+  [rdbms]
+
+  ...
+
+  # Database backend.
+  # Default:
+  backend = sqlite
+
+Once the ``config.ini`` file has been updated with the new ``backend`` option,
+you can safely delete the ``db/backend_name`` file.
+
+Note: the ``backend_name`` file may be located in a directory other than
+``db/`` if you have configured the ``database`` option in the ``[main]``
+section of the ``config.ini`` file to be something other than ``db``.
+
 Migrating from 1.5.0 to 1.5.1
 =============================
 

roundup/admin.py

@@ -421,9 +421,9 @@ def do_install(self, tracker_home, args):
         else:
             defns = {}
 
+        defns['rdbms_backend'] = backend
         # install!
         init.install(tracker_home, templates[template]['path'], settings=defns)
-        init.write_select_db(tracker_home, backend)
 
         print _("""
 ---------------------------------------------------------------------------
@@ -502,14 +502,9 @@ def do_initialise(self, tracker_home, args):
             if ok.strip().lower() != 'y':
                 return 0
 
-            backend = tracker.get_backend_name()
-
             # nuke it
             tracker.nuke()
 
-            # re-write the backend select file
-            init.write_select_db(tracker_home, backend, tracker.config.DATABASE)
-
         # GO
         tracker.init(password.Password(adminpw, config=tracker.config))
 

roundup/backends/back_anydbm.py

@@ -171,6 +171,10 @@ def __init__(self, config, journaltag=None):
         self.security = security.Security(self)
         os.umask(config.UMASK)
 
+        # make sure the database directory exists
+        if not os.path.isdir(self.config.DATABASE):
+            os.makedirs(self.config.DATABASE)
+
         # lock it
         lockfilenm = os.path.join(self.dir, 'lock')
         self.lockfile = locking.acquire_lock(lockfilenm)

roundup/backends/rdbms_common.py

@@ -185,6 +185,10 @@ def __init__(self, config, journaltag=None):
         self.stats = {'cache_hits': 0, 'cache_misses': 0, 'get_items': 0,
             'filtering': 0}
 
+        # make sure the database directory exists
+        if not os.path.isdir(self.config.DATABASE):
+            os.makedirs(self.config.DATABASE)
+
         # database lock
         self.lockfile = None
 

roundup/configuration.py

@@ -620,6 +620,8 @@ def str2value(self, value):
         (Option, 'name', 'roundup',
             "Name of the database to use.",
             ['MYSQL_DBNAME']),
+        (Option, 'backend', '',
+            "Database backend."),
         (NullableOption, 'host', 'localhost',
             "Database server host.",
             ['MYSQL_DBHOST']),

roundup/init.py

@@ -175,21 +175,4 @@ def saveTemplateInfo(dir, info):
     finally:
         f.close()
 
-def write_select_db(instance_home, backend, dbdir=None):
-    ''' Write the file that selects the backend for the tracker
-    '''
-    # dbdir is only supplied when AdminTool.do_initialise() invokes this
-    # function and the value is fetched from the tracker config which has
-    # already determined the correct path. This is bit of a hack, but it is
-    # likely this function will be removed in v1.6
-    if not dbdir:
-        dbdir = os.path.join(instance_home, 'db')
-    if not os.path.exists(dbdir):
-        os.makedirs(dbdir)
-    f = open(os.path.join(dbdir, 'backend_name'), 'w')
-    f.write(backend+'\n')
-    f.close()
-
-
-
 # vim: set filetype=python sts=4 sw=4 et si :

roundup/instance.py

@@ -30,6 +30,8 @@
 
 import os
 import sys
+import warnings
+
 from roundup import configuration, mailgw
 from roundup import hyperdb, backends, actions
 from roundup.cgi import client, templating
@@ -63,7 +65,31 @@ def __init__(self, tracker_home, optimize=0):
         self.load_interfaces()
         self.templates = templating.get_loader(self.config["TEMPLATES"],
             self.config["TEMPLATE_ENGINE"])
-        self.backend = backends.get_backend(self.get_backend_name())
+
+        rdbms_backend = self.config.RDBMS_BACKEND
+
+        # TODO: Remove in v1.7
+        # Provide some backwards compatability for existing Roundup instances
+        # that still define the backend type in 'db/backend_name' and warn the
+        # users they need to update their config.ini
+        if rdbms_backend == '':
+            filename = os.path.join(self.config.DATABASE, 'backend_name')
+            msg = """\n
+The 'backend_name' file is no longer used to configure the database backend
+used for the tracker.  Please read 'doc/upgrading.txt' to find out how to
+update your config.ini
+"""
+            try:
+                with file(filename) as backend_file:
+                    rdbms_backend = backend_file.readline().strip()
+
+                with warnings.catch_warnings():
+                    warnings.simplefilter("once", DeprecationWarning)
+                    warnings.warn(msg, DeprecationWarning, stacklevel=2)
+            except IOError:
+                pass
+
+        self.backend = backends.get_backend(rdbms_backend)
 
         if self.optimize:
             self.templates.precompile()
@@ -77,12 +103,6 @@ def __init__(self, tracker_home, optimize=0):
             # db_open is set to True after first open()
             self.db_open = 0
 
-    def get_backend_name(self):
-        f = file(os.path.join(self.config.DATABASE, 'backend_name'))
-        name = f.readline().strip()
-        f.close()
-        return name
-
     def open(self, name=None):
         # load the database schema
         # we cannot skip this part even if self.optimize is set

test/db_test_base.py

@@ -65,12 +65,11 @@ def setupTracker(dirname, backend="anydbm"):
                                        'roundup',
                                        'templates',
                                        'classic'))
-    init.write_select_db(dirname, backend)
+    config.RDBMS_BACKEND = backend
     config.save(os.path.join(dirname, 'config.ini'))
     tracker = instance.open(dirname)
     if tracker.exists():
         tracker.nuke()
-        init.write_select_db(dirname, backend)
     tracker.init(password.Password('sekrit'))
     return tracker