1.1 --- a/imiptools/__init__.py	Tue Oct 17 23:30:18 2017 +0200
     1.2 +++ b/imiptools/__init__.py	Wed Oct 18 00:18:37 2017 +0200
     1.3 @@ -25,7 +25,8 @@
     1.4  from imiptools.content import handle_itip_part
     1.5  from imiptools.data import get_address, get_addresses, get_uri
     1.6  from imiptools.mail import Messenger
     1.7 -from imiptools.stores import get_store, get_publisher, get_journal
     1.8 +from imiptools.stores import get_store, get_publisher, get_journal, \
     1.9 +                             StoreInitialisationError
    1.10  import sys, os
    1.11  
    1.12  # Postfix exit codes.
    1.13 @@ -71,15 +72,21 @@
    1.14  
    1.15      def get_publisher(self):
    1.16  
    1.17 -        "Return any configured publisher or None if not explicitly configured."
    1.18 +        "Return any configured publisher or None if not configured."
    1.19  
    1.20 -        return self.publishing_dir and get_publisher(self.publishing_dir) or None
    1.21 +        try:
    1.22 +            return get_publisher(self.publishing_dir)
    1.23 +        except StoreInitialisationError:
    1.24 +            return None
    1.25  
    1.26      def get_journal(self):
    1.27  
    1.28 -        "Return any configured journal or None if not explicitly configured."
    1.29 +        "Return any configured journal or None if not configured."
    1.30  
    1.31 -        return self.journal_dir and get_journal(self.store_type, self.journal_dir) or None
    1.32 +        try:
    1.33 +            return get_journal(self.store_type, self.journal_dir)
    1.34 +        except StoreInitialisationError:
    1.35 +            return None
    1.36  
    1.37      def process(self, f, original_recipients):
    1.38  

     2.1 --- a/imiptools/stores/__init__.py	Tue Oct 17 23:30:18 2017 +0200
     2.2 +++ b/imiptools/stores/__init__.py	Wed Oct 18 00:18:37 2017 +0200
     2.3 @@ -20,6 +20,7 @@
     2.4  """
     2.5  
     2.6  from imiptools.config import settings
     2.7 +from imiptools.stores.common import StoreInitialisationError
     2.8  from imiptools.stores.manifest import stores
     2.9  
    2.10  # Access functions.
    2.11 @@ -42,7 +43,7 @@
    2.12      """
    2.13  
    2.14      return stores["file"].Publisher(
    2.15 -        publishing_dir or settings["PUBLISHING_DIR"])
    2.16 +        publishing_dir or settings["PUBLISH_DIR"])
    2.17  
    2.18  def get_journal(store_type=None, journal_dir=None):
    2.19  

     3.1 --- a/imiptools/stores/common.py	Tue Oct 17 23:30:18 2017 +0200
     3.2 +++ b/imiptools/stores/common.py	Wed Oct 18 00:18:37 2017 +0200
     3.3 @@ -21,6 +21,12 @@
     3.4  
     3.5  from imiptools.dates import format_datetime, get_datetime
     3.6  
     3.7 +class StoreInitialisationError(Exception):
     3.8 +
     3.9 +    "An error occurring when the initialisation of a store fails."
    3.10 +
    3.11 +    pass
    3.12 +
    3.13  class StoreBase:
    3.14  
    3.15      "The core operations of a data store."

     4.1 --- a/imiptools/stores/database/postgresql.py	Tue Oct 17 23:30:18 2017 +0200
     4.2 +++ b/imiptools/stores/database/postgresql.py	Wed Oct 18 00:18:37 2017 +0200
     4.3 @@ -20,6 +20,7 @@
     4.4  """
     4.5  
     4.6  from imiptools.config import settings
     4.7 +from imiptools.stores.common import StoreInitialisationError
     4.8  from imiptools.stores.database.common import DatabaseStore, DatabaseJournal
     4.9  import psycopg2
    4.10  
    4.11 @@ -34,7 +35,11 @@
    4.12  
    4.13          "Interpret 'store_dir' as a connection string."
    4.14  
    4.15 -        connection = psycopg2.connect(store_dir or STORE_DIR)
    4.16 +        try:
    4.17 +            connection = psycopg2.connect(store_dir or STORE_DIR)
    4.18 +        except psycopg2.OperationalError, exc:
    4.19 +            raise StoreInitialisationError, exc
    4.20 +
    4.21          connection.autocommit = True
    4.22          DatabaseStore.__init__(self, connection, psycopg2.paramstyle)
    4.23  
    4.24 @@ -54,7 +59,11 @@
    4.25  
    4.26          "Interpret 'store_dir' as a connection string."
    4.27  
    4.28 -        connection = psycopg2.connect(store_dir or JOURNAL_DIR)
    4.29 +        try:
    4.30 +            connection = psycopg2.connect(store_dir or JOURNAL_DIR)
    4.31 +        except psycopg2.OperationalError, exc:
    4.32 +            raise StoreInitialisationError, exc
    4.33 +
    4.34          connection.autocommit = True
    4.35          DatabaseJournal.__init__(self, connection, psycopg2.paramstyle)
    4.36  

     5.1 --- a/imiptools/stores/file.py	Tue Oct 17 23:30:18 2017 +0200
     5.2 +++ b/imiptools/stores/file.py	Wed Oct 18 00:18:37 2017 +0200
     5.3 @@ -19,7 +19,8 @@
     5.4  this program.  If not, see <http://www.gnu.org/licenses/>.
     5.5  """
     5.6  
     5.7 -from imiptools.stores.common import StoreBase, PublisherBase, JournalBase
     5.8 +from imiptools.stores.common import StoreBase, PublisherBase, JournalBase, \
     5.9 +                                    StoreInitialisationError
    5.10  
    5.11  from datetime import datetime
    5.12  from imiptools.config import settings
    5.13 @@ -62,7 +63,10 @@
    5.14      "A file store of tabular free/busy data and objects."
    5.15  
    5.16      def __init__(self, store_dir=None):
    5.17 -        FileBase.__init__(self, store_dir or STORE_DIR)
    5.18 +        try:
    5.19 +            FileBase.__init__(self, store_dir or STORE_DIR)
    5.20 +        except OSError, exc:
    5.21 +            raise StoreInitialisationError, exc
    5.22  
    5.23      # Store object access.
    5.24  
    5.25 @@ -707,7 +711,10 @@
    5.26      "A publisher of objects."
    5.27  
    5.28      def __init__(self, store_dir=None):
    5.29 -        FileBase.__init__(self, store_dir or PUBLISH_DIR)
    5.30 +        try:
    5.31 +            FileBase.__init__(self, store_dir or PUBLISH_DIR)
    5.32 +        except OSError, exc:
    5.33 +            raise StoreInitialisationError, exc
    5.34  
    5.35      def set_freebusy(self, user, freebusy):
    5.36