Initial commit; enough to prove concepts at least

was able to bootstrap a complete machine with this, although there's lots
missing yet...

rattail_fabric2/postgresql.py

@@ -0,0 +1,96 @@
+# -*- coding: utf-8; -*-
+################################################################################
+#
+#  Rattail -- Retail Software Framework
+#  Copyright © 2010-2018 Lance Edgar
+#
+#  This file is part of Rattail.
+#
+#  Rattail is free software: you can redistribute it and/or modify it under the
+#  terms of the GNU General Public License as published by the Free Software
+#  Foundation, either version 3 of the License, or (at your option) any later
+#  version.
+#
+#  Rattail 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 General Public License for more
+#  details.
+#
+#  You should have received a copy of the GNU General Public License along with
+#  Rattail.  If not, see <http://www.gnu.org/licenses/>.
+#
+################################################################################
+"""
+Fabric Library for PostgreSQL
+"""
+
+from __future__ import unicode_literals, absolute_import
+
+from rattail_fabric2 import apt
+
+
+def install(c):
+    """
+    Install the PostgreSQL database service
+    """
+    apt.install(c, 'postgresql')
+
+
+def sql(c, sql, database='', port=None):
+    """
+    Execute some SQL as the 'postgres' user.
+    """
+    cmd = 'sudo -u postgres psql {port} --tuples-only --no-align --command="{sql}" {database}'.format(
+        port='--port={}'.format(port) if port else '',
+        sql=sql, database=database)
+    return c.sudo(cmd, shell=False)
+
+
+def user_exists(c, name, port=None):
+    """
+    Determine if a given PostgreSQL user exists.
+    """
+    user = sql(c, "SELECT rolname FROM pg_roles WHERE rolname = '{0}'".format(name), port=port).stdout.strip()
+    return bool(user)
+
+
+def create_user(c, name, password=None, port=None, checkfirst=True, createdb=False):
+    """
+    Create a PostgreSQL user account.
+    """
+    if not checkfirst or not user_exists(c, name, port=port):
+        c.sudo('sudo -u postgres createuser {port} {createdb} --no-createrole --no-superuser {name}'.format(
+            port='--port={}'.format(port) if port else '',
+            createdb='--{}createdb'.format('' if createdb else 'no-'),
+            name=name))
+        if password:
+            set_user_password(c, name, password, port=port)
+
+
+def set_user_password(c, name, password, port=None):
+    """
+    Set the password for a PostgreSQL user account
+    """
+    # TODO: probably should figure out how to suppress echo for this command
+    # with hide('running'):
+    sql(c, "ALTER USER \\\"{}\\\" PASSWORD '{}';".format(name, password), port=port)
+
+
+def db_exists(c, name, port=None):
+    """
+    Determine if a given PostgreSQL database exists.
+    """
+    db = sql(c, "SELECT datname FROM pg_database WHERE datname = '{0}'".format(name), port=port).stdout.strip()
+    return db == name
+
+
+def create_db(c, name, owner=None, port=None, checkfirst=True):
+    """
+    Create a PostgreSQL database.
+    """
+    if not checkfirst or not db_exists(c, name, port=port):
+        cmd = 'sudo -u postgres createdb {port} {owner} {name}'.format(
+            port='--port={}'.format(port) if port else '',
+            owner='--owner={}'.format(owner) if owner else '',
+            name=name)
+        c.sudo(cmd)