1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
|
import logging
import traceback
from django.db.models.fields import NOT_PROVIDED
from django.db import connection, DatabaseError, backend, models
from django.core.management.color import no_style
from django.core.management.sql import sql_create
import django.core.management
import Bcfg2.settings
logger = logging.getLogger(__name__)
def _quote(value):
"""
Quote a string to use as a table name or column
"""
return backend.DatabaseOperations().quote_name(value)
def _rebuild_sqlite_table(model):
"""Sqlite doesn't support most alter table statments. This streamlines the
rebuild process"""
try:
cursor = connection.cursor()
table_name = model._meta.db_table
# Build create staement from django
model._meta.db_table = "%s_temp" % table_name
sql, references = connection.creation.sql_create_model(model, no_style())
columns = ",".join([_quote(f.column) \
for f in model._meta.fields])
# Create a temp table
[cursor.execute(s) for s in sql]
# Fill the table
tbl_name = _quote(table_name)
tmp_tbl_name = _quote(model._meta.db_table)
# Reset this
model._meta.db_table = table_name
cursor.execute("insert into %s(%s) select %s from %s;" % (
tmp_tbl_name,
columns,
columns,
tbl_name))
cursor.execute("drop table %s" % tbl_name)
# Call syncdb to create the table again
django.core.management.call_command("syncdb", interactive=False, verbosity=0)
# syncdb closes our cursor
cursor = connection.cursor()
# Repopulate
cursor.execute('insert into %s(%s) select %s from %s;' % (tbl_name,
columns,
columns,
tmp_tbl_name))
cursor.execute('DROP TABLE %s;' % tmp_tbl_name)
except DatabaseError:
logger.error("Failed to rebuild sqlite table %s" % table_name, exc_info=1)
raise UpdaterRoutineException
class UpdaterRoutineException(Exception):
pass
class UpdaterRoutine(object):
"""Base for routines."""
def __init__(self):
pass
def __str__(self):
return __name__
def run(self):
"""Called to execute the action"""
raise UpdaterRoutineException
class AddColumns(UpdaterRoutine):
"""
Routine to add new columns to an existing model
"""
def __init__(self, model):
self.model = model
self.model_name = model.__name__
def __str__(self):
return "Add new columns for model %s" % self.model_name
def run(self):
try:
cursor = connection.cursor()
except DatabaseError:
logger.error("Failed to connect to the db")
raise UpdaterRoutineException
try:
desc = {}
for d in connection.introspection.get_table_description(cursor,
self.model._meta.db_table):
desc[d[0]] = d
except DatabaseError:
logger.error("Failed to get table description", exc_info=1)
raise UpdaterRoutineException
for field in self.model._meta.fields:
if field.column in desc:
continue
logger.debug("Column %s does not exist yet" % field.column)
if field.default == NOT_PROVIDED:
logger.error("Cannot add a column with out a default value")
raise UpdaterRoutineException
sql = "ALTER TABLE %s ADD %s %s NOT NULL DEFAULT " % (
_quote(self.model._meta.db_table),
_quote(field.column), field.db_type(), )
db_engine = Bcfg2.settings.DATABASES['default']['ENGINE']
if db_engine == 'django.db.backends.sqlite3':
sql += _quote(field.default)
sql_values = ()
else:
sql += '%s'
sql_values = (field.default, )
try:
cursor.execute(sql, sql_values)
logger.debug("Added column %s to %s" %
(field.column, self.model._meta.db_table))
except DatabaseError:
logger.error("Unable to add column %s" % field.column)
raise UpdaterRoutineException
class RebuildTable(UpdaterRoutine):
"""
Rebuild the table for an existing model. Use this if field types have changed.
"""
def __init__(self, model, columns):
self.model = model
self.model_name = model.__name__
if type(columns) == str:
self.columns = [columns]
elif type(columns) in (tuple, list):
self.columns = columns
else:
logger.error("Columns must be a str, tuple, or list")
raise UpdaterRoutineException
def __str__(self):
return "Rebuild columns for model %s" % self.model_name
def run(self):
try:
cursor = connection.cursor()
except DatabaseError:
logger.error("Failed to connect to the db")
raise UpdaterRoutineException
db_engine = Bcfg2.settings.DATABASES['default']['ENGINE']
if db_engine == 'django.db.backends.sqlite3':
""" Sqlite is a special case. Altering columns is not supported. """
_rebuild_sqlite_table(self.model)
return
if db_engine == 'django.db.backends.mysql':
modify_cmd = 'MODIFY '
else:
modify_cmd = 'ALTER COLUMN '
col_strings = []
for column in self.columns:
col_strings.append("%s %s %s" % ( \
modify_cmd,
_quote(column),
self.model._meta.get_field(column).db_type()
))
try:
cursor.execute('ALTER TABLE %s %s' %
(_quote(self.model._meta.db_table), ", ".join(col_strings)))
except DatabaseError:
logger.debug("Failed modify table %s" % self.model._meta.db_table)
raise UpdaterRoutineException
class RemoveColumns(RebuildTable):
"""
Routine to remove columns from an existing model
"""
def __init__(self, model, columns):
super(RemoveColumns, self).__init__(model, columns)
def __str__(self):
return "Remove columns from model %s" % self.model_name
def run(self):
try:
cursor = connection.cursor()
except DatabaseError:
logger.error("Failed to connect to the db")
raise UpdaterRoutineException
try:
columns = [d[0] for d in connection.introspection.get_table_description(cursor,
self.model._meta.db_table)]
except DatabaseError:
logger.error("Failed to get table description", exc_info=1)
raise UpdaterRoutineException
for column in self.columns:
if column not in columns:
logger.warning("Cannot drop column %s: does not exist" % column)
continue
logger.debug("Dropping column %s" % column)
db_engine = Bcfg2.DATABASES['default']['ENGINE']
if db_engine == 'django.db.backends.sqlite3':
_rebuild_sqlite_table(self.model)
else:
sql = "alter table %s drop column %s" % \
(_quote(self.model._meta.db_table), _quote(column), )
try:
cursor.execute(sql)
except DatabaseError:
logger.debug("Failed to drop column %s from %s" %
(column, self.model._meta.db_table))
raise UpdaterRoutineException
class DropTable(UpdaterRoutine):
"""
Drop a table
"""
def __init__(self, table_name):
self.table_name = table_name
def __str__(self):
return "Drop table %s" % self.table_name
def run(self):
try:
cursor = connection.cursor()
cursor.execute('DROP TABLE %s' % _quote(self.table_name))
except DatabaseError:
logger.error("Failed to drop table: %s" %
traceback.format_exc().splitlines()[-1])
raise UpdaterRoutineException
class UpdaterCallable(UpdaterRoutine):
"""Helper for routines. Basically delays execution"""
def __init__(self, fn):
self.fn = fn
self.args = []
self.kwargs = {}
def __call__(self, *args, **kwargs):
self.args = args
self.kwargs = kwargs
return self
def __str__(self):
return self.fn.__name__
def run(self):
self.fn(*self.args, **self.kwargs)
def updatercallable(fn):
"""Decorator for UpdaterCallable. Use for any function passed
into the fixes list"""
return UpdaterCallable(fn)
|
