Source Code for Module dak.update_db

  1  #! /usr/bin/env python3 
  2   
  3  """Database Update Main Script 
  4   
  5  @contact: Debian FTP Master <ftpmaster@debian.org> 
  6  # Copyright (C) 2008  Michael Casadevall <mcasadevall@debian.org> 
  7  @license: GNU General Public License version 2 or later 
  8  """ 
  9   
 10  # This program is free software; you can redistribute it and/or modify 
 11  # it under the terms of the GNU General Public License as published by 
 12  # the Free Software Foundation; either version 2 of the License, or 
 13  # (at your option) any later version. 
 14   
 15  # This program is distributed in the hope that it will be useful, 
 16  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
 17  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 18  # GNU General Public License for more details. 
 19   
 20  # You should have received a copy of the GNU General Public License 
 21  # along with this program; if not, write to the Free Software 
 22  # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 23   
 24  ################################################################################ 
 25   
 26  # <Ganneff> when do you have it written? 
 27  # <NCommander> Ganneff, after you make my debian account 
 28  # <Ganneff> blackmail wont work 
 29  # <NCommander> damn it 
 30   
 31  ################################################################################ 
 32   
 33  import errno 
 34  import fcntl 
 35  import os 
 36  import sys 
 37  import time 
 38  from glob import glob 
 39  from re import findall 
 40   
 41  import apt_pkg 
 42  import psycopg2 
 43   
 44  from daklib import utils 
 45  from daklib.config import Config 
 46  from daklib.dak_exceptions import DBUpdateError 
 47  from daklib.daklog import Logger 
 48   
 49  ################################################################################ 
 50   
 51  Cnf = None 
 52   
 53  ################################################################################ 
 54   
 55   
 56 -class UpdateDB: 
 57 -    def usage(self, exit_code=0): 
 58          print( 
 59              """Usage: dak update-db 
 60  Updates dak's database schema to the lastest version. You should disable crontabs while this is running 
 61   
 62    -h, --help                show this help and exit. 
 63    -y, --yes                 do not ask for confirmation""" 
 64          ) 
 65          sys.exit(exit_code) 
 66   
 67      ################################################################################ 
 68   
 69 -    def update_db_to_zero(self): 
 70          """This function will attempt to update a pre-zero database schema to zero""" 
 71   
 72          # First, do the sure thing, and create the configuration table 
 73          try: 
 74              print("Creating configuration table ...") 
 75              c = self.db.cursor() 
 76              c.execute( 
 77                  """CREATE TABLE config ( 
 78                                    id SERIAL PRIMARY KEY NOT NULL, 
 79                                    name TEXT UNIQUE NOT NULL, 
 80                                    value TEXT 
 81                                  );""" 
 82              ) 
 83              c.execute( 
 84                  "INSERT INTO config VALUES ( nextval('config_id_seq'), 'db_revision', '0')" 
 85              ) 
 86              self.db.commit() 
 87   
 88          except psycopg2.ProgrammingError: 
 89              self.db.rollback() 
 90              print("Failed to create configuration table.") 
 91              print("Can the projectB user CREATE TABLE?") 
 92              print("") 
 93              print("Aborting update.") 
 94              sys.exit(-255) 
 95   
 96      ################################################################################ 
 97   
 98 -    def get_db_rev(self): 
 99          # We keep database revision info the config table 
100          # Try and access it 
101   
102          try: 
103              c = self.db.cursor() 
104              c.execute("SELECT value FROM config WHERE name = 'db_revision';") 
105              return c.fetchone()[0] 
106   
107          except psycopg2.ProgrammingError: 
108              # Whoops .. no config table ... 
109              self.db.rollback() 
110              print( 
111                  "No configuration table found, assuming dak database revision to be pre-zero" 
112              ) 
113              return -1 
114   
115      ################################################################################ 
116   
117 -    def get_transaction_id(self): 
118          """ 
119          Returns the current transaction id as a string. 
120          """ 
121          cursor = self.db.cursor() 
122          cursor.execute("SELECT txid_current();") 
123          id = cursor.fetchone()[0] 
124          cursor.close() 
125          return id 
126   
127      ################################################################################ 
128   
129 -    def update_db(self): 
130          # Ok, try and find the configuration table 
131          print("Determining dak database revision ...") 
132          cnf = Config() 
133          logger = Logger("update-db") 
134          modules = [] 
135   
136          try: 
137              # Build a connect string 
138              if "DB::Service" in cnf: 
139                  connect_str = "service=%s" % cnf["DB::Service"] 
140              else: 
141                  connect_str = "dbname=%s" % (cnf["DB::Name"]) 
142                  if "DB::Host" in cnf and cnf["DB::Host"] != "": 
143                      connect_str += " host=%s" % (cnf["DB::Host"]) 
144                  if "DB::Port" in cnf and cnf["DB::Port"] != "-1": 
145                      connect_str += " port=%d" % (int(cnf["DB::Port"])) 
146   
147              self.db = psycopg2.connect(connect_str) 
148   
149              db_role = cnf.get("DB::Role") 
150              if db_role: 
151                  self.db.cursor().execute('SET ROLE "{}"'.format(db_role)) 
152   
153          except Exception as e: 
154              print("FATAL: Failed connect to database (%s)" % str(e)) 
155              sys.exit(1) 
156   
157          database_revision = int(self.get_db_rev()) 
158          logger.log(["transaction id before update: %s" % self.get_transaction_id()]) 
159   
160          if database_revision == -1: 
161              print("dak database schema predates update-db.") 
162              print("") 
163              print( 
164                  "This script will attempt to upgrade it to the lastest, but may fail." 
165              ) 
166              print( 
167                  "Please make sure you have a database backup handy. If you don't, press Ctrl-C now!" 
168              ) 
169              print("") 
170              print("Continuing in five seconds ...") 
171              time.sleep(5) 
172              print("") 
173              print("Attempting to upgrade pre-zero database to zero") 
174   
175              self.update_db_to_zero() 
176              database_revision = 0 
177   
178          dbfiles = glob(os.path.join(os.path.dirname(__file__), "dakdb/update*.py")) 
179          required_database_schema = max( 
180              int(x) for x in findall(r"update(\d+).py", " ".join(dbfiles)) 
181          ) 
182   
183          print("dak database schema at %d" % database_revision) 
184          print("dak version requires schema %d" % required_database_schema) 
185   
186          if database_revision < required_database_schema: 
187              print("\nUpdates to be applied:") 
188              for i in range(database_revision, required_database_schema): 
189                  i += 1 
190                  dakdb = __import__("dakdb", globals(), locals(), ["update" + str(i)]) 
191                  update_module = getattr(dakdb, "update" + str(i)) 
192                  print( 
193                      "Update %d: %s" 
194                      % (i, next(s for s in update_module.__doc__.split("\n") if s)) 
195                  ) 
196                  modules.append((update_module, i)) 
197              if not Config().find_b("Update-DB::Options::Yes", False): 
198                  prompt = "\nUpdate database? (y/N) " 
199                  answer = utils.input_or_exit(prompt) 
200                  if answer.upper() != "Y": 
201                      sys.exit(0) 
202          else: 
203              print("no updates required") 
204              logger.log(["no updates required"]) 
205              sys.exit(0) 
206   
207          for module in modules: 
208              (update_module, i) = module 
209              try: 
210                  update_module.do_update(self) 
211                  message = "updated database schema from %d to %d" % ( 
212                      database_revision, 
213                      i, 
214                  ) 
215                  print(message) 
216                  logger.log([message]) 
217              except DBUpdateError as e: 
218                  # Seems the update did not work. 
219                  print( 
220                      "Was unable to update database schema from %d to %d." 
221                      % (database_revision, i) 
222                  ) 
223                  print("The error message received was %s" % (e)) 
224                  logger.log(["DB Schema upgrade failed"]) 
225                  logger.close() 
226                  utils.fubar("DB Schema upgrade failed") 
227              database_revision += 1 
228          logger.close() 
229   
230      ################################################################################ 
231   
232 -    def init(self): 
233          cnf = Config() 
234          arguments = [ 
235              ("h", "help", "Update-DB::Options::Help"), 
236              ("y", "yes", "Update-DB::Options::Yes"), 
237          ] 
238          for i in ["help"]: 
239              key = "Update-DB::Options::%s" % i 
240              if key not in cnf: 
241                  cnf[key] = "" 
242   
243          arguments = apt_pkg.parse_commandline(cnf.Cnf, arguments, sys.argv) 
244   
245          options = cnf.subtree("Update-DB::Options") 
246          if options["Help"]: 
247              self.usage() 
248          elif arguments: 
249              utils.warn("dak update-db takes no arguments.") 
250              self.usage(exit_code=1) 
251   
252          try: 
253              if os.path.isdir(cnf["Dir::Lock"]): 
254                  lock_fd = os.open( 
255                      os.path.join(cnf["Dir::Lock"], "daily.lock"), 
256                      os.O_RDONLY | os.O_CREAT, 
257                  ) 
258                  fcntl.flock(lock_fd, fcntl.LOCK_EX | fcntl.LOCK_NB) 
259              else: 
260                  utils.warn("Lock directory doesn't exist yet - not locking") 
261          except OSError as e: 
262              if e.errno in (errno.EACCES, errno.EAGAIN): 
263                  utils.fubar( 
264                      "Couldn't obtain lock, looks like archive is doing something, try again later." 
265                  ) 
266              else: 
267                  raise 
268   
269          self.update_db() 
270   
271   
272  ################################################################################ 
273   
274  if __name__ == "__main__": 
275      app = UpdateDB() 
276      app.init() 
277   
278   
279 -def main(): 
280      app = UpdateDB() 
281      app.init() 
282