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 psycopg2 
 34  import sys 
 35  import fcntl 
 36  import os 
 37  import apt_pkg 
 38  import time 
 39  import errno 
 40  from glob import glob 
 41  from re import findall 
 42   
 43  from daklib import utils 
 44  from daklib.config import Config 
 45  from daklib.dak_exceptions import DBUpdateError 
 46  from daklib.daklog import Logger 
 47   
 48  ################################################################################ 
 49   
 50  Cnf = None 
 51   
 52  ################################################################################ 
 53   
 54   
 55 -class UpdateDB: 
 56 -    def usage(self, exit_code=0): 
 57          print("""Usage: dak update-db 
 58  Updates dak's database schema to the lastest version. You should disable crontabs while this is running 
 59   
 60    -h, --help                show this help and exit. 
 61    -y, --yes                 do not ask for confirmation""") 
 62          sys.exit(exit_code) 
 63   
 64  ################################################################################ 
 65   
 66 -    def update_db_to_zero(self): 
 67          """ This function will attempt to update a pre-zero database schema to zero """ 
 68   
 69          # First, do the sure thing, and create the configuration table 
 70          try: 
 71              print("Creating configuration table ...") 
 72              c = self.db.cursor() 
 73              c.execute("""CREATE TABLE config ( 
 74                                    id SERIAL PRIMARY KEY NOT NULL, 
 75                                    name TEXT UNIQUE NOT NULL, 
 76                                    value TEXT 
 77                                  );""") 
 78              c.execute("INSERT INTO config VALUES ( nextval('config_id_seq'), 'db_revision', '0')") 
 79              self.db.commit() 
 80   
 81          except psycopg2.ProgrammingError: 
 82              self.db.rollback() 
 83              print("Failed to create configuration table.") 
 84              print("Can the projectB user CREATE TABLE?") 
 85              print("") 
 86              print("Aborting update.") 
 87              sys.exit(-255) 
 88   
 89  ################################################################################ 
 90   
 91 -    def get_db_rev(self): 
 92          # We keep database revision info the config table 
 93          # Try and access it 
 94   
 95          try: 
 96              c = self.db.cursor() 
 97              q = c.execute("SELECT value FROM config WHERE name = 'db_revision';") 
 98              return c.fetchone()[0] 
 99   
100          except psycopg2.ProgrammingError: 
101              # Whoops .. no config table ... 
102              self.db.rollback() 
103              print("No configuration table found, assuming dak database revision to be pre-zero") 
104              return -1 
105   
106  ################################################################################ 
107   
108 -    def get_transaction_id(self): 
109          ''' 
110          Returns the current transaction id as a string. 
111          ''' 
112          cursor = self.db.cursor() 
113          cursor.execute("SELECT txid_current();") 
114          id = cursor.fetchone()[0] 
115          cursor.close() 
116          return id 
117   
118  ################################################################################ 
119   
120 -    def update_db(self): 
121          # Ok, try and find the configuration table 
122          print("Determining dak database revision ...") 
123          cnf = Config() 
124          logger = Logger('update-db') 
125          modules = [] 
126   
127          try: 
128              # Build a connect string 
129              if "DB::Service" in cnf: 
130                  connect_str = "service=%s" % cnf["DB::Service"] 
131              else: 
132                  connect_str = "dbname=%s" % (cnf["DB::Name"]) 
133                  if "DB::Host" in cnf and cnf["DB::Host"] != '': 
134                      connect_str += " host=%s" % (cnf["DB::Host"]) 
135                  if "DB::Port" in cnf and cnf["DB::Port"] != '-1': 
136                      connect_str += " port=%d" % (int(cnf["DB::Port"])) 
137   
138              self.db = psycopg2.connect(connect_str) 
139   
140              db_role = cnf.get("DB::Role") 
141              if db_role: 
142                  self.db.cursor().execute('SET ROLE "{}"'.format(db_role)) 
143   
144          except Exception as e: 
145              print("FATAL: Failed connect to database (%s)" % str(e)) 
146              sys.exit(1) 
147   
148          database_revision = int(self.get_db_rev()) 
149          logger.log(['transaction id before update: %s' % self.get_transaction_id()]) 
150   
151          if database_revision == -1: 
152              print("dak database schema predates update-db.") 
153              print("") 
154              print("This script will attempt to upgrade it to the lastest, but may fail.") 
155              print("Please make sure you have a database backup handy. If you don't, press Ctrl-C now!") 
156              print("") 
157              print("Continuing in five seconds ...") 
158              time.sleep(5) 
159              print("") 
160              print("Attempting to upgrade pre-zero database to zero") 
161   
162              self.update_db_to_zero() 
163              database_revision = 0 
164   
165          dbfiles = glob(os.path.join(os.path.dirname(__file__), 'dakdb/update*.py')) 
166          required_database_schema = max(int(x) for x in findall(r'update(\d+).py', " ".join(dbfiles))) 
167   
168          print("dak database schema at %d" % database_revision) 
169          print("dak version requires schema %d" % required_database_schema) 
170   
171          if database_revision < required_database_schema: 
172              print("\nUpdates to be applied:") 
173              for i in range(database_revision, required_database_schema): 
174                  i += 1 
175                  dakdb = __import__("dakdb", globals(), locals(), ['update' + str(i)]) 
176                  update_module = getattr(dakdb, "update" + str(i)) 
177                  print("Update %d: %s" % (i, next(s for s in update_module.__doc__.split("\n") if s))) 
178                  modules.append((update_module, i)) 
179              if not Config().find_b("Update-DB::Options::Yes", False): 
180                  prompt = "\nUpdate database? (y/N) " 
181                  answer = utils.input_or_exit(prompt) 
182                  if answer.upper() != 'Y': 
183                      sys.exit(0) 
184          else: 
185              print("no updates required") 
186              logger.log(["no updates required"]) 
187              sys.exit(0) 
188   
189          for module in modules: 
190              (update_module, i) = module 
191              try: 
192                  update_module.do_update(self) 
193                  message = "updated database schema from %d to %d" % (database_revision, i) 
194                  print(message) 
195                  logger.log([message]) 
196              except DBUpdateError as e: 
197                  # Seems the update did not work. 
198                  print("Was unable to update database schema from %d to %d." % (database_revision, i)) 
199                  print("The error message received was %s" % (e)) 
200                  logger.log(["DB Schema upgrade failed"]) 
201                  logger.close() 
202                  utils.fubar("DB Schema upgrade failed") 
203              database_revision += 1 
204          logger.close() 
205   
206  ################################################################################ 
207   
208 -    def init(self): 
209          cnf = Config() 
210          arguments = [('h', "help", "Update-DB::Options::Help"), 
211                       ("y", "yes", "Update-DB::Options::Yes")] 
212          for i in ["help"]: 
213              key = "Update-DB::Options::%s" % i 
214              if key not in cnf: 
215                  cnf[key] = "" 
216   
217          arguments = apt_pkg.parse_commandline(cnf.Cnf, arguments, sys.argv) 
218   
219          options = cnf.subtree("Update-DB::Options") 
220          if options["Help"]: 
221              self.usage() 
222          elif arguments: 
223              utils.warn("dak update-db takes no arguments.") 
224              self.usage(exit_code=1) 
225   
226          try: 
227              if os.path.isdir(cnf["Dir::Lock"]): 
228                  lock_fd = os.open(os.path.join(cnf["Dir::Lock"], 'daily.lock'), os.O_RDONLY | os.O_CREAT) 
229                  fcntl.flock(lock_fd, fcntl.LOCK_EX | fcntl.LOCK_NB) 
230              else: 
231                  utils.warn("Lock directory doesn't exist yet - not locking") 
232          except OSError as e: 
233              if e.errno in (errno.EACCES, errno.EAGAIN): 
234                  utils.fubar("Couldn't obtain lock, looks like archive is doing something, try again later.") 
235              else: 
236                  raise 
237   
238          self.update_db() 
239   
240   
241  ################################################################################ 
242   
243  if __name__ == '__main__': 
244      app = UpdateDB() 
245      app.init() 
246   
247   
248 -def main(): 
249      app = UpdateDB() 
250      app.init() 
251