wizard/command/upgrade.py

   1 import sys
   2 import distutils.version
   3 import os
   4 import shutil
   5 import logging.handlers
   6 import tempfile
   7 import itertools
   8 import time
   9 import errno
  10
  11 from wizard import app, command, deploy, scripts, shell, util
  12
  13 kib_buffer = 1024 * 30 # 30 MiB we will always leave available
  14 errno_blacklisted = 64
  15
  16 def main(argv, baton):
  17     options, args = parse_args(argv, baton)
  18     if args:
  19         dir = args[0]
  20     else:
  21         dir = "."
  22     shell.drop_priviledges(dir, options.log_file)
  23     util.set_git_env()
  24     upgrade = Upgrade(options)
  25     upgrade.execute(dir)
  26     if not options.non_interactive:
  27         print "Upgrade complete"
  28
  29 class Upgrade(object):
  30     """
  31     Represents the algorithm for upgrading an application.  This is in
  32     a class and not a function because it's a multi-step process that
  33     requires state betweens steps.  Steps are represented as methods
  34     in this object.
  35     """
  36
  37     #: Version of application we are upgrading to, i.e. the latest version.
  38     version = None # XXX: This is a string... I'm not convinced it should be
  39     #: String commit ID of the user's latest wc; i.e. "ours"
  40     user_commit = None
  41     #: String commit ID of the latest, greatest scripts version; i.e. "theirs"
  42     next_commit = None
  43     #: The temporary directory that the system gave us; may stay as ``None``
  44     #: if we don't ever make ourselves a temporary directory (e.g. ``--continue``).
  45     #: While we should clean this up if it is set to something, it may
  46     #: not correspond to anything useful.
  47     temp_dir = None
  48     #: The temporary directory containing our working copy for merging
  49     temp_wc_dir = None
  50     #: We place the temporary repositories inside a tmpfs while merging;
  51     #: this makes merges not disk-bound and affords a modest speed increase.
  52     #: If you are running ``--continue``, this is guaranteed to be ``False``.
  53     use_shm = None
  54     #: Upstream repository to use.  This does not need to be saved.
  55     repo = None
  56
  57     #: Instance of :class:`wizard.deploy.WorkingCopy` for this upgrade
  58     wc = None
  59     #: Instance of :class:`wizard.deploy.ProductionCopy` for this upgrade
  60     prod = None
  61
  62     #: Options object that the installer was called with
  63     options = None
  64
  65     def __init__(self, options):
  66         self.version = None
  67         self.user_commit = None
  68         self.next_commit = None
  69         self.temp_dir = None
  70         self.temp_wc_dir = None
  71         self.use_shm = False # False until proven otherwise.
  72         self.wc = None
  73         self.prod = None
  74         self.options = options
  75
  76     def execute(self, dir):
  77         """
  78         Executes an upgrade.  This is the entry-point.
  79         """
  80         with util.ChangeDirectory(dir):
  81             try:
  82                 if self.options.continue_:
  83                     logging.info("Continuing upgrade...")
  84                     self.resume()
  85                 else:
  86                     logging.info("Upgrading %s" % os.getcwd())
  87                     self.preflight()
  88                     self.merge()
  89                 self.postflight()
  90                 # Till now, all of our operations were in a tmp sandbox.
  91                 if self.options.dry_run:
  92                     logging.info("Dry run, bailing.  See results at %s" % self.temp_wc_dir)
  93                     return
  94                 backup = self.backup()
  95                 self.upgrade(backup)
  96             finally:
  97                 if self.use_shm and self.temp_dir and os.path.exists(self.temp_dir):
  98                     shutil.rmtree(self.temp_dir)
  99
 100     def resume(self):
 101         """
 102         In the event of a ``--continue`` flag, we have to restore state and
 103         perform some sanity checks.
 104         """
 105         self.resumeChdir()
 106         self.resumeState()
 107         self.resumeLogging()
 108         util.chdir(shell.eval("git", "config", "remote.origin.url"))
 109         self.resumeProd()
 110     def resumeChdir(self):
 111         """
 112         If we called ``--continue`` inside a production copy,  check if
 113         :file:`.scripts/pending` exists and change to that directory if so.
 114         """
 115         if os.path.exists(".scripts/pending"):
 116             newdir = open(".scripts/pending").read().strip()
 117             logging.warning("Detected production copy; changing directory to %s", newdir)
 118             os.chdir(newdir)
 119     def resumeState(self):
 120         self.temp_wc_dir = os.getcwd()
 121         self.wc = deploy.WorkingCopy(".")
 122         try:
 123             self.user_commit, self.next_commit = open(".git/WIZARD_PARENTS", "r").read().split()
 124             self.version = open(".git/WIZARD_UPGRADE_VERSION", "r").read()
 125         except IOError as e:
 126             if e.errno == errno.ENOENT:
 127                 raise CannotResumeError()
 128             else:
 129                 raise
 130     def resumeLogging(self):
 131         options = self.options
 132         if not options.log_file and os.path.exists(".git/WIZARD_LOG_FILE"):
 133             options.log_file = open(".git/WIZARD_LOG_FILE", "r").read()
 134             command.setup_file_logger(options.log_file, options.debug)
 135     def resumeProd(self):
 136         """Restore :attr:`prod` attribute, and check if the production copy has drifted."""
 137         self.prod = deploy.ProductionCopy(".")
 138         try:
 139             shell.call("git", "status")
 140             raise LocalChangesError()
 141         except shell.CallError:
 142             pass
 143
 144     def preflight(self):
 145         """
 146         Make sure that a number of pre-upgrade invariants are met before
 147         attempting anything.
 148         """
 149         options = self.options
 150         self.prod = deploy.ProductionCopy(".")
 151         self.repo = self.prod.application.repository(options.srv_path)
 152         # XXX: put this in Application
 153         self.version = shell.eval("git", "--git-dir="+self.repo, "describe", "--tags", "master")
 154         self.preflightBlacklist()
 155         self.prod.verify()
 156         self.prod.verifyTag(options.srv_path)
 157         self.prod.verifyGit(options.srv_path)
 158         self.prod.verifyConfigured()
 159         shell.call("git", "fetch", "--tags") # XXX: hack since some installs have stale tags
 160         self.prod.verifyVersion()
 161         self.prod.verifyWeb()
 162         self.preflightAlreadyUpgraded()
 163         self.preflightQuota()
 164     def preflightBlacklist(self):
 165         if os.path.exists(".scripts/blacklisted"):
 166             reason = open(".scripts/blacklisted").read()
 167             # ignore blank blacklisted files
 168             if reason:
 169                 print reason
 170                 raise BlacklistedError(reason)
 171             else:
 172                 logging.warning("Application was blacklisted, but no reason was found");
 173     def preflightAlreadyUpgraded(self):
 174         if self.version == self.prod.app_version.scripts_tag and not self.options.force:
 175             # don't log this error; we need to have the traceback line
 176             # so that the parsing code can catch it
 177             # XXX: maybe we should build this in as a flag to add
 178             # to exceptions w/ our exception handler
 179             sys.stderr.write("Traceback:\n  (n/a)\nAlreadyUpgraded\n")
 180             sys.exit(2)
 181     def preflightQuota(self):
 182         kib_usage, kib_limit = scripts.get_quota_usage_and_limit()
 183         if kib_limit is not None and (kib_limit - kib_usage) < kib_buffer:
 184             raise QuotaTooLow
 185
 186     def merge(self):
 187         if not self.options.dry_run:
 188             self.mergePreCommit()
 189         self.mergeClone()
 190         logging.debug("Temporary WC dir is %s", self.temp_wc_dir)
 191         with util.ChangeDirectory(self.temp_wc_dir):
 192             self.wc = deploy.WorkingCopy(".")
 193             shell.call("git", "remote", "add", "scripts", self.repo)
 194             shell.call("git", "fetch", "-q", "scripts")
 195             self.user_commit = shell.eval("git", "rev-parse", "HEAD")
 196             self.next_commit = shell.eval("git", "rev-parse", self.version)
 197             self.mergeSaveState()
 198             self.mergePerform()
 199     def mergePreCommit(self):
 200         message = "Pre-commit of %s locker before autoinstall upgrade.\n\n%s" % (util.get_dir_owner(), util.get_git_footer())
 201         try:
 202             message += "\nPre-commit-by: " + util.get_operator_git()
 203         except util.NoOperatorInfo:
 204             pass
 205         try:
 206             shell.call("git", "commit", "-a", "-m", message)
 207         except shell.CallError:
 208             logging.info("No changes detected")
 209     def mergeClone(self):
 210         # If /dev/shm exists, it's a tmpfs and we can use it
 211         # to do a fast git merge. Don't forget to move it to
 212         # /tmp if it fails.
 213         if not self.options.dry_run and not self.options.debug:
 214             self.use_shm = os.path.exists("/dev/shm")
 215         if self.use_shm:
 216             dir = "/dev/shm/wizard"
 217             if not os.path.exists(dir):
 218                 os.mkdir(dir)
 219                 # XXX: race
 220                 os.chmod(dir, 0o777)
 221         else:
 222             dir = None
 223         self.temp_dir = tempfile.mkdtemp(prefix="wizard", dir=dir)
 224         self.temp_wc_dir = os.path.join(self.temp_dir, "repo")
 225         logging.info("Using temporary directory: " + self.temp_wc_dir)
 226         shell.call("git", "clone", "-q", "--shared", ".", self.temp_wc_dir)
 227     def mergeSaveState(self):
 228         """Save variables so that ``--continue`` will work."""
 229         # yeah yeah no trailing newline whatever
 230         open(".git/WIZARD_UPGRADE_VERSION", "w").write(self.version)
 231         open(".git/WIZARD_PARENTS", "w").write("%s\n%s" % (self.user_commit, self.next_commit))
 232         open(".git/WIZARD_SIZE", "w").write(str(scripts.get_disk_usage()))
 233         if self.options.log_file:
 234             open(".git/WIZARD_LOG_FILE", "w").write(self.options.log_file)
 235     def mergePerform(self):
 236         def make_virtual_commit(rev, parents = []):
 237             """
 238             Takes a revision and generates a "virtual" commit with
 239             user-specific variables instantiated for a smooth, easy
 240             merge.
 241
 242             .. warning::
 243
 244                 Changes the state of the working copy.
 245             """
 246             shell.call("git", "checkout", "-q", rev, "--")
 247             self.wc.parametrize(self.prod)
 248             for file in self.wc.application.parametrized_files:
 249                 try:
 250                     shell.call("git", "add", "--", file)
 251                 except shell.CallError:
 252                     pass
 253             virtual_tree = shell.eval("git", "write-tree", log=True)
 254             parent_args = itertools.chain(*(["-p", p] for p in parents))
 255             virtual_commit = shell.eval("git", "commit-tree", virtual_tree,
 256                     *parent_args, input="", log=True)
 257             shell.call("git", "reset", "--hard")
 258             return virtual_commit
 259         user_tree = shell.eval("git", "rev-parse", "HEAD^{tree}")
 260         base_virtual_commit = make_virtual_commit(self.wc.app_version.scripts_tag)
 261         next_virtual_commit = make_virtual_commit(self.version, [base_virtual_commit])
 262         user_virtual_commit = shell.eval("git", "commit-tree", user_tree,
 263                 "-p", base_virtual_commit, input="", log=True)
 264         shell.call("git", "checkout", user_virtual_commit, "--")
 265         self.wc.prepareMerge()
 266         try:
 267             shell.call("git", "commit", "--amend", "-a", "-m", "amendment")
 268         except shell.CallError as e:
 269             pass
 270         shell.call("git", "config", "merge.conflictstyle", "diff3")
 271         try:
 272             shell.call("git", "merge", next_virtual_commit)
 273         except shell.CallError as e:
 274             logging.info("Merge failed with these messages:\n\n" + e.stderr)
 275             # Run the application's specific merge resolution algorithms
 276             # and see if we can salvage it
 277             if self.wc.resolveConflicts():
 278                 logging.info("Resolved conflicts with application specific knowledge")
 279                 shell.call("git", "commit", "-a", "-m", "merge")
 280                 return
 281             files = set()
 282             for line in shell.eval("git", "ls-files", "--unmerged").splitlines():
 283                 files.add(line.split(None, 3)[-1])
 284             conflicts = len(files)
 285             # XXX: this is kind of fiddly; note that temp_dir still points at the OLD
 286             # location after this code.
 287             self.temp_wc_dir = mv_shm_to_tmp(os.getcwd(), self.use_shm)
 288             self.wc.location = self.temp_wc_dir
 289             os.chdir(self.temp_wc_dir)
 290             open(os.path.join(self.prod.location, ".scripts/pending"), "w").write(self.temp_wc_dir)
 291             if self.options.non_interactive:
 292                 print "%d %s" % (conflicts, self.temp_wc_dir)
 293                 raise MergeFailed
 294             else:
 295                 user_shell = os.getenv("SHELL")
 296                 if not user_shell: user_shell = "/bin/bash"
 297                 # XXX: scripts specific hack, since mbash doesn't respect the current working directory
 298                 # When the revolution comes (i.e. $ATHENA_HOMEDIR/Scripts is your Scripts home
 299                 # directory) this isn't strictly necessary, but we'll probably need to support
 300                 # web_scripts directories ad infinitum.
 301                 if user_shell == "/usr/local/bin/mbash": user_shell = "/bin/bash"
 302                 while 1:
 303                     print
 304                     print "ERROR: The merge failed with %d conflicts in these files:" % conflicts
 305                     print
 306                     for file in sorted(files):
 307                         print "  * %s" % file
 308                     print
 309                     print "Please resolve these conflicts (edit and then `git add`), and"
 310                     print "then type 'exit'.  You will now be dropped into a shell whose working"
 311                     print "directory is %s" % self.temp_wc_dir
 312                     try:
 313                         shell.call(user_shell, "-i", interactive=True)
 314                     except shell.CallError as e:
 315                         logging.warning("Shell returned non-zero exit code %d" % e.code)
 316                     if shell.eval("git", "ls-files", "--unmerged").strip():
 317                         print
 318                         print "WARNING: There are still unmerged files."
 319                         out = raw_input("Continue editing? [y/N]: ")
 320                         if out == "y" or out == "Y":
 321                             continue
 322                         else:
 323                             print "Aborting.  The conflicted working copy can be found at:"
 324                             print
 325                             print "    %s" % self.temp_wc_dir
 326                             print
 327                             print "and you can resume the upgrade process by running in that directory:"
 328                             print
 329                             print "    wizard upgrade --continue"
 330                             sys.exit(1)
 331                     break
 332
 333     def postflight(self):
 334         with util.ChangeDirectory(self.temp_wc_dir):
 335             try:
 336                 shell.call("git", "status")
 337             except shell.CallError:
 338                 pass
 339             else:
 340                 shell.call("git", "commit", "--allow-empty", "-am", "throw-away commit")
 341             message = self.postflightCommitMessage()
 342             new_tree = shell.eval("git", "rev-parse", "HEAD^{tree}")
 343             final_commit = shell.eval("git", "commit-tree", new_tree,
 344                     "-p", self.user_commit, "-p", self.next_commit, input=message, log=True)
 345             # a master branch may not necessarily exist if the user
 346             # was manually installed to an earlier version
 347             try:
 348                 shell.call("git", "checkout", "-q", "-b", "master", "--")
 349             except shell.CallError:
 350                 shell.call("git", "checkout", "-q", "master", "--")
 351             shell.call("git", "reset", "-q", "--hard", final_commit)
 352             # This is a quick sanity check to make sure we didn't completely
 353             # mess up the merge
 354             self.wc.invalidateCache()
 355             self.wc.verifyVersion()
 356     def postflightCommitMessage(self):
 357         message = "Upgraded autoinstall in %s to %s.\n\n%s" % (util.get_dir_owner(), self.version, util.get_git_footer())
 358         try:
 359             message += "\nUpgraded-by: " + util.get_operator_git()
 360         except util.NoOperatorInfo:
 361             pass
 362         return message
 363
 364     def backup(self):
 365         # Ok, now we have to do a crazy complicated dance to see if we're
 366         # going to have enough quota to finish what we need
 367         pre_size = int(open(os.path.join(self.temp_wc_dir, ".git/WIZARD_SIZE"), "r").read())
 368         post_size = scripts.get_disk_usage(self.temp_wc_dir)
 369         backup = self.prod.backup(self.options)
 370         kib_usage, kib_limit = scripts.get_quota_usage_and_limit()
 371         if kib_limit is not None and (kib_limit - kib_usage) - (post_size - pre_size) / 1024 < kib_buffer:
 372             shutil.rmtree(os.path.join(".scripts/backups", shell.eval("wizard", "restore").splitlines()[0]))
 373             raise QuotaTooLow
 374         return backup
 375
 376     def upgrade(self, backup):
 377         # XXX: frob .htaccess to make site inaccessible
 378         with util.IgnoreKeyboardInterrupts():
 379             with util.LockDirectory(".scripts-upgrade-lock"):
 380                 shell.call("git", "fetch", "--tags")
 381                 # git merge (which performs a fast forward)
 382                 shell.call("git", "pull", "-q", self.temp_wc_dir, "master")
 383                 version_obj = distutils.version.LooseVersion(self.version.partition('-')[2])
 384                 try:
 385                     # run update script
 386                     self.prod.upgrade(version_obj, self.options)
 387                     self.prod.verifyWeb()
 388                 except app.UpgradeFailure:
 389                     logging.warning("Upgrade failed: rolling back")
 390                     self.upgradeRollback(backup)
 391                     raise
 392                 except deploy.WebVerificationError as e:
 393                     logging.warning("Web verification failed: rolling back")
 394                     self.upgradeRollback(backup)
 395                     raise app.UpgradeVerificationFailure()
 396         # XXX: frob .htaccess to make site accessible
 397         #       to do this, check if .htaccess changed, first.  Upgrade
 398         #       process might have frobbed it.  Don't be
 399         #       particularly worried if the segment disappeared
 400     def upgradeRollback(self, backup):
 401         # You don't want d.restore() because it doesn't perform
 402         # the file level backup
 403         shell.call("wizard", "restore", backup)
 404         try:
 405             self.prod.verifyWeb()
 406         except deploy.WebVerificationError:
 407             logging.critical("Web verification failed after rollback")
 408
 409 # utility functions
 410
 411 def mv_shm_to_tmp(curdir, use_shm):
 412     if not use_shm: return curdir
 413     # Keeping all of our autoinstalls in shared memory is
 414     # a recipe for disaster, so let's move them to slightly
 415     # less volatile storage (a temporary directory)
 416     os.chdir(tempfile.gettempdir())
 417     newdir = tempfile.mkdtemp(prefix="wizard")
 418     # shutil, not os; at least on Ubuntu os.move fails
 419     # with "[Errno 18] Invalid cross-device link"
 420     shutil.move(curdir, newdir)
 421     shutil.rmtree(os.path.dirname(curdir))
 422     curdir = os.path.join(newdir, "repo")
 423     return curdir
 424
 425 def parse_args(argv, baton):
 426     usage = """usage: %prog upgrade [ARGS] [DIR]
 427
 428 Upgrades an autoinstall to the latest version.  This involves
 429 updating files and running .scripts/update.  If the merge fails,
 430 this program will write the number of conflicts and the directory
 431 of the conflicted working tree to stdout, separated by a space."""
 432     parser = command.WizardOptionParser(usage)
 433     parser.add_option("--dry-run", dest="dry_run", action="store_true",
 434             default=False, help="Prints would would be run without changing anything")
 435     # notice trailing underscore
 436     parser.add_option("--continue", dest="continue_", action="store_true",
 437             default=False, help="Continues an upgrade that has had its merge manually "
 438             "resolved using the current working directory as the resolved copy.")
 439     parser.add_option("--force", dest="force", action="store_true",
 440             default=False, help="Force running upgrade even if it's already at latest version.")
 441     parser.add_option("--non-interactive", dest="non_interactive", action="store_true",
 442             default=False, help="Don't drop to shell in event of conflict.")
 443     baton.push(parser, "srv_path")
 444     options, args = parser.parse_all(argv)
 445     if len(args) > 1:
 446         parser.error("too many arguments")
 447     return options, args
 448
 449 class Error(command.Error):
 450     """Base exception for all exceptions raised by upgrade"""
 451     pass
 452
 453 class QuotaTooLow(Error):
 454     def __str__(self):
 455         return """
 456
 457 ERROR: The locker quota was too low to complete the autoinstall
 458 upgrade.
 459 """
 460
 461 class AlreadyUpgraded(Error):
 462     quiet = True
 463     def __str__(self):
 464         return """
 465
 466 ERROR: This autoinstall is already at the latest version."""
 467
 468 class MergeFailed(Error):
 469     quiet = True
 470     def __str__(self):
 471         return """
 472
 473 ERROR: Merge failed.  Above is the temporary directory that
 474 the conflicted merge is in: resolve the merge by cd'ing to the
 475 temporary directory, finding conflicted files with `git status`,
 476 resolving the files, adding them using `git add` and then
 477 running `wizard upgrade --continue`."""
 478
 479 class LocalChangesError(Error):
 480     def __str__(self):
 481         return """
 482
 483 ERROR: Local changes occurred in the install while the merge was
 484 being processed so that a pull would not result in a fast-forward.
 485 The best way to resolve this is probably to attempt an upgrade again,
 486 with git rerere to remember merge resolutions (XXX: not sure if
 487 this actually works)."""
 488
 489 class BlacklistedError(Error):
 490     #: Reason why the autoinstall was blacklisted
 491     reason = None
 492     exitcode = errno_blacklisted
 493     def __init__(self, reason):
 494         self.reason = reason
 495     def __str__(self):
 496         return """
 497
 498 ERROR: This autoinstall was manually blacklisted against errors;
 499 if the user has not been notified of this, please send them
 500 mail.
 501
 502 The reason was: %s""" % self.reason
 503
 504 class CannotResumeError(Error):
 505     def __str__(self):
 506         return """
 507
 508 ERROR: We cannot resume the upgrade process; either this working
 509 copy is missing essential metadata, or you've attempt to continue
 510 from a production copy that does not have any pending upgrades.
 511 """