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
   9 from wizard import app, command, deploy, scripts, shell, util
  10
  11 kib_buffer = 1024 * 30 # 30 MiB we will always leave available
  12 errno_blacklisted = 64
  13
  14 def main(argv, baton):
  15     options, args = parse_args(argv, baton)
  16     if args:
  17         dir = args[0]
  18     else:
  19         dir = "."
  20     shell.drop_priviledges(dir, options.log_file)
  21     util.chdir(dir)
  22     sh = shell.Shell()
  23     util.set_git_env()
  24     use_shm = False # if you are running --continue, this is guaranteed to be False
  25     temp_dir = None
  26     try: # global try-finally for cleaning up /dev/shm if it's being used
  27         if options.continue_:
  28             temp_wc_dir = os.getcwd()
  29             wc = deploy.WorkingCopy(".")
  30             user_commit, next_commit = open(".git/WIZARD_PARENTS", "r").read().split()
  31             repo = open(".git/WIZARD_REPO", "r").read()
  32             version = open(".git/WIZARD_UPGRADE_VERSION", "r").read()
  33             if not options.log_file and os.path.exists(".git/WIZARD_LOG_FILE"):
  34                 options.log_file = open(".git/WIZARD_LOG_FILE", "r").read()
  35                 # reload logging
  36                 command.setup_file_logger(options.log_file, options.debug)
  37             logging.info("Continuing upgrade...")
  38             util.chdir(sh.eval("git", "config", "remote.origin.url"))
  39             d = deploy.ProductionCopy(".")
  40             try:
  41                 sh.call("git", "status")
  42                 raise LocalChangesError()
  43             except shell.CallError:
  44                 pass
  45         else:
  46             d = deploy.ProductionCopy(".")
  47             if os.path.exists(".scripts/blacklisted"):
  48                 reason = open(".scripts/blacklisted").read()
  49                 print reason
  50                 raise BlacklistedError(reason)
  51             d.verify()
  52             d.verifyTag(options.srv_path)
  53             d.verifyGit(options.srv_path)
  54             d.verifyConfigured()
  55             d.verifyVersion()
  56             if not options.dry_run:
  57                 d.verifyWeb()
  58             repo = d.application.repository(options.srv_path)
  59             version = calculate_newest_version(sh, repo)
  60             if version == d.app_version.scripts_tag and not options.force:
  61                 # don't log this error
  62                 # XXX: maybe we should build this in as a flag to add
  63                 # to exceptions w/ our exception handler
  64                 sys.stderr.write("Traceback:\n  (n/a)\nAlreadyUpgraded\n")
  65                 sys.exit(1)
  66             logging.info("Upgrading %s" % os.getcwd())
  67             kib_usage, kib_limit = scripts.get_quota_usage_and_limit()
  68             if kib_limit is not None and (kib_limit - kib_usage) < kib_buffer:
  69                 raise QuotaTooLow
  70             if not options.dry_run:
  71                 perform_pre_commit(sh)
  72             # If /dev/shm exists, it's a tmpfs and we can use it
  73             # to do a fast git merge. Don't forget to move it to
  74             # /tmp if it fails.
  75             if not options.dry_run:
  76                 use_shm = os.path.exists("/dev/shm")
  77             temp_dir, temp_wc_dir = perform_tmp_clone(sh, use_shm)
  78             with util.ChangeDirectory(temp_wc_dir):
  79                 wc = deploy.WorkingCopy(".")
  80                 sh.call("git", "remote", "add", "scripts", repo)
  81                 sh.call("git", "fetch", "-q", "scripts")
  82                 user_commit, next_commit = calculate_parents(sh, version)
  83                 # save variables so that --continue will work
  84                 # yeah yeah no trailing newline whatever
  85                 open(".git/WIZARD_REPO", "w").write(repo)
  86                 open(".git/WIZARD_UPGRADE_VERSION", "w").write(version)
  87                 open(".git/WIZARD_PARENTS", "w").write("%s\n%s" % (user_commit, next_commit))
  88                 open(".git/WIZARD_SIZE", "w").write(str(scripts.get_disk_usage()))
  89                 if options.log_file:
  90                     open(".git/WIZARD_LOG_FILE", "w").write(options.log_file)
  91                 perform_merge(sh, repo, d, wc, version, use_shm, kib_limit and kib_limit - kib_usage or None)
  92         # variables: version, user_commit, next_commit, temp_wc_dir
  93         with util.ChangeDirectory(temp_wc_dir):
  94             try:
  95                 sh.call("git", "status")
  96                 sh.call("git", "commit", "-m", "throw-away commit")
  97             except shell.CallError:
  98                 pass
  99             message = make_commit_message(version)
 100             new_tree = sh.eval("git", "rev-parse", "HEAD^{tree}")
 101             final_commit = sh.eval("git", "commit-tree", new_tree,
 102                     "-p", user_commit, "-p", next_commit, input=message, log=True)
 103             # a master branch may not necessarily exist if the user
 104             # was manually installed to an earlier version
 105             try:
 106                 sh.call("git", "checkout", "-q", "-b", "master", "--")
 107             except shell.CallError:
 108                 sh.call("git", "checkout", "-q", "master", "--")
 109             sh.call("git", "reset", "-q", "--hard", final_commit)
 110             # This is a quick sanity check to make sure we didn't completely
 111             # mess up the merge
 112             wc.invalidateCache()
 113             wc.verifyVersion()
 114         # Till now, all of our operations were in a tmp sandbox.
 115         if options.dry_run:
 116             logging.info("Dry run, bailing.  See results at %s" % temp_wc_dir)
 117             return
 118         # Ok, now we have to do a crazy complicated dance to see if we're
 119         # going to have enough quota to finish what we need
 120         pre_size = int(open(os.path.join(temp_wc_dir, ".git/WIZARD_SIZE"), "r").read())
 121         post_size = scripts.get_disk_usage(temp_wc_dir)
 122         kib_usage, kib_limit = scripts.get_quota_usage_and_limit()
 123         backup = d.backup(options)
 124         if kib_limit is not None and (kib_limit - kib_usage) - (post_size - pre_size) / 1024 < kib_buffer:
 125             shutil.rmtree(os.path.join(".scripts/backups", sh.eval("wizard", "restore").splitlines()[0]))
 126             raise QuotaTooLow
 127         # XXX: frob .htaccess to make site inaccessible
 128         with util.IgnoreKeyboardInterrupts():
 129             with util.LockDirectory(".scripts-upgrade-lock"):
 130                 # git merge (which performs a fast forward)
 131                 sh.call("git", "pull", "-q", temp_wc_dir, "master")
 132                 version_obj = distutils.version.LooseVersion(version.partition('-')[2])
 133                 try:
 134                     # run update script
 135                     d.upgrade(version_obj, options)
 136                     d.verifyWeb()
 137                 except app.UpgradeFailure:
 138                     logging.warning("Upgrade failed: rolling back")
 139                     perform_restore(d, backup)
 140                     raise
 141                 except deploy.WebVerificationError as e:
 142                     logging.warning("Web verification failed: rolling back")
 143                     perform_restore(d, backup)
 144                     raise app.UpgradeVerificationFailure(e.contents)
 145         # XXX: frob .htaccess to make site accessible
 146         #       to do this, check if .htaccess changed, first.  Upgrade
 147         #       process might have frobbed it.  Don't be
 148         #       particularly worried if the segment disappeared
 149     finally:
 150         if use_shm and temp_dir and os.path.exists(temp_dir):
 151             shutil.rmtree(temp_dir)
 152
 153 def perform_restore(d, backup):
 154     # You don't want d.restore() because it doesn't perform
 155     # the file level backup
 156     shell.Shell().call("wizard", "restore", backup)
 157     try:
 158         d.verifyWeb()
 159     except deploy.WebVerificationError:
 160         logging.critical("Web verification failed after rollback")
 161
 162 def make_commit_message(version):
 163     message = "Upgraded autoinstall in %s to %s.\n\n%s" % (util.get_dir_owner(), version, util.get_git_footer())
 164     try:
 165         message += "\nUpgraded-by: " + util.get_operator_git()
 166     except util.NoOperatorInfo:
 167         pass
 168     return message
 169
 170 def calculate_newest_version(sh, repo):
 171     # XXX: put this in Application
 172     return sh.eval("git", "--git-dir="+repo, "describe", "--tags", "master")
 173
 174 def calculate_parents(sh, version):
 175     user_commit = sh.eval("git", "rev-parse", "HEAD")
 176     next_commit = sh.eval("git", "rev-parse", version)
 177     return user_commit, next_commit
 178
 179 def perform_pre_commit(sh):
 180     message = "Pre-commit of %s locker before autoinstall upgrade.\n\n%s" % (util.get_dir_owner(), util.get_git_footer())
 181     try:
 182         message += "\nPre-commit-by: " + util.get_operator_git()
 183     except util.NoOperatorInfo:
 184         pass
 185     try:
 186         sh.call("git", "commit", "-a", "-m", message)
 187     except shell.CallError:
 188         logging.info("No changes detected")
 189
 190 def perform_tmp_clone(sh, use_shm):
 191     if use_shm:
 192         dir = "/dev/shm/wizard"
 193         if not os.path.exists(dir):
 194             os.mkdir(dir)
 195             os.chmod(dir, 0o777)
 196     else:
 197         dir = None
 198     temp_dir = tempfile.mkdtemp(prefix="wizard", dir=dir)
 199     temp_wc_dir = os.path.join(temp_dir, "repo")
 200     logging.info("Using temporary directory: " + temp_wc_dir)
 201     sh.call("git", "clone", "-q", "--shared", ".", temp_wc_dir)
 202     return temp_dir, temp_wc_dir
 203
 204 def perform_merge(sh, repo, d, wc, version, use_shm, kib_avail):
 205     # Note: avail_quota == None means unlimited
 206     # naive merge algorithm:
 207     # sh.call("git", "merge", "-m", message, "scripts/master")
 208     # crazy merge algorithm:
 209     def make_virtual_commit(tag, parents = []):
 210         """WARNING: Changes state of Git repository"""
 211         sh.call("git", "checkout", "-q", tag, "--")
 212         wc.parametrize(d)
 213         for file in wc.application.parametrized_files:
 214             try:
 215                 sh.call("git", "add", "--", file)
 216             except shell.CallError:
 217                 pass
 218         virtual_tree = sh.eval("git", "write-tree", log=True)
 219         parent_args = itertools.chain(*(["-p", p] for p in parents))
 220         virtual_commit = sh.eval("git", "commit-tree", virtual_tree,
 221                 *parent_args, input="", log=True)
 222         sh.call("git", "reset", "--hard")
 223         return virtual_commit
 224     user_tree = sh.eval("git", "rev-parse", "HEAD^{tree}")
 225     base_virtual_commit = make_virtual_commit(wc.app_version.scripts_tag)
 226     next_virtual_commit = make_virtual_commit(version, [base_virtual_commit])
 227     user_virtual_commit = sh.eval("git", "commit-tree", user_tree,
 228             "-p", base_virtual_commit, input="", log=True)
 229     sh.call("git", "checkout", user_virtual_commit, "--")
 230     wc.prepareMerge()
 231     sh.call("git", "commit", "--amend", "-a", "-m", "amendment")
 232     try:
 233         sh.call("git", "merge", next_virtual_commit)
 234     except shell.CallError as e:
 235         conflicts = e.stdout.count("CONFLICT") # not perfect, if there is a file named CONFLICT
 236         logging.info("Merge failed with these messages:\n\n" + e.stderr)
 237         # Run the application's specific merge resolution algorithms
 238         # and see if we can salvage it
 239         curdir = os.getcwd()
 240         if wc.resolveConflicts():
 241             logging.info("Resolved conflicts with application specific knowledge")
 242             sh.call("git", "commit", "-a", "-m", "merge")
 243             return
 244         # XXX: Maybe should recalculate conflicts
 245         logging.info("Conflict info:\n" + sh.eval("git", "diff"))
 246         curdir = mv_shm_to_tmp(curdir, use_shm)
 247         print "%d %s" % (conflicts, curdir)
 248         raise MergeFailed
 249
 250 def mv_shm_to_tmp(curdir, use_shm):
 251     if not use_shm: return curdir
 252     # Keeping all of our autoinstalls in shared memory is
 253     # a recipe for disaster, so let's move them to slightly
 254     # less volatile storage (a temporary directory)
 255     os.chdir(tempfile.gettempdir())
 256     newdir = tempfile.mkdtemp(prefix="wizard")
 257     # shutil, not os; at least on Ubuntu os.move fails
 258     # with "[Errno 18] Invalid cross-device link"
 259     shutil.move(curdir, newdir)
 260     shutil.rmtree(os.path.dirname(curdir))
 261     curdir = os.path.join(newdir, "repo")
 262     return curdir
 263
 264 def parse_args(argv, baton):
 265     usage = """usage: %prog upgrade [ARGS] [DIR]
 266
 267 Upgrades an autoinstall to the latest version.  This involves
 268 updating files and running .scripts/update.  If the merge fails,
 269 this program will write the number of conflicts and the directory
 270 of the conflicted working tree to stdout, separated by a space."""
 271     parser = command.WizardOptionParser(usage)
 272     parser.add_option("--dry-run", dest="dry_run", action="store_true",
 273             default=False, help="Prints would would be run without changing anything")
 274     # notice trailing underscore
 275     parser.add_option("--continue", dest="continue_", action="store_true",
 276             default=False, help="Continues an upgrade that has had its merge manually "
 277             "resolved using the current working directory as the resolved copy.")
 278     parser.add_option("--force", dest="force", action="store_true",
 279             default=False, help="Force running upgrade even if it's already at latest version.")
 280     baton.push(parser, "srv_path")
 281     options, args = parser.parse_all(argv)
 282     if len(args) > 1:
 283         parser.error("too many arguments")
 284     return options, args
 285
 286 class Error(command.Error):
 287     """Base exception for all exceptions raised by upgrade"""
 288     pass
 289
 290 class QuotaTooLow(Error):
 291     def __str__(self):
 292         return """
 293
 294 ERROR: The locker quota was too low to complete the autoinstall
 295 upgrade.
 296 """
 297
 298 class AlreadyUpgraded(Error):
 299     def __str__(self):
 300         return """
 301
 302 ERROR: This autoinstall is already at the latest version."""
 303
 304 class MergeFailed(Error):
 305     def __str__(self):
 306         return """
 307
 308 ERROR: Merge failed.  Resolve the merge by cd'ing to the
 309 temporary directory, finding conflicted files with `git status`,
 310 resolving the files, adding them using `git add` and then
 311 running `wizard upgrade --continue`."""
 312
 313 class LocalChangesError(Error):
 314     def __str__(self):
 315         return """
 316
 317 ERROR: Local changes occurred in the install while the merge was
 318 being processed so that a pull would not result in a fast-forward.
 319 The best way to resolve this is probably to attempt an upgrade again,
 320 with git rerere to remember merge resolutions (XXX: not sure if
 321 this actually works)."""
 322
 323 class BlacklistedError(Error):
 324     #: Reason why the autoinstall was blacklisted
 325     reason = None
 326     exitcode = errno_blacklisted
 327     def __init__(self, reason):
 328         self.reason = reason
 329     def __str__(self):
 330         return """
 331
 332 ERROR: This autoinstall was manually blacklisted against errors;
 333 if the user has not been notified of this, please send them
 334 mail.
 335
 336 The reason was: %s""" % self.reason