wizard/command/upgrade.py

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