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