SVN pre-commit hook for avoiding changes to tags subdirectories

I don't have enough reputation to "comment" on Raim's answer above, but his worked great, with one exception, his grep pattern is wrong.

I simply used the below as my pre-commit hook (I didn't have an existing one, you'd need to merge in that case):

#!/bin/sh

REPOS="$1"
TXN="$2"

SVNLOOK=/opt/local/bin/svnlook

# Committing to tags is not allowed
$SVNLOOK changed -t "$TXN" "$REPOS" | grep "^U\W.*\/tags\/" && /bin/echo "Cannot commit to tags!" 1>&2 && exit 1

# All checks passed, so allow the commit.
exit 0

The only problem with Raim's grep pattern is that it only matched "tags" if it was at the "root" of your repo. Since I have several projects in my repo, the script as he wrote it allowed commits on tag branches.

Also, be sure to chmod +x as indicated, otherwise you'll think it worked b/c the commit failed, but it failed b/c it couldn't exec the pre-commit hook, not because the hook worked.

This was really great, thanks Raim. Much better and lighter weight than all other suggestions as it has no dependencies!

Here is a short shell script to prevent committing to tags after they have been created:

#!/bin/sh

REPOS="$1"
TXN="$2"

SVNLOOK=/usr/bin/svnlook

# Committing to tags is not allowed
$SVNLOOK changed -t "$TXN" "$REPOS" | grep "^U\W*tags" && /bin/echo "Cannot commit to tags!" 1>&2 && exit 1

# All checks passed, so allow the commit.
exit 0

Save this at hooks/pre-commit for your Subversion repository and make it executable with chmod +x.

Pretty late to the party, however I wrote a python pre-commit hook for work which is based off the log-police.py script on http://subversion.tigris.org/.

This script should do what you want, however it also checks that a log message exists, though that should be easy to remove from the script.

Some caveats:

• I'm new to Python, so it most likely could be written better
• It has only been tested on Windows 2003 with Python 2.5 and Subversion 1.4.

Requirements:

• Subversion
• Python
• Subversion bindings for Python

Finally, the code:

#!/usr/bin/env python

#
# pre-commit.py:
#
# Performs the following:
#  - Makes sure the author has entered in a log message.
#  - Make sure author is only creating a tag, or if deleting a tag, author is a specific user
#
# Script based on http://svn.collab.net/repos/svn/trunk/tools/hook-scripts/log-police.py
#
# usage: pre-commit.py -t TXN_NAME REPOS
# E.g. in pre-commit.bat (under Windows)
#   python.exe {common_hooks_dir}\pre_commit.py -t %2 %1
#


import os
import sys
import getopt
try:
  my_getopt = getopt.gnu_getopt
except AttributeError:
  my_getopt = getopt.getopt

import re

import svn
import svn.fs
import svn.repos
import svn.core

#
# Check Tags functionality
#
def check_for_tags(txn):
  txn_root = svn.fs.svn_fs_txn_root(txn)
  changed_paths = svn.fs.paths_changed(txn_root)
  for path, change in changed_paths.iteritems():
    if is_path_within_a_tag(path): # else go to next path
      if is_path_a_tag(path):
        if (change.change_kind == svn.fs.path_change_delete):
          if not is_txn_author_allowed_to_delete(txn):
            sys.stderr.write("\nOnly an administrator can delete a tag.\n\nContact your Subversion Administrator for details.")
            return False
        elif (change.change_kind != svn.fs.path_change_add):
          sys.stderr.write("\nUnable to modify " + path + ".\n\nIt is within a tag and tags are read-only.\n\nContact your Subversion Administrator for details.")
          return False
        # else user is adding a tag, so accept this change
      else:
        sys.stderr.write("\nUnable to modify " + path + ".\n\nIt is within a tag and tags are read-only.\n\nContact your Subversion Administrator for details.")
        return False
  return True

def is_path_within_a_tag(path):
  return re.search('(?i)\/tags\/', path)

def is_path_a_tag(path):
  return re.search('(?i)\/tags\/[^\/]+\/?$', path)

def is_txn_author_allowed_to_delete(txn):
  author = get_txn_property(txn, 'svn:author')
  return (author == 'bob.smith')

#
# Check log message functionality
#
def check_log_message(txn):
  log_message = get_txn_property(txn, "svn:log")
  if log_message is None or log_message.strip() == "":
    sys.stderr.write("\nCannot enter in empty commit message.\n")
    return False
  else:
    return True

def get_txn_property(txn, prop_name):
  return svn.fs.svn_fs_txn_prop(txn, prop_name)

def usage_and_exit(error_msg=None):
  import os.path
  stream = error_msg and sys.stderr or sys.stdout
  if error_msg:
    stream.write("ERROR: %s\n\n" % error_msg)
  stream.write("USAGE: %s -t TXN_NAME REPOS\n"
               % (os.path.basename(sys.argv[0])))
  sys.exit(error_msg and 1 or 0)

def main(ignored_pool, argv):
  repos_path = None
  txn_name = None

  try:
    opts, args = my_getopt(argv[1:], 't:h?', ["help"])
  except:
    usage_and_exit("problem processing arguments / options.")
  for opt, value in opts:
    if opt == '--help' or opt == '-h' or opt == '-?':
      usage_and_exit()
    elif opt == '-t':
      txn_name = value
    else:
      usage_and_exit("unknown option '%s'." % opt)

  if txn_name is None:
    usage_and_exit("must provide -t argument")
  if len(args) != 1:
    usage_and_exit("only one argument allowed (the repository).")

  repos_path = svn.core.svn_path_canonicalize(args[0])

  fs = svn.repos.svn_repos_fs(svn.repos.svn_repos_open(repos_path))
  txn = svn.fs.svn_fs_open_txn(fs, txn_name)

  if check_log_message(txn) and check_for_tags(txn):
    sys.exit(0)
  else:
    sys.exit(1)

if __name__ == '__main__':
  sys.exit(svn.core.run_app(main, sys.argv))

My version only allows creating and deleting tags. This should handle all the special cases (like adding files, changing properties, etc.).

#!/bin/sh

REPOS="$1"
TXN="$2"
SVNLOOK=/usr/local/bin/svnlook

output_error_and_exit() {
    echo "$1" >&2
    exit 1
}

changed_tags=$( $SVNLOOK changed -t "$TXN" "$REPOS" | grep "[ /]tags/." )

if [ "$changed_tags" ]
then 
    echo "$changed_tags" | egrep -v "^[AD] +(.*/)?tags/[^/]+/$" && output_error_and_exit "Modification of tags is not allowed."
fi 

exit 0