mirror of
https://github.com/git/git
synced 2024-08-27 19:49:21 +00:00
![Junio C Hamano](/assets/img/avatar_default.png)
The branch policy script I outlined was improved and polished by Carl and posted on the list twice since then. It is a shame not to pick it up, so replace the original outline in howto/update-hook-example.txt with the latest from Carl. Also talk about setting up git-shell to allow git-push/git-fetch only SSH access to a shared repository host in the tutorial. Signed-off-by: Junio C Hamano <junkio@cox.net>
173 lines
5.5 KiB
Plaintext
173 lines
5.5 KiB
Plaintext
From: Junio C Hamano <junkio@cox.net> and Carl Baldwin <cnb@fc.hp.com>
|
|
Subject: control access to branches.
|
|
Date: Thu, 17 Nov 2005 23:55:32 -0800
|
|
Message-ID: <7vfypumlu3.fsf@assigned-by-dhcp.cox.net>
|
|
Abstract: An example hooks/update script is presented to
|
|
implement repository maintenance policies, such as who can push
|
|
into which branch and who can make a tag.
|
|
|
|
When your developer runs git-push into the repository,
|
|
git-receive-pack is run (either locally or over ssh) as that
|
|
developer, so is hooks/update script. Quoting from the relevant
|
|
section of the documentation:
|
|
|
|
Before each ref is updated, if $GIT_DIR/hooks/update file exists
|
|
and executable, it is called with three parameters:
|
|
|
|
$GIT_DIR/hooks/update refname sha1-old sha1-new
|
|
|
|
The refname parameter is relative to $GIT_DIR; e.g. for the
|
|
master head this is "refs/heads/master". Two sha1 are the
|
|
object names for the refname before and after the update. Note
|
|
that the hook is called before the refname is updated, so either
|
|
sha1-old is 0{40} (meaning there is no such ref yet), or it
|
|
should match what is recorded in refname.
|
|
|
|
So if your policy is (1) always require fast-forward push
|
|
(i.e. never allow "git-push repo +branch:branch"), (2) you
|
|
have a list of users allowed to update each branch, and (3) you
|
|
do not let tags to be overwritten, then you can use something
|
|
like this as your hooks/update script.
|
|
|
|
[jc: editorial note. This is a much improved version by Carl
|
|
since I posted the original outline]
|
|
|
|
-- >8 -- beginning of script -- >8 --
|
|
|
|
#!/bin/bash
|
|
|
|
umask 002
|
|
|
|
# If you are having trouble with this access control hook script
|
|
# you can try setting this to true. It will tell you exactly
|
|
# why a user is being allowed/denied access.
|
|
|
|
verbose=false
|
|
|
|
# Default shell globbing messes things up downstream
|
|
GLOBIGNORE=*
|
|
|
|
function grant {
|
|
$verbose && echo >&2 "-Grant- $1"
|
|
echo grant
|
|
exit 0
|
|
}
|
|
|
|
function deny {
|
|
$verbose && echo >&2 "-Deny- $1"
|
|
echo deny
|
|
exit 1
|
|
}
|
|
|
|
function info {
|
|
$verbose && echo >&2 "-Info- $1"
|
|
}
|
|
|
|
# Implement generic branch and tag policies.
|
|
# - Tags should not be updated once created.
|
|
# - Branches should only be fast-forwarded.
|
|
case "$1" in
|
|
refs/tags/*)
|
|
[ -f "$GIT_DIR/$1" ] &&
|
|
deny >/dev/null "You can't overwrite an existing tag"
|
|
;;
|
|
refs/heads/*)
|
|
# No rebasing or rewinding
|
|
if expr "$2" : '0*$' >/dev/null; then
|
|
info "The branch '$1' is new..."
|
|
else
|
|
# updating -- make sure it is a fast forward
|
|
mb=$(git-merge-base "$2" "$3")
|
|
case "$mb,$2" in
|
|
"$2,$mb") info "Update is fast-forward" ;;
|
|
*) deny >/dev/null "This is not a fast-forward update." ;;
|
|
esac
|
|
fi
|
|
;;
|
|
*)
|
|
deny >/dev/null \
|
|
"Branch is not under refs/heads or refs/tags. What are you trying to do?"
|
|
;;
|
|
esac
|
|
|
|
# Implement per-branch controls based on username
|
|
allowed_users_file=$GIT_DIR/info/allowed-users
|
|
username=$(id -u -n)
|
|
info "The user is: '$username'"
|
|
|
|
if [ -f "$allowed_users_file" ]; then
|
|
rc=$(cat $allowed_users_file | grep -v '^#' | grep -v '^$' |
|
|
while read head_pattern user_patterns; do
|
|
matchlen=$(expr "$1" : "$head_pattern")
|
|
if [ "$matchlen" == "${#1}" ]; then
|
|
info "Found matching head pattern: '$head_pattern'"
|
|
for user_pattern in $user_patterns; do
|
|
info "Checking user: '$username' against pattern: '$user_pattern'"
|
|
matchlen=$(expr "$username" : "$user_pattern")
|
|
if [ "$matchlen" == "${#username}" ]; then
|
|
grant "Allowing user: '$username' with pattern: '$user_pattern'"
|
|
fi
|
|
done
|
|
deny "The user is not in the access list for this branch"
|
|
fi
|
|
done
|
|
)
|
|
case "$rc" in
|
|
grant) grant >/dev/null "Granting access based on $allowed_users_file" ;;
|
|
deny) deny >/dev/null "Denying access based on $allowed_users_file" ;;
|
|
*) ;;
|
|
esac
|
|
fi
|
|
|
|
allowed_groups_file=$GIT_DIR/info/allowed-groups
|
|
groups=$(id -G -n)
|
|
info "The user belongs to the following groups:"
|
|
info "'$groups'"
|
|
|
|
if [ -f "$allowed_groups_file" ]; then
|
|
rc=$(cat $allowed_groups_file | grep -v '^#' | grep -v '^$' |
|
|
while read head_pattern group_patterns; do
|
|
matchlen=$(expr "$1" : "$head_pattern")
|
|
if [ "$matchlen" == "${#1}" ]; then
|
|
info "Found matching head pattern: '$head_pattern'"
|
|
for group_pattern in $group_patterns; do
|
|
for groupname in $groups; do
|
|
info "Checking group: '$groupname' against pattern: '$group_pattern'"
|
|
matchlen=$(expr "$groupname" : "$group_pattern")
|
|
if [ "$matchlen" == "${#groupname}" ]; then
|
|
grant "Allowing group: '$groupname' with pattern: '$group_pattern'"
|
|
fi
|
|
done
|
|
done
|
|
deny "None of the user's groups are in the access list for this branch"
|
|
fi
|
|
done
|
|
)
|
|
case "$rc" in
|
|
grant) grant >/dev/null "Granting access based on $allowed_groups_file" ;;
|
|
deny) deny >/dev/null "Denying access based on $allowed_groups_file" ;;
|
|
*) ;;
|
|
esac
|
|
fi
|
|
|
|
deny >/dev/null "There are no more rules to check. Denying access"
|
|
|
|
-- >8 -- end of script -- >8 --
|
|
|
|
This uses two files, $GIT_DIR/info/allowed-users and
|
|
allowed-groups, to describe which heads can be pushed into by
|
|
whom. The format of each file would look like this:
|
|
|
|
refs/heads/master junio
|
|
refs/heads/cogito$ pasky
|
|
refs/heads/bw/ linus
|
|
refs/heads/tmp/ *
|
|
refs/tags/v[0-9]* junio
|
|
|
|
With this, Linus can push or create "bw/penguin" or "bw/zebra"
|
|
or "bw/panda" branches, Pasky can do only "cogito", and JC can
|
|
do master branch and make versioned tags. And anybody can do
|
|
tmp/blah branches.
|
|
|
|
------------
|