[lmi-commits] [lmi] master 0eafcb0: Make a non-bare repository sharable by multiple users

[Greg Chicares]

branch: master
commit 0eafcb048a2043867128d14773ea73de92f04b0a
Author: Gregory W. Chicares <address@hidden>
Commit: Gregory W. Chicares <address@hidden>

    Make a non-bare repository sharable by multiple users
---
 gwc/share_git2.sh | 98 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)

diff --git a/gwc/share_git2.sh b/gwc/share_git2.sh
new file mode 100755
index 0000000..0b2d7c9
--- /dev/null
+++ b/gwc/share_git2.sh
@@ -0,0 +1,98 @@
+#!/bin/sh
+
+# Attempt to set up a git repository to be shared by multiple users.
+
+# Unlike 'share_git1.sh', this script creates a non-bare repository.
+
+set -v
+
+# Start with a fresh throwaway directory.
+cd /tmp || exit
+rm -rf /tmp/eraseme
+mkdir -p /tmp/eraseme
+cd /tmp/eraseme || exit
+
+# Expect group users to include 'pulse' as well as normal user:
+getent group audio
+
+# Get this over with early. Reason: if script is piped into 'less',
+# type the password before the screen fills and password characters
+# are treated as 'less' commands.
+sudo --user=pulse true
+
+# First method: emulate git-clone as three git commands, with
+# a single 'chgrp' call at exactly the right spot.
+
+mkdir nonbare
+# Need to run 'chmod' because git didn't create this directory.
+chmod g+sw nonbare
+git init --shared nonbare
+chgrp -R audio nonbare
+git -C nonbare remote add origin https://github.com/wxWidgets/zlib.git
+git -C nonbare fetch origin
+
+find ./nonbare ! -perm -g=w |sed -e'/objects\/pack/d'
+# Oops: FETCH_HEAD doesn't have group permissions:
+ls -l ./nonbare/.git/FETCH_HEAD
+chmod g+w nonbare/.git/FETCH_HEAD
+ls -l ./nonbare/.git/FETCH_HEAD
+
+# This isn't really necessary; it just makes the result look more like
+# that of the second method, below.
+git -C nonbare pack-refs --all
+
+# Generate index and worktree:
+git -C nonbare checkout master
+
+# This succeeds when run by owner:
+git -C nonbare fetch
+# This succeeds because FETCH_HEAD's permissions were fixed above:
+sudo --user=pulse git -C nonbare fetch
+
+# Need to do this after fetching, for the worktree.
+chmod -R g=u nonbare
+
+# Second method: git-clone, and fix up permissions manually
+
+git clone --jobs=32 --config core.SharedRepository=group 
https://github.com/wxWidgets/zlib.git
+chgrp -R audio zlib
+# This is better than 'chmod -R g+s' (it affects only directories):
+find zlib -type d -exec chmod g+s {} +
+# Specifying 's' here causes many 'S' occurrences in 'ls' output:
+# chmod -R g+swX zlib
+# Specifying 'g+w' here would cause pack files to be group writable:
+chmod -R g=u zlib
+# Why doesn't 'g=u' override the earlier 'g+s'?
+
+find ./zlib ! -perm -g=w |sed -e'/objects\/pack/d'
+
+# This succeeds when run by owner:
+git -C zlib fetch
+
+find ./zlib ! -perm -g=w |sed -e'/objects\/pack/d'
+# Oops: FETCH_HEAD doesn't have group permissions:
+ls -l ./zlib/.git/FETCH_HEAD
+chmod g+w zlib/.git/FETCH_HEAD
+ls -l ./zlib/.git/FETCH_HEAD
+
+# This succeeds because FETCH_HEAD's permissions were fixed above:
+sudo --user=pulse git -C zlib fetch
+
+# The two methods produce somewhat similar results. Sizes:
+du -sb zlib nonbare/
+# are almost the same. Small differences:
+#  - nonbare/.git/config has this extra line under [remote "origin"]:
+#      fetch = +refs/heads/*:refs/remotes/origin/*
+#    (which is just a default)
+#  - HEAD is
+#      refs/heads/master  [in zlib]
+#      refs/heads/wx      [in nonbare]
+#    though both seem to point to the same SHA1
+#  - git-fsck complains about an unborn branch, in nonbare only:
+git -C zlib fsck
+git -C nonbare fsck
+
+# List all files' permissions for comparison, e.g.:
+#   meld /srv/chroot/bullseye0/tmp/eraseme/ls-* &
+cd /tmp/eraseme/nonbare && ls -alR >/tmp/eraseme/ls-nonbare
+cd /tmp/eraseme/zlib    && ls -alR >/tmp/eraseme/ls-zlib