From 46232915d5ac84fb033ad395bbf161c9645c42c9 Mon Sep 17 00:00:00 2001 From: Josh England Date: Tue, 11 Sep 2007 10:59:03 -0600 Subject: Add post-merge hook, related documentation, and tests. The post-merge hook enables one to hook in for `git pull` operations in order to check and/or change attributes of a work tree from the hook. As an example, it can be used in combination with a pre-commit hook to save/restore file ownership and permissions data (or file ACLs) within the repository and transparently update the working tree after a `git pull` operation. Signed-off-by: Josh England Signed-off-by: Junio C Hamano diff --git a/Documentation/hooks.txt b/Documentation/hooks.txt index c39edc5..50535a7 100644 --- a/Documentation/hooks.txt +++ b/Documentation/hooks.txt @@ -87,6 +87,18 @@ parameter, and is invoked after a commit is made. This hook is meant primarily for notification, and cannot affect the outcome of `git-commit`. +post-merge +----------- + +This hook is invoked by `git-merge`, which happens when a `git pull` +is done on a local repository. The hook takes a single parameter, a status +flag specifying whether or not the merge being done was a squash merge. +This hook cannot affect the outcome of `git-merge`. + +This hook can be used in conjunction with a corresponding pre-commit hook to +save and restore any form of metadata associated with the working tree +(eg: permissions/ownership, ACLS, etc). + [[pre-receive]] pre-receive ----------- diff --git a/git-merge.sh b/git-merge.sh index 3a01db0..66e48b3 100755 --- a/git-merge.sh +++ b/git-merge.sh @@ -97,6 +97,19 @@ finish () { fi ;; esac + + # Run a post-merge hook + if test -x "$GIT_DIR"/hooks/post-merge + then + case "$squash" in + t) + "$GIT_DIR"/hooks/post-merge 1 + ;; + '') + "$GIT_DIR"/hooks/post-merge 0 + ;; + esac + fi } merge_name () { diff --git a/t/t5402-post-merge-hook.sh b/t/t5402-post-merge-hook.sh new file mode 100755 index 0000000..1c4b0b3 --- /dev/null +++ b/t/t5402-post-merge-hook.sh @@ -0,0 +1,56 @@ +#!/bin/sh +# +# Copyright (c) 2006 Josh England +# + +test_description='Test the post-merge hook.' +. ./test-lib.sh + +test_expect_success setup ' + echo Data for commit0. >a && + git update-index --add a && + tree0=$(git write-tree) && + commit0=$(echo setup | git commit-tree $tree0) && + echo Changed data for commit1. >a && + git update-index a && + tree1=$(git write-tree) && + commit1=$(echo modify | git commit-tree $tree1 -p $commit0) && + git update-ref refs/heads/master $commit0 && + git-clone ./. clone1 && + GIT_DIR=clone1/.git git update-index --add a && + git-clone ./. clone2 && + GIT_DIR=clone2/.git git update-index --add a +' + +for clone in 1 2; do + cat >clone${clone}/.git/hooks/post-merge <<'EOF' +#!/bin/sh +echo $@ >> $GIT_DIR/post-merge.args +EOF + chmod u+x clone${clone}/.git/hooks/post-merge +done + +test_expect_failure 'post-merge does not run for up-to-date ' ' + GIT_DIR=clone1/.git git merge $commit0 && + test -e clone1/.git/post-merge.args +' + +test_expect_success 'post-merge runs as expected ' ' + GIT_DIR=clone1/.git git merge $commit1 && + test -e clone1/.git/post-merge.args +' + +test_expect_success 'post-merge from normal merge receives the right argument ' ' + grep 0 clone1/.git/post-merge.args +' + +test_expect_success 'post-merge from squash merge runs as expected ' ' + GIT_DIR=clone2/.git git merge --squash $commit1 && + test -e clone2/.git/post-merge.args +' + +test_expect_success 'post-merge from squash merge receives the right argument ' ' + grep 1 clone2/.git/post-merge.args +' + +test_done -- cgit v0.10.2-6-g49f6 From af6fb4c822a5a65c7671d810127171759dff38f6 Mon Sep 17 00:00:00 2001 From: Josh England Date: Tue, 11 Sep 2007 10:59:04 -0600 Subject: Added example hook script to save/restore permissions/ownership. Usage info is emebed in the script, but the gist of it is to run the script from a pre-commit hook to save permissions/ownership data to a file and check that file into the repository. Then, a post_merge hook reads the file and updates working tree permissions/ownership. All updates are transparent to the user (although there is a --verbose option). Merge conflicts are handled in the "read" phase (in pre-commit), and the script aborts the commit and tells you how to fix things in the case of a merge conflict in the metadata file. This same idea could be extended to handle file ACLs or other file metadata if desired. Signed-off-by: Josh England Signed-off-by: Junio C Hamano diff --git a/Documentation/hooks.txt b/Documentation/hooks.txt index 50535a7..58b9547 100644 --- a/Documentation/hooks.txt +++ b/Documentation/hooks.txt @@ -97,7 +97,8 @@ This hook cannot affect the outcome of `git-merge`. This hook can be used in conjunction with a corresponding pre-commit hook to save and restore any form of metadata associated with the working tree -(eg: permissions/ownership, ACLS, etc). +(eg: permissions/ownership, ACLS, etc). See contrib/hooks/setgitperms.perl +for an example of how to do this. [[pre-receive]] pre-receive diff --git a/contrib/hooks/setgitperms.perl b/contrib/hooks/setgitperms.perl new file mode 100644 index 0000000..5e3b89d --- /dev/null +++ b/contrib/hooks/setgitperms.perl @@ -0,0 +1,213 @@ +#!/usr/bin/perl +# +# Copyright (c) 2006 Josh England +# +# This script can be used to save/restore full permissions and ownership data +# within a git working tree. +# +# To save permissions/ownership data, place this script in your .git/hooks +# directory and enable a `pre-commit` hook with the following lines: +# #!/bin/sh +# . git-sh-setup +# $GIT_DIR/hooks/setgitperms.perl -r +# +# To restore permissions/ownership data, place this script in your .git/hooks +# directory and enable a `post-merge` hook with the following lines: +# #!/bin/sh +# . git-sh-setup +# $GIT_DIR/hooks/setgitperms.perl -w +# +use strict; +use Getopt::Long; +use File::Find; +use File::Basename; + +my $usage = +"Usage: setgitperms.perl [OPTION]... <--read|--write> +This program uses a file `.gitmeta` to store/restore permissions and uid/gid +info for all files/dirs tracked by git in the repository. + +---------------------------------Read Mode------------------------------------- +-r, --read Reads perms/etc from working dir into a .gitmeta file +-s, --stdout Output to stdout instead of .gitmeta +-d, --diff Show unified diff of perms file (XOR with --stdout) + +---------------------------------Write Mode------------------------------------ +-w, --write Modify perms/etc in working dir to match the .gitmeta file +-v, --verbose Be verbose + +\n"; + +my ($stdout, $showdiff, $verbose, $read_mode, $write_mode); + +if ((@ARGV < 0) || !GetOptions( + "stdout", \$stdout, + "diff", \$showdiff, + "read", \$read_mode, + "write", \$write_mode, + "verbose", \$verbose, + )) { die $usage; } +die $usage unless ($read_mode xor $write_mode); + +my $topdir = `git-rev-parse --show-cdup` or die "\n"; chomp $topdir; +my $gitdir = $topdir . '.git'; +my $gitmeta = $topdir . '.gitmeta'; + +if ($write_mode) { + # Update the working dir permissions/ownership based on data from .gitmeta + open (IN, "<$gitmeta") or die "Could not open $gitmeta for reading: $!\n"; + while (defined ($_ = )) { + chomp; + if (/^(.*) mode=(\S+)\s+uid=(\d+)\s+gid=(\d+)/) { + # Compare recorded perms to actual perms in the working dir + my ($path, $mode, $uid, $gid) = ($1, $2, $3, $4); + my $fullpath = $topdir . $path; + my (undef,undef,$wmode,undef,$wuid,$wgid) = lstat($fullpath); + $wmode = sprintf "%04o", $wmode & 07777; + if ($mode ne $wmode) { + $verbose && print "Updating permissions on $path: old=$wmode, new=$mode\n"; + chmod oct($mode), $fullpath; + } + if ($uid != $wuid || $gid != $wgid) { + if ($verbose) { + # Print out user/group names instead of uid/gid + my $pwname = getpwuid($uid); + my $grpname = getgrgid($gid); + my $wpwname = getpwuid($wuid); + my $wgrpname = getgrgid($wgid); + $pwname = $uid if !defined $pwname; + $grpname = $gid if !defined $grpname; + $wpwname = $wuid if !defined $wpwname; + $wgrpname = $wgid if !defined $wgrpname; + + print "Updating uid/gid on $path: old=$wpwname/$wgrpname, new=$pwname/$grpname\n"; + } + chown $uid, $gid, $fullpath; + } + } + else { + warn "Invalid input format in $gitmeta:\n\t$_\n"; + } + } + close IN; +} +elsif ($read_mode) { + # Handle merge conflicts in the .gitperms file + if (-e "$gitdir/MERGE_MSG") { + if (`grep ====== $gitmeta`) { + # Conflict not resolved -- abort the commit + print "PERMISSIONS/OWNERSHIP CONFLICT\n"; + print " Resolve the conflict in the $gitmeta file and then run\n"; + print " `.git/hooks/setgitperms.perl --write` to reconcile.\n"; + exit 1; + } + elsif (`grep $gitmeta $gitdir/MERGE_MSG`) { + # A conflict in .gitmeta has been manually resolved. Verify that + # the working dir perms matches the current .gitmeta perms for + # each file/dir that conflicted. + # This is here because a `setgitperms.perl --write` was not + # performed due to a merge conflict, so permissions/ownership + # may not be consistent with the manually merged .gitmeta file. + my @conflict_diff = `git show \$(cat $gitdir/MERGE_HEAD)`; + my @conflict_files; + my $metadiff = 0; + + # Build a list of files that conflicted from the .gitmeta diff + foreach my $line (@conflict_diff) { + if ($line =~ m|^diff --git a/$gitmeta b/$gitmeta|) { + $metadiff = 1; + } + elsif ($line =~ /^diff --git/) { + $metadiff = 0; + } + elsif ($metadiff && $line =~ /^\+(.*) mode=/) { + push @conflict_files, $1; + } + } + + # Verify that each conflict file now has permissions consistent + # with the .gitmeta file + foreach my $file (@conflict_files) { + my $absfile = $topdir . $file; + my $gm_entry = `grep "^$file mode=" $gitmeta`; + if ($gm_entry =~ /mode=(\d+) uid=(\d+) gid=(\d+)/) { + my ($gm_mode, $gm_uid, $gm_gid) = ($1, $2, $3); + my (undef,undef,$mode,undef,$uid,$gid) = lstat("$absfile"); + $mode = sprintf("%04o", $mode & 07777); + if (($gm_mode ne $mode) || ($gm_uid != $uid) + || ($gm_gid != $gid)) { + print "PERMISSIONS/OWNERSHIP CONFLICT\n"; + print " Mismatch found for file: $file\n"; + print " Run `.git/hooks/setgitperms.perl --write` to reconcile.\n"; + exit 1; + } + } + else { + print "Warning! Permissions/ownership no longer being tracked for file: $file\n"; + } + } + } + } + + # No merge conflicts -- write out perms/ownership data to .gitmeta file + unless ($stdout) { + open (OUT, ">$gitmeta.tmp") or die "Could not open $gitmeta.tmp for writing: $!\n"; + } + + my @files = `git-ls-files`; + my %dirs; + + foreach my $path (@files) { + chomp $path; + # We have to manually add stats for parent directories + my $parent = dirname($path); + while (!exists $dirs{$parent}) { + $dirs{$parent} = 1; + next if $parent eq '.'; + printstats($parent); + $parent = dirname($parent); + } + # Now the git-tracked file + printstats($path); + } + + # diff the temporary metadata file to see if anything has changed + # If no metadata has changed, don't overwrite the real file + # This is just so `git commit -a` doesn't try to commit a bogus update + unless ($stdout) { + if (! -e $gitmeta) { + rename "$gitmeta.tmp", $gitmeta; + } + else { + my $diff = `diff -U 0 $gitmeta $gitmeta.tmp`; + if ($diff ne '') { + rename "$gitmeta.tmp", $gitmeta; + } + else { + unlink "$gitmeta.tmp"; + } + if ($showdiff) { + print $diff; + } + } + close OUT; + } + # Make sure the .gitmeta file is tracked + system("git add $gitmeta"); +} + + +sub printstats { + my $path = $_[0]; + $path =~ s/@/\@/g; + my (undef,undef,$mode,undef,$uid,$gid) = lstat($path); + $path =~ s/%/\%/g; + if ($stdout) { + print $path; + printf " mode=%04o uid=$uid gid=$gid\n", $mode & 07777; + } + else { + print OUT $path; + printf OUT " mode=%04o uid=$uid gid=$gid\n", $mode & 07777; + } +} -- cgit v0.10.2-6-g49f6