cluster-update

#!/bin/bash

set -e

# cmd line
cmd="$0"
refname="$1"
oldrev="$2"
newrev="$3"

sanity_checks() {
	if [ -z "$GIT_DIR" ]; then
		echo "Don't run this script from the command line." >&2
		echo " (if you want, you could supply GIT_DIR then run" >&2
		echo "  $cmd <ref> <oldrev> <newrev>)" >&2
		exit 1
	fi

	if [ -z "$refname" -o -z "$oldrev" -o -z "$newrev" ]; then
		echo "Usage: $cmd <ref> <oldrev> <newrev>" >&2
		exit 1
	fi
}

get_defaults() {
	# Check if there are frozen branches
	frozenbranchesfilter="no"
	[ -f $GIT_DIR/frozenbranches ] && frozenbranchesfilter="yes"

	# Check for protected branches
	protectedbranchesfilter="no"
	[ -f $GIT_DIR/protectedbranches ] && protectedbranchesfilter="yes"

	# Check if we should enable or not tag filter protection
	protectedtagfilter="no"
	[ -f $GIT_DIR/protectedtagfilter ] && protectedtagfilter="yes"

	# Check if there are branches we want to mail (private branches can be quiet)
	mailbranchesfilter="no"
	[ -f $GIT_DIR/mailbranches ] && mailbranchesfilter="yes"

	[ -f $GIT_DIR/commit-list ] && recipients=$(cat $GIT_DIR/commit-list)
	# XXX remember to change default recipients
	[ -n "$recipients" ] || recipients=fabbione@fabbione.net

	# Don't add shortmodule name to Subject in output email
	skip_shortmodule=""
	[ -f $GIT_DIR/skip_shortmodule ] && skip_shortmodule=yes

	projectdesc=$(sed -ne '1p' "$GIT_DIR/description")
	if expr "$projectdesc" : "Unnamed repository.*$" >/dev/null; then
		projectdesc="UNNAMED PROJECT"
	fi

	if [ -z "$mailer" ]; then
		mailer="/usr/bin/send-unicode-email.py"
	fi
}

# this sets change_type and rev_type vars to something we can use
get_commit_type() {
	if expr "$oldrev" : '0*$' >/dev/null; then
		change_type="create"
	else
		if expr "$newrev" : '0*$' >/dev/null; then
			change_type="delete"
		else
			change_type="update"
		fi
	fi

	case "$change_type" in
		create|update)
			rev_type="$(git cat-file -t $newrev 2> /dev/null)"
			;;
		delete)
			rev_type="delete"
			;;
	esac
}

# set very_short_name, short_refname and refname_type.
# very_short_name is handy for branch filtering.
get_short_refname() {
	very_short_name="$(echo $refname | awk -F "/" '{print $NF}')"
	case "$refname" in
		refs/tags/*)
			short_refname=${refname##refs/tags/}
			;;
		refs/heads/*)
			short_refname=${refname##refs/heads}
			;;
		refs/remotes/*)
			short_refname=${refname##refs/remotes/}
			;;
	esac
	case "$refname","$rev_type" in
		refs/tags/*,commit|refs/tags/*,delete)
			# un-annotated tag
			refname_type="tag"
			;;
		refs/tags/*,tag)
			# annotated tag
			refname_type="annotated tag"
			;;
		refs/heads/*,commit|refs/heads/*,delete)
			# branch
			refname_type="branch"
			;;
		refs/remotes/*,commit|refs/remotes/*,delete)
			# tracking branch
			refname_type="tracking branch"
			;;
	esac
}

filter_frozen_branches() {
	if [ "$frozenbranchesfilter" = "yes" ]; then
		if grep -q ^${very_short_name}$ $GIT_DIR/frozenbranches; then
			echo "*** $very_short_name branch is frozen and cannot be changed" >&2
			exit 1
		fi
	fi
}

# this policy filter makes sure that selected branches cannot be deleted
# and that tags cannot be removed
filter_delete_type() {
	case "$refname","$change_type" in
		refs/tags/*,delete)
			if [ "$protectedtagfilter" = "yes" ]; then
				# we don't allow tag removal
				echo "*** Deleting a tag is not allowed in this repository" >&2
				exit 1
			fi
			;;
		refs/heads/*,delete|refs/remotes/*,delete)
			# delete branch
			if [ "$protectedbranchesfilter" = "yes" ]; then
				if grep -q ^${very_short_name}$ $GIT_DIR/protectedbranches; then
					echo "*** $very_short_name branch cannot be deleted" >&2
					exit 1
				fi
			fi
			;;
	esac
}

# tell us if we should mail about a certain branch or not
filter_mail_branches() {
	if [ "$refname_type" = "branch" ] || [ "$refname_type" = "tracking branch" ]; then
		if [ "$mailbranchesfilter" = "yes" ]; then
			if ! grep -q ^${very_short_name}$ $GIT_DIR/mailbranches; then
				# no mail for this branch. We exit clean, it's not a failure
				exit 0
			fi
		fi
	fi
}

# generate_email_* functions look aweful but it is only a lot of
# escaping to format the emails nicely.

generate_email_branch_commit() {
	base=$(git-merge-base "$oldrev" "$newrev")
	commits=$(git-rev-list --reverse "$newrev" "^$base")

	for i in $commits; do
		git show --patch-with-stat --pretty=format:"\
\
Subject: ${shortmodule}$very_short_name - %s%n\
To: $recipient%n\
X-Project: $projectdesc%n\
X-Git-Module: $module%n\
X-Git-Refname: $refname%n\
X-Git-Reftype: $refname_type%n\
X-Git-Oldrev: %P%n\
X-Git-Newrev: %H%n\
%n\
Gitweb:        http://git.fedorahosted.org/git/?p=$module;a=commitdiff;h=%H%n\
Commit:        %H%n\
Parent:        %P%n\
Author:        %an <%ae>%n\
AuthorDate:    %ad%n\
Committer:     %cn <%ce>%n\
CommitterDate: %cd%n\
%n%s%n%n%b" \
		$i | $mailer $recipient

		# try to serialize outgoing emails without flooding when pushing
		# lots of commits at once
		sleep 2
	done
}

generate_email_delete() {
	(echo -e "\
Subject: ${shortmodule}$very_short_name $refname_type - deleted\n\
To: $recipient\n\
X-Project: $projectdesc\n\
X-Git-Module: $module\n\
X-Git-Refname: $refname\n\
X-Git-Reftype: $refname_type\n\
X-Git-Oldrev: $oldrev
X-Git-Newrev: $newrev\n\
\n\
$refname_type: $very_short_name - deleted with refnum:\n";
git show -s --pretty=oneline $oldrev) | $mailer $recipient
}

generate_email_atag() {
	taginfo="$(git cat-file tag $newrev)"
	eval $(echo "$taginfo" | sed -n '1s/ /=/p')
	eval $(echo "$taginfo" | sed -n '2s/ /=/p')
	eval $(echo "$taginfo" | sed -n '3s/ /=/p')
	tagger=$(echo "$taginfo" | sed -n '4s/tagger \([^>]*>\)[^0-9]*\([0-9]*\).*/\1/p')
	ts=$(echo "$taginfo" | sed -n '4s/tagger \([^>]*>\)[^0-9]*\([0-9]*\).*/\2/p')
	date=$(date --date="1970-01-01 00:00:00 $ts seconds" +"%F %R %z")

	(echo -e "\
Subject: ${shortmodule}$very_short_name $refname_type has been ${change_type}d\n\
To: $recipient\n\
X-Project: $projectdesc\n\
X-Git-Module: $module\n\
X-Git-Refname: $refname\n\
X-Git-Reftype: $refname_type\n\
X-Git-Oldrev: $oldrev
X-Git-Newrev: $newrev\n\
\n\
Gitweb:        http://git.fedorahosted.org/git/?p=$module;a=commitdiff;h=$newrev\n\
Commit:        $newrev\n\
Parent:        $oldrev\n\
Author:        $tagger\n\
AuthorDate:    $date\n\
Committer:     $tagger\n\
CommitterDate: $date\n\
\n\
$refname_type: $very_short_name has been ${change_type}d
$(if [ $change_type = create ]; then
	echo -e "\t    at $newrev ($rev_type)\n";
  else
	echo -e "\t      to $newrev ($rev_type)\n\tfrom $oldrev (which is now obsolete)\n";
  fi)
       tagging $object ($type)\n\
$(if [ $type = commit ]; then
	prevtag=$(git describe --abbrev=0 $newrev^ 2>/dev/null);
	if [ -n "$prevtag" ]; then
		echo "      replaces $prevtag";
	fi
fi)
$(git cat-file tag $newrev | sed -n '5,$p')
\n\
$(if [ $type = commit ]; then
	prevtag=$(git describe --abbrev=0 $newrev^ 2>/dev/null);
	if [ -n "$prevtag" ]; then
		git rev-list --pretty=short "$prevtag..$newrev" | git shortlog
	else
		git rev-list --pretty=short $newrev | git shortlog
	fi
fi)\
";) | $mailer $recipient
}

generate_email_uatag() {
	git show --summary --pretty=format:"\
\
Subject: ${shortmodule}$very_short_name $refname_type has been ${change_type}d%n\
To: $recipient%n\
X-Project: $projectdesc%n\
X-Git-Module: $module%n\
X-Git-Refname: $refname%n\
X-Git-Reftype: $refname_type%n" \
		| $mailer $recipient

}

generate_email() {
	# common stuff

	module=$(basename `readlink -f $GIT_DIR`)

	shortmodule=""
	[ -z "$skip_shortmodule" ] && shortmodule="${module%%.git}: "

	# like all the other scripts around we need to generate emails
	# according to the type of chance. No kidding.. it's a mess of
	# combinations

	case "$refname","$rev_type" in
		refs/tags/*,commit)
			# un-annotated tag
			generate_email_uatag
			;;
		refs/tags/*,tag)
			# annotated tag
			generate_email_atag
			;;
		refs/tags/*,delete)
			# delete tag
			generate_email_delete
			;;
		refs/heads/*,commit)
			# branch
			generate_email_branch_commit
			;;
		refs/heads/*,delete)
			# delete branch
			generate_email_delete
			;;
		refs/remotes/*,commit)
			# tracking branch
			echo "*** Push-update of tracking branch, $refname" >&2
			echo "***  - no email generated." >&2
			# This can be made quiet.. ???
			;;
		refs/remotes/*,delete)
			# delete tracking branch
			generate_email_delete
			;;
	esac
}

### main

sanity_checks

# get some info around
get_defaults
get_commit_type
get_short_refname

# apply filters
filter_frozen_branches
filter_delete_type
filter_mail_branches

# if we are here we need to send an email.. go figure.. :)

set +e # we don't want to kill a commit if we fail to send an email
for recipient in $recipients; do
	generate_email
done

exit 0