post-receive: Add modified post-receive hook for Git.
authorTed Zlatanov <tzz@lifelogs.com>
Wed, 1 Sep 2010 11:04:46 +0000 (06:04 -0500)
committerTed Zlatanov <tzz@lifelogs.com>
Wed, 1 Sep 2010 11:04:46 +0000 (06:04 -0500)
* post-receive: Add modified post-receive hook for Git.

etc/ChangeLog
etc/post-receive [new file with mode: 0755]

index 0799ee7..4199f4e 100644 (file)
@@ -1,3 +1,7 @@
+2010-09-01  Teodor Zlatanov  <tzz@lifelogs.com>
+
+       * post-receive: Add modified post-receive hook for Git.
+
 2010-03-22  Teodor Zlatanov  <tzz@lifelogs.com>
 
        * gnus/gnus-setup.ast: Add finish links to the top nodes.
diff --git a/etc/post-receive b/etc/post-receive
new file mode 100755 (executable)
index 0000000..de7e28d
--- /dev/null
@@ -0,0 +1,706 @@
+#!/bin/sh
+
+# 2010-09-01 tzz@lifelogs.com
+
+# Use the email address of the author of the last commit.
+export USER_EMAIL=$(git log -1 --format=format:%ae HEAD)
+export USER_NAME=$(git log -1 --format=format:%an HEAD)
+
+# the remainder is the standard git-core post-receive-email with some changes:
+
+# - USER_EMAIL is used in the header
+# - USER_NAME is used in the header
+
+# Copyright (c) 2007 Andy Parkins
+#
+# An example hook script to mail out commit update information.  This hook
+# sends emails listing new revisions to the repository introduced by the
+# change being reported.  The rule is that (for branch updates) each commit
+# will appear on one email and one email only.
+#
+# This hook is stored in the contrib/hooks directory.  Your distribution
+# will have put this somewhere standard.  You should make this script
+# executable then link to it in the repository you would like to use it in.
+# For example, on debian the hook is stored in
+# /usr/share/doc/git-core/contrib/hooks/post-receive-email:
+#
+#  chmod a+x post-receive-email
+#  cd /path/to/your/repository.git
+#  ln -sf /usr/share/doc/git-core/contrib/hooks/post-receive-email hooks/post-receive
+#
+# This hook script assumes it is enabled on the central repository of a
+# project, with all users pushing only to it and not between each other.  It
+# will still work if you don't operate in that style, but it would become
+# possible for the email to be from someone other than the person doing the
+# push.
+#
+# Config
+# ------
+# hooks.mailinglist
+#   This is the list that all pushes will go to; leave it blank to not send
+#   emails for every ref update.
+# hooks.announcelist
+#   This is the list that all pushes of annotated tags will go to.  Leave it
+#   blank to default to the mailinglist field.  The announce emails lists
+#   the short log summary of the changes since the last annotated tag.
+# hooks.envelopesender
+#   If set then the -f option is passed to sendmail to allow the envelope
+#   sender address to be set
+# hooks.emailprefix
+#   All emails have their subjects prefixed with this prefix, or "[SCM]"
+#   if emailprefix is unset, to aid filtering
+# hooks.showrev
+#   The shell command used to format each revision in the email, with
+#   "%s" replaced with the commit id.  Defaults to "git rev-list -1
+#   --pretty %s", displaying the commit id, author, date and log
+#   message.  To list full patches separated by a blank line, you
+#   could set this to "git show -C %s; echo".
+#   To list a gitweb/cgit URL *and* a full patch for each change set, use this:
+#     "t=%s; printf 'http://.../?id=%%s' \$t; echo;echo; git show -C \$t; echo"
+#   Be careful if "..." contains things that will be expanded by shell "eval"
+#   or printf.
+#
+# Notes
+# -----
+# All emails include the headers "X-Git-Refname", "X-Git-Oldrev",
+# "X-Git-Newrev", and "X-Git-Reftype" to enable fine tuned filtering and
+# give information for debugging.
+#
+
+# ---------------------------- Functions
+
+#
+# Top level email generation function.  This decides what type of update
+# this is and calls the appropriate body-generation routine after outputting
+# the common header
+#
+# Note this function doesn't actually generate any email output, that is
+# taken care of by the functions it calls:
+#  - generate_email_header
+#  - generate_create_XXXX_email
+#  - generate_update_XXXX_email
+#  - generate_delete_XXXX_email
+#  - generate_email_footer
+#
+generate_email()
+{
+       # --- Arguments
+       oldrev=$(git rev-parse $1)
+       newrev=$(git rev-parse $2)
+       refname="$3"
+
+       # --- Interpret
+       # 0000->1234 (create)
+       # 1234->2345 (update)
+       # 2345->0000 (delete)
+       if expr "$oldrev" : '0*$' >/dev/null
+       then
+               change_type="create"
+       else
+               if expr "$newrev" : '0*$' >/dev/null
+               then
+                       change_type="delete"
+               else
+                       change_type="update"
+               fi
+       fi
+
+       # --- Get the revision types
+       newrev_type=$(git cat-file -t $newrev 2> /dev/null)
+       oldrev_type=$(git cat-file -t "$oldrev" 2> /dev/null)
+       case "$change_type" in
+       create|update)
+               rev="$newrev"
+               rev_type="$newrev_type"
+               ;;
+       delete)
+               rev="$oldrev"
+               rev_type="$oldrev_type"
+               ;;
+       esac
+
+       # The revision type tells us what type the commit is, combined with
+       # the location of the ref we can decide between
+       #  - working branch
+       #  - tracking branch
+       #  - unannoted tag
+       #  - annotated tag
+       case "$refname","$rev_type" in
+               refs/tags/*,commit)
+                       # un-annotated tag
+                       refname_type="tag"
+                       short_refname=${refname##refs/tags/}
+                       ;;
+               refs/tags/*,tag)
+                       # annotated tag
+                       refname_type="annotated tag"
+                       short_refname=${refname##refs/tags/}
+                       # change recipients
+                       if [ -n "$announcerecipients" ]; then
+                               recipients="$announcerecipients"
+                       fi
+                       ;;
+               refs/heads/*,commit)
+                       # branch
+                       refname_type="branch"
+                       short_refname=${refname##refs/heads/}
+                       ;;
+               refs/remotes/*,commit)
+                       # tracking branch
+                       refname_type="tracking branch"
+                       short_refname=${refname##refs/remotes/}
+                       echo >&2 "*** Push-update of tracking branch, $refname"
+                       echo >&2 "***  - no email generated."
+                       exit 0
+                       ;;
+               *)
+                       # Anything else (is there anything else?)
+                       echo >&2 "*** Unknown type of update to $refname ($rev_type)"
+                       echo >&2 "***  - no email generated"
+                       exit 1
+                       ;;
+       esac
+
+       # Check if we've got anyone to send to
+       if [ -z "$recipients" ]; then
+               case "$refname_type" in
+                       "annotated tag")
+                               config_name="hooks.announcelist"
+                               ;;
+                       *)
+                               config_name="hooks.mailinglist"
+                               ;;
+               esac
+               echo >&2 "*** $config_name is not set so no email will be sent"
+               echo >&2 "*** for $refname update $oldrev->$newrev"
+               exit 0
+       fi
+
+       # Email parameters
+       # The email subject will contain the best description of the ref
+       # that we can build from the parameters
+       describe=$(git describe $rev 2>/dev/null)
+       if [ -z "$describe" ]; then
+               describe=$(git log -1 --format=oneline $rev 2>/dev/null)
+       fi
+
+       if [ -z "$describe" ]; then
+               describe=$rev
+       fi
+
+       generate_email_header
+
+       # Call the correct body generation function
+       fn_name=general
+       case "$refname_type" in
+       "tracking branch"|branch)
+               fn_name=branch
+               ;;
+       "annotated tag")
+               fn_name=atag
+               ;;
+       esac
+       generate_${change_type}_${fn_name}_email
+
+       generate_email_footer
+}
+
+generate_email_header()
+{
+       # --- Email (all stdout will be the email)
+       # Generate header
+       cat <<-EOF
+       From: ${USER_NAME} <${USER_EMAIL}>
+       To: $recipients
+       Subject: ${emailprefix}$projectdesc $refname_type, $short_refname, ${change_type}d. $describe
+       X-Git-Refname: $refname
+       X-Git-Reftype: $refname_type
+       X-Git-Oldrev: $oldrev
+       X-Git-Newrev: $newrev
+
+       EOF
+}
+
+generate_email_footer()
+{
+       SPACE=" "
+       cat <<-EOF
+       
+       This is an automated email from the git hooks/post-receive script. It was
+       generated because a ref change was pushed to the repository containing
+       the project "$projectdesc".
+
+       The $refname_type, $short_refname has been ${change_type}d
+
+
+       hooks/post-receive
+       --${SPACE}
+       $projectdesc
+       EOF
+}
+
+# --------------- Branches
+
+#
+# Called for the creation of a branch
+#
+generate_create_branch_email()
+{
+       # This is a new branch and so oldrev is not valid
+       echo "        at  $newrev ($newrev_type)"
+       echo ""
+
+       echo $LOGBEGIN
+       show_new_revisions
+       echo $LOGEND
+}
+
+#
+# Called for the change of a pre-existing branch
+#
+generate_update_branch_email()
+{
+       # Consider this:
+       #   1 --- 2 --- O --- X --- 3 --- 4 --- N
+       #
+       # O is $oldrev for $refname
+       # N is $newrev for $refname
+       # X is a revision pointed to by some other ref, for which we may
+       #   assume that an email has already been generated.
+       # In this case we want to issue an email containing only revisions
+       # 3, 4, and N.  Given (almost) by
+       #
+       #  git rev-list N ^O --not --all
+       #
+       # The reason for the "almost", is that the "--not --all" will take
+       # precedence over the "N", and effectively will translate to
+       #
+       #  git rev-list N ^O ^X ^N
+       #
+       # So, we need to build up the list more carefully.  git rev-parse
+       # will generate a list of revs that may be fed into git rev-list.
+       # We can get it to make the "--not --all" part and then filter out
+       # the "^N" with:
+       #
+       #  git rev-parse --not --all | grep -v N
+       #
+       # Then, using the --stdin switch to git rev-list we have effectively
+       # manufactured
+       #
+       #  git rev-list N ^O ^X
+       #
+       # This leaves a problem when someone else updates the repository
+       # while this script is running.  Their new value of the ref we're
+       # working on would be included in the "--not --all" output; and as
+       # our $newrev would be an ancestor of that commit, it would exclude
+       # all of our commits.  What we really want is to exclude the current
+       # value of $refname from the --not list, rather than N itself.  So:
+       #
+       #  git rev-parse --not --all | grep -v $(git rev-parse $refname)
+       #
+       # Get's us to something pretty safe (apart from the small time
+       # between refname being read, and git rev-parse running - for that,
+       # I give up)
+       #
+       #
+       # Next problem, consider this:
+       #   * --- B --- * --- O ($oldrev)
+       #          \
+       #           * --- X --- * --- N ($newrev)
+       #
+       # That is to say, there is no guarantee that oldrev is a strict
+       # subset of newrev (it would have required a --force, but that's
+       # allowed).  So, we can't simply say rev-list $oldrev..$newrev.
+       # Instead we find the common base of the two revs and list from
+       # there.
+       #
+       # As above, we need to take into account the presence of X; if
+       # another branch is already in the repository and points at some of
+       # the revisions that we are about to output - we don't want them.
+       # The solution is as before: git rev-parse output filtered.
+       #
+       # Finally, tags: 1 --- 2 --- O --- T --- 3 --- 4 --- N
+       #
+       # Tags pushed into the repository generate nice shortlog emails that
+       # summarise the commits between them and the previous tag.  However,
+       # those emails don't include the full commit messages that we output
+       # for a branch update.  Therefore we still want to output revisions
+       # that have been output on a tag email.
+       #
+       # Luckily, git rev-parse includes just the tool.  Instead of using
+       # "--all" we use "--branches"; this has the added benefit that
+       # "remotes/" will be ignored as well.
+
+       # List all of the revisions that were removed by this update, in a
+       # fast-forward update, this list will be empty, because rev-list O
+       # ^N is empty.  For a non-fast-forward, O ^N is the list of removed
+       # revisions
+       fast_forward=""
+       rev=""
+       for rev in $(git rev-list $newrev..$oldrev)
+       do
+               revtype=$(git cat-file -t "$rev")
+               echo "  discards  $rev ($revtype)"
+       done
+       if [ -z "$rev" ]; then
+               fast_forward=1
+       fi
+
+       # List all the revisions from baserev to newrev in a kind of
+       # "table-of-contents"; note this list can include revisions that
+       # have already had notification emails and is present to show the
+       # full detail of the change from rolling back the old revision to
+       # the base revision and then forward to the new revision
+       for rev in $(git rev-list $oldrev..$newrev)
+       do
+               revtype=$(git cat-file -t "$rev")
+               echo "       via  $rev ($revtype)"
+       done
+
+       if [ "$fast_forward" ]; then
+               echo "      from  $oldrev ($oldrev_type)"
+       else
+               #  1. Existing revisions were removed.  In this case newrev
+               #     is a subset of oldrev - this is the reverse of a
+               #     fast-forward, a rewind
+               #  2. New revisions were added on top of an old revision,
+               #     this is a rewind and addition.
+
+               # (1) certainly happened, (2) possibly.  When (2) hasn't
+               # happened, we set a flag to indicate that no log printout
+               # is required.
+
+               echo ""
+
+               # Find the common ancestor of the old and new revisions and
+               # compare it with newrev
+               baserev=$(git merge-base $oldrev $newrev)
+               rewind_only=""
+               if [ "$baserev" = "$newrev" ]; then
+                       echo "This update discarded existing revisions and left the branch pointing at"
+                       echo "a previous point in the repository history."
+                       echo ""
+                       echo " * -- * -- N ($newrev)"
+                       echo "            \\"
+                       echo "             O -- O -- O ($oldrev)"
+                       echo ""
+                       echo "The removed revisions are not necessarilly gone - if another reference"
+                       echo "still refers to them they will stay in the repository."
+                       rewind_only=1
+               else
+                       echo "This update added new revisions after undoing existing revisions.  That is"
+                       echo "to say, the old revision is not a strict subset of the new revision.  This"
+                       echo "situation occurs when you --force push a change and generate a repository"
+                       echo "containing something like this:"
+                       echo ""
+                       echo " * -- * -- B -- O -- O -- O ($oldrev)"
+                       echo "            \\"
+                       echo "             N -- N -- N ($newrev)"
+                       echo ""
+                       echo "When this happens we assume that you've already had alert emails for all"
+                       echo "of the O revisions, and so we here report only the revisions in the N"
+                       echo "branch from the common base, B."
+               fi
+       fi
+
+       echo ""
+       if [ -z "$rewind_only" ]; then
+               echo "Those revisions listed above that are new to this repository have"
+               echo "not appeared on any other notification email; so we list those"
+               echo "revisions in full, below."
+
+               echo ""
+               echo $LOGBEGIN
+               show_new_revisions
+
+               # XXX: Need a way of detecting whether git rev-list actually
+               # outputted anything, so that we can issue a "no new
+               # revisions added by this update" message
+
+               echo $LOGEND
+       else
+               echo "No new revisions were added by this update."
+       fi
+
+       # The diffstat is shown from the old revision to the new revision.
+       # This is to show the truth of what happened in this change.
+       # There's no point showing the stat from the base to the new
+       # revision because the base is effectively a random revision at this
+       # point - the user will be interested in what this revision changed
+       # - including the undoing of previous revisions in the case of
+       # non-fast-forward updates.
+       echo ""
+       echo "Summary of changes:"
+       git diff-tree --stat --summary --find-copies-harder $oldrev..$newrev
+}
+
+#
+# Called for the deletion of a branch
+#
+generate_delete_branch_email()
+{
+       echo "       was  $oldrev"
+       echo ""
+       echo $LOGEND
+       git show -s --pretty=oneline $oldrev
+       echo $LOGEND
+}
+
+# --------------- Annotated tags
+
+#
+# Called for the creation of an annotated tag
+#
+generate_create_atag_email()
+{
+       echo "        at  $newrev ($newrev_type)"
+
+       generate_atag_email
+}
+
+#
+# Called for the update of an annotated tag (this is probably a rare event
+# and may not even be allowed)
+#
+generate_update_atag_email()
+{
+       echo "        to  $newrev ($newrev_type)"
+       echo "      from  $oldrev (which is now obsolete)"
+
+       generate_atag_email
+}
+
+#
+# Called when an annotated tag is created or changed
+#
+generate_atag_email()
+{
+       # Use git for-each-ref to pull out the individual fields from the
+       # tag
+       eval $(git for-each-ref --shell --format='
+       tagobject=%(*objectname)
+       tagtype=%(*objecttype)
+       tagger=%(taggername)
+       tagged=%(taggerdate)' $refname
+       )
+
+       echo "   tagging  $tagobject ($tagtype)"
+       case "$tagtype" in
+       commit)
+
+               # If the tagged object is a commit, then we assume this is a
+               # release, and so we calculate which tag this tag is
+               # replacing
+               prevtag=$(git describe --abbrev=0 $newrev^ 2>/dev/null)
+
+               if [ -n "$prevtag" ]; then
+                       echo "  replaces  $prevtag"
+               fi
+               ;;
+       *)
+               echo "    length  $(git cat-file -s $tagobject) bytes"
+               ;;
+       esac
+       echo " tagged by  $tagger"
+       echo "        on  $tagged"
+
+       echo ""
+       echo $LOGBEGIN
+
+       # Show the content of the tag message; this might contain a change
+       # log or release notes so is worth displaying.
+       git cat-file tag $newrev | sed -e '1,/^$/d'
+
+       echo ""
+       case "$tagtype" in
+       commit)
+               # Only commit tags make sense to have rev-list operations
+               # performed on them
+               if [ -n "$prevtag" ]; then
+                       # Show changes since the previous release
+                       git rev-list --pretty=short "$prevtag..$newrev" | git shortlog
+               else
+                       # No previous tag, show all the changes since time
+                       # began
+                       git rev-list --pretty=short $newrev | git shortlog
+               fi
+               ;;
+       *)
+               # XXX: Is there anything useful we can do for non-commit
+               # objects?
+               ;;
+       esac
+
+       echo $LOGEND
+}
+
+#
+# Called for the deletion of an annotated tag
+#
+generate_delete_atag_email()
+{
+       echo "       was  $oldrev"
+       echo ""
+       echo $LOGEND
+       git show -s --pretty=oneline $oldrev
+       echo $LOGEND
+}
+
+# --------------- General references
+
+#
+# Called when any other type of reference is created (most likely a
+# non-annotated tag)
+#
+generate_create_general_email()
+{
+       echo "        at  $newrev ($newrev_type)"
+
+       generate_general_email
+}
+
+#
+# Called when any other type of reference is updated (most likely a
+# non-annotated tag)
+#
+generate_update_general_email()
+{
+       echo "        to  $newrev ($newrev_type)"
+       echo "      from  $oldrev"
+
+       generate_general_email
+}
+
+#
+# Called for creation or update of any other type of reference
+#
+generate_general_email()
+{
+       # Unannotated tags are more about marking a point than releasing a
+       # version; therefore we don't do the shortlog summary that we do for
+       # annotated tags above - we simply show that the point has been
+       # marked, and print the log message for the marked point for
+       # reference purposes
+       #
+       # Note this section also catches any other reference type (although
+       # there aren't any) and deals with them in the same way.
+
+       echo ""
+       if [ "$newrev_type" = "commit" ]; then
+               echo $LOGBEGIN
+               git show --no-color --root -s --pretty=medium $newrev
+               echo $LOGEND
+       else
+               # What can we do here?  The tag marks an object that is not
+               # a commit, so there is no log for us to display.  It's
+               # probably not wise to output git cat-file as it could be a
+               # binary blob.  We'll just say how big it is
+               echo "$newrev is a $newrev_type, and is $(git cat-file -s $newrev) bytes long."
+       fi
+}
+
+#
+# Called for the deletion of any other type of reference
+#
+generate_delete_general_email()
+{
+       echo "       was  $oldrev"
+       echo ""
+       echo $LOGEND
+       git show -s --pretty=oneline $oldrev
+       echo $LOGEND
+}
+
+
+# --------------- Miscellaneous utilities
+
+#
+# Show new revisions as the user would like to see them in the email.
+#
+show_new_revisions()
+{
+       # This shows all log entries that are not already covered by
+       # another ref - i.e. commits that are now accessible from this
+       # ref that were previously not accessible
+       # (see generate_update_branch_email for the explanation of this
+       # command)
+
+       # Revision range passed to rev-list differs for new vs. updated
+       # branches.
+       if [ "$change_type" = create ]
+       then
+               # Show all revisions exclusive to this (new) branch.
+               revspec=$newrev
+       else
+               # Branch update; show revisions not part of $oldrev.
+               revspec=$oldrev..$newrev
+       fi
+
+       other_branches=$(git for-each-ref --format='%(refname)' refs/heads/ |
+           grep -F -v $refname)
+       git rev-parse --not $other_branches |
+       if [ -z "$custom_showrev" ]
+       then
+               git rev-list --pretty --stdin $revspec
+       else
+               git rev-list --stdin $revspec |
+               while read onerev
+               do
+                       eval $(printf "$custom_showrev" $onerev)
+               done
+       fi
+}
+
+
+send_mail()
+{
+       if [ -n "$envelopesender" ]; then
+               /usr/sbin/sendmail -t -f "$envelopesender"
+       else
+               /usr/sbin/sendmail -t
+       fi
+}
+
+# ---------------------------- main()
+
+# --- Constants
+LOGBEGIN="- Log -----------------------------------------------------------------"
+LOGEND="-----------------------------------------------------------------------"
+
+# --- Config
+# Set GIT_DIR either from the working directory, or from the environment
+# variable.
+GIT_DIR=$(git rev-parse --git-dir 2>/dev/null)
+if [ -z "$GIT_DIR" ]; then
+       echo >&2 "fatal: post-receive: GIT_DIR not set"
+       exit 1
+fi
+
+projectdesc=$(sed -ne '1p' "$GIT_DIR/description")
+# Check if the description is unchanged from it's default, and shorten it to
+# a more manageable length if it is
+if expr "$projectdesc" : "Unnamed repository.*$" >/dev/null
+then
+       projectdesc="UNNAMED PROJECT"
+fi
+
+recipients=$(git config hooks.mailinglist)
+announcerecipients=$(git config hooks.announcelist)
+envelopesender=$(git config hooks.envelopesender)
+emailprefix=$(git config hooks.emailprefix || echo '[SCM] ')
+custom_showrev=$(git config hooks.showrev)
+
+# --- Main loop
+# Allow dual mode: run from the command line just like the update hook, or
+# if no arguments are given then run as a hook script
+if [ -n "$1" -a -n "$2" -a -n "$3" ]; then
+       # Output to the terminal in command line mode - if someone wanted to
+       # resend an email; they could redirect the output to sendmail
+       # themselves
+       PAGER= generate_email $2 $3 $1
+else
+       while read oldrev newrev refname
+       do
+               generate_email $oldrev $newrev $refname | send_mail
+       done
+fi