cron: Add script to update production web site checkout.

cron/cron.d/website-update

@@ -0,0 +1 @@
+*/5 * * * * www $HOME/website/cron/scripts/website-update.sh

cron/scripts/website-update.sh

@@ -0,0 +1,52 @@
+#!/bin/sh
+
+set -e
+set -u
+
+LOCKDIR="/tmp/website-update.$(id -u)"
+SITEDIR=~/website
+PRODUCTION_BRANCH=master
+DB_FILE=~/Database/conservancy-website.sqlite3
+DB_SCRIPT=~bkuhn/django-supporters-list.sql
+
+git_rev_name() {
+    git rev-parse --abbrev-ref --symbolic-full-name "$@"
+}
+
+if ! mkdir "$LOCKDIR"; then
+    test -d "$LOCKDIR"
+    exit $?
+fi
+trap 'rmdir "$LOCKDIR"' 0 INT TERM QUIT
+
+exitcode=0
+if [ "$DB_SCRIPT" -nt "$DB_FILE" ]; then
+    sqlite3 "$DB_FILE" <"$DB_SCRIPT" || exitcode=$?
+fi
+
+# If the checkout is not on the production branch,
+# assume maintenance is happening and stop.
+cd "$SITEDIR"
+if [ "$(git_rev_name HEAD)" != "$PRODUCTION_BRANCH" ]; then
+    exit "$exitcode"
+fi
+
+# Abort if the production branch isn't tracking a remote branch.
+if ! git_upstream="$(git_rev_name '@{upstream}' 2>/dev/null)"; then
+    exit 3
+fi
+
+IFS=/ read git_remote git_refspec <<EOF
+$git_upstream
+EOF
+git fetch --quiet --no-tags "$git_remote" "$git_refspec"
+if [ "$(git rev-parse "$PRODUCTION_BRANCH")" = "$(git rev-parse "$git_upstream")" ]; then
+    exit "$exitcode"
+fi
+
+git merge --quiet --ff-only "$git_remote" "$git_refspec"
+python2 -m compileall -q www || exitcode=$?
+chgrp -R www-data www || exitcode=$?
+chmod -R g+rX-w,o+X-w www || exitcode=$?
+chmod -R o+r www/conservancy/static || exitcode=$?
+exit "$exitcode"