Add fabric task for installing PHP Composer

https://getcomposer.org/

rattail/fablib/composer.py

@@ -0,0 +1,47 @@
+# -*- coding: utf-8; -*-
+################################################################################
+#
+#  Rattail -- Retail Software Framework
+#  Copyright © 2010-2017 Lance Edgar
+#
+#  This file is part of Rattail.
+#
+#  Rattail is free software: you can redistribute it and/or modify it under the
+#  terms of the GNU Affero General Public License as published by the Free
+#  Software Foundation, either version 3 of the License, or (at your option)
+#  any later version.
+#
+#  Rattail is distributed in the hope that it will be useful, but WITHOUT ANY
+#  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#  FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
+#  more details.
+#
+#  You should have received a copy of the GNU Affero General Public License
+#  along with Rattail.  If not, see <http://www.gnu.org/licenses/>.
+#
+################################################################################
+"""
+Fabric lib for Composer (PHP dependency manager)
+"""
+
+from __future__ import unicode_literals, absolute_import
+
+from fabric.api import sudo
+from fabric.contrib.files import exists
+
+from rattail.fablib import make_deploy
+
+
+deploy = make_deploy(__file__)
+
+
+def install_composer(user=None):
+    """
+    Install `composer.phar` in current directory
+    """
+    if not exists('composer.phar'):
+        deploy('composer/install-composer.sh', 'install-composer.sh')
+        sudo('./install-composer.sh')
+        sudo('rm install-composer.sh')
+        if user:
+            sudo('chown {}: composer.phar'.format(user))

rattail/fablib/deploy/composer/install-composer.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+EXPECTED_SIGNATURE=$(wget -q -O - https://composer.github.io/installer.sig)
+php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
+ACTUAL_SIGNATURE=$(php -r "echo hash_file('SHA384', 'composer-setup.php');")
+
+if [ "$EXPECTED_SIGNATURE" != "$ACTUAL_SIGNATURE" ]
+then
+    >&2 echo 'ERROR: Invalid installer signature'
+    rm composer-setup.php
+    exit 1
+fi
+
+php composer-setup.php --quiet
+RESULT=$?
+rm composer-setup.php
+exit $RESULT