first round of changes to improve builder (make functions more modular) and start of work to add tags

Author: vsoch

examples/package_image/package_images.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+
+# This is an example of generating image packages from within python
+
+import os
+import shutil
+from singularity.cli import get_image
+from singularity.package import package
+
+# Save packages here
+output_folder = '/home/vanessa/Documents/Dropbox/Code/singularity/singularity-python/examples/package_image/packages'
+
+# Here are my images. I'm lazy so I'm going to use all docker
+# https://github.com/docker-library/official-images/tree/master/library
+images = ['aerospike','alpine','amazonlinux','arangodb','backdrop','bash','bonita','buildpack-deps',
+          'busybox','cassandra','celery','centos','chronograf','cirros','clearlinux','clojure','composer',
+          'consul','couchbase','couchdb','crate','crux','debian','django','docker','drupal','eclipse-mosquitto',
+          'eggdrop','elasticsearch','elixir','erlang','fedora','fsharp','gazebo','gcc','ghost','golang','haproxy',
+          'haskell','hello-world','httpd','hylang','ibmjava','influxdb','iojs','irssi','java','jenkins','jetty',
+          'joomla','jruby','julia','kaazing-gateway','kapacitor','kibana','known','kong','lightstreamer',
+          'logstash','mageia','mariadb','maven','memcached','mongo','mongo-express','mono','mysql','nats',
+          'nats-streaming','neo4j','neurodebian','nextcloud','nginx','node','notary','nuxeo','odoo','openjdk',
+          'opensuse','oraclelinux','orientdb','owncloud','percona','perl','photon','php','php-zendserver',
+          'piwik','plone','postgres','pypy','python','r-base','rabbitmq','rails','rakudo-star','redis',
+          'redmine','registry','rethinkdb','rocket.chat','ros','ruby','sentry','solr','sonarqube','sourcemage',
+          'spiped','storm','swarm','telegraf','thrift','tomcat','tomee','traefik','ubuntu','vault',
+          'websphere-liberty','wordpress','zookeeper']
+
+# You will need to export your sudopw to an environment variable called pancakes for it to not ask you :)
+os.environ['pancakes'] = 'yoursecretpass'
+
+for name in images:
+    docker_image = "docker://%s:latest" %(name)
+    image = get_image(docker_image)
+    package_name = "%s/%s.zip" %(output_folder,os.path.basename(image))
+    if not os.path.exists(package_name):
+        image_package = package(image_path=image,
+                                output_folder=output_folder,
+                                remove_image=True,
+                                runscript=True,
+                                software=True)
+    tmpfolder = os.path.dirname(image)
+
+