You will need to stop the reactor when the spider finishes. You can accomplish this by listening for the spider_closed signal:
from twisted.internet import reactor
from scrapy import log, signals
from scrapy.crawler import Crawler
from scrapy.settings import Settings
from scrapy.xlib.pydispatch import dispatcher
from testspiders.spiders.followall import FollowAllSpider
def stop_reactor():
reactor.stop()
dispatcher.connect(stop_reactor, signal=signals.spider_closed)
spider = FollowAllSpider(domain='scrapinghub.com')
crawler = Crawler(Settings())
crawler.configure()
crawler.crawl(spider)
crawler.start()
log.start()
log.msg('Running reactor...')
reactor.run() # the script will block here until the spider is closed
log.msg('Reactor stopped.')
And the command line log output might look something like:
stav@maia:/srv/scrapy/testspiders$ ./api
2013-02-10 14:49:38-0600 [scrapy] INFO: Running reactor...
2013-02-10 14:49:47-0600 [followall] INFO: Closing spider (finished)
2013-02-10 14:49:47-0600 [followall] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 23934,...}
2013-02-10 14:49:47-0600 [followall] INFO: Spider closed (finished)
2013-02-10 14:49:47-0600 [scrapy] INFO: Reactor stopped.
stav@maia:/srv/scrapy/testspiders$