OpenStack中给wsgi程序写单元測试的方法

在 OpenStack 中, 针对web应用, 有三种方法来写单元測试

1) 使用webob生成模拟的request

from __future__ import print_function
import webob
import testtools


def hello_world(env, start_response):
    if env['PATH_INFO'] != '/':
        start_response('404 Not Found', [('Content-Type', 'text/plain')])
        return ['Not Found\r\n']

    start_response('200 OK', [('Content-Type', 'text/plain')])
    return ['hello world!']

class WsgiAppTestCase(testtools.TestCase):

    def test_hello_world_with_webob(self):
        resp = webob.Request.blank('/').get_response(hello_world)

        print("resp=%s" % (resp))

        self.assertEqual(resp.status_code, 200)
        self.assertEqual(resp.body, "hello world!")

2) 使用webtest生成模拟的request

from __future__ import print_function
import webtest
import testtools


def hello_world(env, start_response):
    if env['PATH_INFO'] != '/':
        start_response('404 Not Found', [('Content-Type', 'text/plain')])
        return ['Not Found\r\n']

    start_response('200 OK', [('Content-Type', 'text/plain')])
    return ['hello world!']


class WsgiAppTestCase(testtools.TestCase):

    def test_hello_world_with_webtest(self):
        app = webtest.TestApp(hello_world)
        resp = app.get('/')
        print("resp=%s" % (resp))

        self.assertEqual(resp.status_code, 200)
        self.assertEqual(resp.body, "hello world!")

3) 启动一个wsgi server, 并发送真实的 HTTP请求

这样的办法最复杂, 须要下面步骤

• 调用eventlet包, 开启monkey_patch模式
• 使用eventlet包, 创建一个socket, 并在127.0.0.1:8080上做监听
• 使用eventlet包, 创建一个wsgi server
  
• 使用httplib2包, 发送一个HTTP数据包给server

from __future__ import print_function
import httplib2
import socket
import testtools


def hello_world(env, start_response):
    if env['PATH_INFO'] != '/':
        start_response('404 Not Found', [('Content-Type', 'text/plain')])
        return ['Not Found\r\n']

    start_response('200 OK', [('Content-Type', 'text/plain')])
    return ['hello world!']


class WsgiAppTestCase(testtools.TestCase):

    def test_hello_world_with_eventlet(self):
        import eventlet
        eventlet.monkey_patch(os=False)

        bind_addr = ("127.0.0.1","8080")
        try:
            info = socket.getaddrinfo(bind_addr[0],
                                      bind_addr[1],
                                      socket.AF_UNSPEC,
                                      socket.SOCK_STREAM)[0]
            family = info[0]
            bind_addr = info[-1]
        except Exception:
            family = socket.AF_INET

        sock = eventlet.listen(bind_addr, family)
            
        wsgi_kwargs = {
            'func': eventlet.wsgi.server,
            'sock': sock,
            'site': hello_world,
            'protocol': eventlet.wsgi.HttpProtocol,
            'debug': False
            }

        server = eventlet.spawn(**wsgi_kwargs)
        
        client = httplib2.Http()
        resp, body = client.request(
            "http://127.0.0.1:8080", "get", headers=None, body=None)
        print("resp=%s, body=%s" % (resp, body))

        self.assertEqual(resp.status, 200)
        self.assertEqual(body, "hello world!")
        
        server.kill()