restub 1.12

RESTub - REST Service Mocking

RESTUB is a library for creating HTTP stubs


Preamble

Often while developing there is a need to create some HTTP stub. Frequent solutions of this problem among developers are:
- Using shareware and non-free software, like SoapUI
- Creating service from scratch, for example, using a Flask
- For unit-tests, using such packages as requests-mock

Each of these solutions has the right for life. I needed free, completely transparent and simple package creating a really existing server in system. A server that could be invoked both from code and applications, like browser or curl. I found a lot of similar libraries, but for various reasons they did not fit me. So the restub appeared.

Main functionality:
- Automatic addition of necessary headers according to a contents type
- Tracing of an output of requests and responses
- Support of regular expressions in URL
- Emulation of a slow connection
- Support of HTTPS


Routes and routing

A route represents the ordered sequence of values (method, path, data, headers, status) describing data which we can receive at the specified address and a method of access. Therefore the method of access and the address is a required and other values can be omitted.

method — an access method, can be "GET", "POST", "PUT" or "DELETE"
path — describing the response address, can be regex
*data — response data, can be str or dict
*headers — HTTP response headers
*status — code of the response status

When data passed the headers Content-type and Content-length will be automatically added in response. Of course, you can always override these headers. Having sent the dict as data the header 'Content-type' with the value 'application/json' will be added. When str passed, the following scenarios are possible:
- If the str is a path to the file existing in system, contents of this file will be load in a body of response. At the same time, if the extension of the file has a matching with one of CTYPES values (the dictionary containing often used formats of data, such as “css”, “js”, “ttf”, etc), the Content-type will be taken there
- If the str represents json, xml or html document, then the Content-type will have the corresponding values: 'application/json', 'application/xml' or 'text/html'
- In all other cases, data will be transferred as 'text/plain'


Running

The stub can be run as a context manager, a decorator of function or as a class instance. Before the run of a stub at least one route has to be defined. The address where the stub is started can be received through the property - host. By default the stub is available at the address http://localhost:8081 or https://localhost:8081 if the secure mode was enabled.

Run as the a context manager with a change of port:
```
from restub import Service

with Service(routes=['GET', r'/$'], port=7777) as srv:
# your requests here
```

Run as the decorator of function:
```
from restub import Service

@Service(routes=['GET', r'/$'])
def stubbed_func():
# your requests here
```

Run as the class instance:
```
from restub import Service

srv = Service(routes=['GET', r'/$'])
srv.start()
# your requests here
srv.stop()
```

Run as the class instance and definition of routes through the functions of the same name:
```
from restub import Service

srv = Service()
srv.get(r'/$') # post(..), put(..), delete(..)
srv.start()
# your requests here
srv.stop()
```

For work with HTTPS it is necessary to set **secure** flag in True and pass absolute paths to a private key and a certificate:
```
from restub import Service

with Service(routes=['GET', r'/$'], secure=True, crt='<abs path to key>', key='<abs path to cert>'):
# your secured requests here
```

The private key and the certificate in linux can be generated by the command:
```
openssl req -new -x509 -days 365 -nodes -out restub.crt -keyout restub.key
```

The slow connection can be emulated through delay property. It specifies the delay per response in seconds:
```
from restub import Service

with Service(routes=['GET', r'/$'], delay=0.5) as srv:
# your delayed requests here
```

Tracing of an output of requests and responses turns on by the setting of trace flag in True:
```
from restub import Service

with Service(routes=['GET', r'/$'], trace=True) as srv:
# your requests with trace here
```