How to catch response of server in mitmproxy container and past it into file in json format?

Question

I need to catch and fill in separated file every response,request which is going through my mitmproxy container.

Dockerfile

FROM mitmproxy/mitmproxy:latest

RUN mkdir url_catching
WORKDIR /home/$USER/url_catching
COPY ./url.py .



EXPOSE 8080:8080

ENTRYPOINT ["/usr/bin/mitmdump","-s","./url.py"]

Docker run

sudo docker run --rm -it -p 8080:8080 mitmdump_url:latest

My pyhton script(sry, i am novice in python)

from mitmproxy import http

def response(flow):
    url_request: str = str(flow.request.pretty_url)
    url_request = url_request.replace("/", "_")
    with open(url_request, "ab") as ofile:
        ofile.write(flow.request.pretty_url.encode())
        ofile.write(flow.request.content)
        ofile.write(flow.response.content)

• in the result i get separated files for each request and name of it is equal to url of request, but only url is in human readable format everything else is encoded or just missed. So i need to past response which is going through my proxy in json format to files.

Answer 1

request/responde has headers + empty line + body/content

I show two methods to convert headers to string/bytes.

As normal lines of text

for key, value in flow.response.headers.items():
    ofile.write('{}: {}\n'.format(key, value).encode())

Result

Access-Control-Allow-Credentials: true
Access-Control-Allow-Origin: *
Content-Encoding: gzip
Content-Type: application/json
Date: Tue, 14 Jan 2020 11:51:49 GMT
Referrer-Policy: no-referrer-when-downgrade
Server: nginx
X-Content-Type-Options: nosniff
X-Frame-Options: DENY
X-XSS-Protection: 1; mode=block
Content-Length: 181
Connection: keep-alive

As JSON. I convert to dict() because headers can't be directly converted to JSON

d = dict(flow.request.headers.items())
d = json.dumps(d, indents=2)
ofile.write(d.encode() + b'\n')

Result

{
  "Host": "httpbin.org",
  "User-Agent": "python-requests/2.22.0",
  "Accept-Encoding": "gzip, deflate",
  "Accept": "*/*",
  "Connection": "keep-alive"
}

I also skip urls with '/static/'

from mitmproxy import http
import json

def response(flow):
    url_request: str = str(flow.request.pretty_url)

    if '/static/' not in url_request:
        url_request = url_request.replace("/", "_")
        with open(url_request + '.txt', "ab") as ofile:

            ofile.write(b'--- url ---\n')
            ofile.write(flow.request.pretty_url.encode() + b'\n')

            ofile.write(b'--- request ---\n')

            ofile.write(b'--- headers ---\n')
            #for key, value in flow.request.headers.items():
            #    ofile.write('{}: {}\n'.format(key, value).encode())
            d = dict(flow.request.headers.items())
            d = json.dumps(d, indents=2)
            ofile.write(d.encode() + b'\n')


            ofile.write(b'--- content ---\n')
            ofile.write(flow.request.content + b'\n')

            ofile.write(b'--- response ---\n')

            ofile.write(b'--- headers ---\n')
            for key, value in flow.response.headers.items():
                ofile.write('{}: {}\n'.format(key, value).encode())

            ofile.write(b'--- content ---\n')
            ofile.write(flow.response.content + b'\n')

To put all as one JSON you would have to first create dictionary with all elements (headers, body, etc.) and next use json.dumps(all_elements)

---

Testing code

import requests

proxy = {
    'http': 'http://localhost:8080',
    'https': 'http://localhost:8080',
}

urls = [
    'https://httpbin.org/get',
    'https://httpbin.org/gzip',
    'https://httpbin.org/brotli',
    'https://httpbin.org/deflate',
    'https://httpbin.org/encoding/utf8',
]

for url in urls:
    print(url)
    r = requests.get(url, proxies=proxy, verify=False)
    print(r.text)

One of file with results

--- url ---
https://httpbin.org/get
--- request ---
--- headers ---
{
  "Host": "httpbin.org",
  "User-Agent": "python-requests/2.22.0",
  "Accept-Encoding": "gzip, deflate",
  "Accept": "*/*",
  "Connection": "keep-alive"
}
--- content ---

--- response ---
--- headers ---
Access-Control-Allow-Credentials: true
Access-Control-Allow-Origin: *
Content-Encoding: gzip
Content-Type: application/json
Date: Tue, 14 Jan 2020 12:06:04 GMT
Referrer-Policy: no-referrer-when-downgrade
Server: nginx
X-Content-Type-Options: nosniff
X-Frame-Options: DENY
X-XSS-Protection: 1; mode=block
Content-Length: 181
Connection: keep-alive
--- content ---
{
  "args": {}, 
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "gzip, deflate", 
    "Host": "httpbin.org", 
    "User-Agent": "python-requests/2.22.0"
  }, 
  "origin": "83.23.66.224, 83.23.66.224", 
  "url": "https://httpbin.org/get"
}