How to fix 'Address already in use' error

Question

I am still trying to use browsermob-proxy (here) to try to monitor the network traffic during a python selenium test (see browsermobproxypy). I am using the following script to test it:

from browsermobproxy import Server
server = Server("/home/adietz/Projects/Invest/browsermob-proxy/browsermob-proxy-2.1.4/bin/browsermob-proxy")
server.start()
proxy = server.create_proxy()

from selenium import webdriver
profile  = webdriver.FirefoxProfile()
profile.set_proxy(proxy.selenium_proxy())
driver = webdriver.Firefox(firefox_profile=profile)


proxy.new_har("google")
driver.get("http://www.google.co.in")
proxy.har

server.stop()
driver.quit()

I somehow managed to install a 'browsermob.jar' file (which is not really nicely described in the documentation here; you have to download the jar files from here). I am starting the proxy as follows:

java -jar ./browsermob-proxy-2.1.4/lib/browsermob-dist-2.1.4.jar --port 9090
Running BrowserMob Proxy using LittleProxy implementation. To revert to the legacy implementation, run the proxy with the command-line option '--use-littleproxy false'.
[INFO  2018-01-18T07:47:20,761 net.lightbody.bmp.proxy.Main] (main) Starting BrowserMob Proxy version 2.1.4 
[INFO  2018-01-18T07:47:20,782 org.eclipse.jetty.util.log] (main) jetty-7.x.y-SNAPSHOT 
[INFO  2018-01-18T07:47:20,802 org.eclipse.jetty.util.log] (main) started o.e.j.s.ServletContextHandler{/,null} 
[INFO  2018-01-18T07:47:20,885 org.eclipse.jetty.util.log] (main) Started SelectChannelConnector@0.0.0.0:9090 

Then I am running the test script as

python tester1.py

However, in the logs I see errors like follows:

[WARN  2018-01-18T07:28:30,265 org.eclipse.jetty.util.log] (main) FAILED SelectChannelConnector@0.0.0.0:8080: java.net.BindException: Address already in use 
[WARN  2018-01-18T07:28:30,266 org.eclipse.jetty.util.log] (main) FAILED org.eclipse.jetty.server.Server@4b41e4dd: java.net.BindException: Address already in use 
[ERROR 2018-01-18T07:28:30,266 net.lightbody.bmp.proxy.Main] (main) Failed to start Jetty server. Aborting. java.net.BindException: Address already in use
    at sun.nio.ch.Net.bind0(Native Method) ~[?:1.8.0_151]
    at sun.nio.ch.Net.bind(Net.java:433) ~[?:1.8.0_151]
    at sun.nio.ch.Net.bind(Net.java:425) ~[?:1.8.0_151]
    at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223) ~[?:1.8.0_151]
    at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74) ~[?:1.8.0_151]
    at org.eclipse.jetty.server.nio.SelectChannelConnector.open(SelectChannelConnector.java:162) ~[browsermob-dist-2.1.4.jar:?]
    at org.eclipse.jetty.server.AbstractConnector.doStart(AbstractConnector.java:356) ~[browsermob-dist-2.1.4.jar:?]
    at org.eclipse.jetty.server.nio.SelectChannelConnector.doStart(SelectChannelConnector.java:240) ~[browsermob-dist-2.1.4.jar:?]
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:55) ~[browsermob-dist-2.1.4.jar:?]
    at org.eclipse.jetty.server.Server.doStart(Server.java:269) ~[browsermob-dist-2.1.4.jar:?]
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:55) ~[browsermob-dist-2.1.4.jar:?]
    at net.lightbody.bmp.proxy.Main.main(Main.java:64) [browsermob-dist-2.1.4.jar:?]

My best guess is that the port is already in use, or something else is not working correctly. Maybe I need to explicitly specify the port in the script? But how to do that? A python documentation is virtually not-existing ...

Addendum

• Looking at the source code(!) I figured out how to set the port. I am using the following line to define the server and the port in the python script:

  server = Server("/home/adietz/Projects/Invest/browsermob-proxy/browsermob-proxy-2.1.4/bin/browsermob-proxy", {'port':9090})

But no matter what I set as the port I always get the following error:

Traceback (most recent call last):
  File "tester1.py", line 5, in <module>
    proxy = server.create_proxy()
  File "/home/adietz/Projects/Invest/browsermob-proxy/venv_browsermob/local/lib/python2.7/site-packages/browsermobproxy/server.py", line 40, in create_proxy
    client = Client(self.url[7:], params)
  File "/home/adietz/Projects/Invest/browsermob-proxy/venv_browsermob/local/lib/python2.7/site-packages/browsermobproxy/client.py", line 37, in __init__
    "Another server running on this port?\n%s..." % content[:512])
Exception: Could not read Browsermob-Proxy json
Another server running on this port?
java.lang.RuntimeException: java.net.BindException: Address already in use
    at org.littleshoot.proxy.impl.DefaultHttpProxyServer.doStart(DefaultHttpProxyServer.java:545)
    at org.littleshoot.proxy.impl.DefaultHttpProxyServer.start(DefaultHttpProxyServer.java:489)
    at org.littleshoot.proxy.impl.DefaultHttpProxyServer.access$700(DefaultHttpProxyServer.java:69)
    at org.littleshoot.proxy.impl.DefaultHttpProxyServer$DefaultHttpProxyServerBootstrap.start(DefaultHttpProxyServer.java:858)
    at net.lightbody.bmp.Brows...

So there must be something else working incorrectly...

Maybe I will just code such a proxy on my own. Seems to be the faster way...

Answer 1

We can start the BMP server with required port as given below. server accepts dictionary object for server arguments.

from browsermobproxy import Server
dict={'port':8090}
server = Server(path="C:\\Projects\\BrowserMobProxy\\bin\\browsermob-proxy",options=dict)
server.start()
proxy = server.create_proxy()

from selenium import webdriver
profile  = webdriver.FirefoxProfile()
profile.set_proxy(proxy.selenium_proxy())
driver = webdriver.Firefox(firefox_profile=profile)


proxy.new_har("google")
driver.get("http://www.google.co.uk")
proxy.har # returns a HAR JSON blob

server.stop()
driver.quit()

Answer 2

Initialize the server with this -

proxyserver =  Server(
       path="/root/tests/bsp_usecase_tests/bin/browsermob-proxy",
       options={'existing_proxy_port_to_use': 8090})

The internal code in Browsermob-Proxy is looking for key in 'options' dictionary named 'existing_proxy_port_to_use', else it uses default i.e. empty dictionary.