Renew instance from agent

vm_renewal

+#!/usr/bin/python
+
+import notify
+
+if __name__ == '__main__':
+    try:
+        notify.accept()
+    finally:
+        pass

notify.py

+        logger.error("Incorrect function call")
+    else:
+        process = subprocess.Popen("wall", stdin=subprocess.PIPE, shell=True)
+        process.communicate(input=text)[0]
+
+
+def accept():
+    import httplib
+    if not os.path.isfile("%s/%s" % (get_temp_dir(), file_name)):
+        logger.error("There isn't a request received currently")
+    else:
+        done = False
+        # Load the saved url
+        url = pickle.load(open("%s/%s" % (get_temp_dir(), file_name), "rb"))
+        headers = {"Content-type": "application/x-www-form-urlencoded", "Accept": "text/plain"}
+        # Delete https:// or http:// from beginning

notify.py

+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+##
+# Test program that informs the user about vm incoming time out
+##
+
+import platform, logging, os, subprocess, webbrowser, sys
+if sys.hexversion < 0x03000000 and sys.hexversion > 0x02000000:

notify.py

+#!/usr/bin/python

vm_renewal

-#!/usr/bin/python
+#!/usr/bin/env python
import notify
if __name__ == '__main__':
try:
notify.accept()
-    finally:
-        pass
+    except:
+        notify.wall("There was an unknown error while trying to renew this vm, please do it manually!")

[Őry Máté]

hm?

[Csók Tamás]

command for accepting the proposed renewal, what user needs to type down at a console client (vm_renewal) to renew his suspension time. Any ideas to do it better?

ps: (This file needs to be in the path enviroment variable ofc)

[Őry Máté]

try: ... finally: pass is equivalent to ....

[Csók Tamás]

Is it? I thought try catches all the exceptions whereas without it, it could go out

[Őry Máté]

except is the one which catches exceptions :) the body of the finally clause is only guaranteed to run after the others

[Csók Tamás]

So a try without a catch phase is useless :D

[Őry Máté]

urlparse module could help, but urllib.Request wouldn't even need to parse the url

[Csók Tamás]

I checked into this. If we switch to urllib2 we still need to generate a fake data so we achive that the urllib2 sends a POST instead of a GET and in the response we loose the ability to easily check the headers. Even checking the returned page status code requires 2.6+ python. Are you sure it's worth the switch? I remember I ran into this problem when i made this code, but i double checked it now, to be sure.

So it would look something like this:

# Load the saved url
url = pickle.load(open("%s/%s" % (get_temp_dir(), file_name), "rb"))
# Fake data to post so we make urllib2 send a POST instead of a GET
data = urllib.urlencode(dict(fromPhyton='True'))
# do POST request to 
req = urllib2.Request(url, data)
rsp = urllib2.urlopen(req)     
# Get the result of the request - NOTE: only works past 2.6+ python
if rsp.getcode() == 200:
    logger.info("Successfull renew, 200 - OK")
    done = True
elif rsp.getcode() == 302:
    logger.info("Response is 302 - FOUND")
    done = True
else:
    logger.error("Renewal failed please try it manually at %s" % url)
# POST request was sent and received successfully
if done:
    wall("Successfull renewal of this vm!")
    os.remove("%s/%s" % (get_temp_dir(), file_name))

[Őry Máté]

• we do have python2.6+
• urllib2 code seems much better
• data="" is more simple
• you can both get the response and send custom request headers

req = Request("http://postcatcher.in/catchers/53d0c38b10b71c02000004c5", "", {'x-hello': 3})
resp = urlopen(req)

resp.info()['x-powered-by']
# OUT: 'Express'

[Csók Tamás]

I feel bad now. I stand corrected, and already modified the code.

[Őry Máté]

try: ... except ImporError? (btw python supports a < b < c form)

[Csók Tamás]

Dosen't that just only makes it more pythonic or using a < b < c have benefits in runtime over the current one? And sure it can be changed to try except format too if needed.

But maybe it would be even better to delete the whole checking as I recently learned about 2to3 python tool, which renders this useless

[Őry Máté]

or you could even use json :) in this case i wouldn't care the run time of this expression, but the compact form must be slightly quicker as it evaluates b only once

[Csók Tamás]

So the question is I feel that this if statement is pointless, shall I remove it? I mean can I edit the code while it's under revision?

[Őry Máté]

yes and yes

[Őry Máté]

#!/usr/bin/env python is more portable

[Őry Máté]

Not really.

[Őry Máté]

you could simply print this

[Csók Tamás]

I could, but the main idea was to spam the user with information about the incoming suspension. Shouldn't a renew error be spammed too? Considering the other errors are all wall-ed too.

[Őry Máté]

They will call this command in a terminal, they will see its output as well.

[Csók Tamás]

Shall I change all the rest of the accept method texts as well then?

[Őry Máté]

please

[Csók Tamás]

done :)