Solved

Python: Notify if Error

Posted on 2011-02-11
10
436 Views
Last Modified: 2012-05-11
I have a script that stops and starts services on several servers (8). When it finishes, it sends me an email that the script has run successfully. I have the stderr going to a file also. what i want to do is read the file and do the following:

if error exists in output.log then send me an email
else
if no error exists continue with the script.


I know i  need to run this in the loop so that i get an email if there's an error. As it is now, i get an email when it completes looping through all of the servers and stops / restarts the services.

I'm only interested in either how to google examples of what i'm looking for, or resources that help me figure this out. I don't need it done for me. I'm not getting a clear picture of what that looks like in Python.

Thanks.

thanks.
0
Comment
Question by:huskeraider
  • 4
  • 4
  • 2
10 Comments
 
LVL 75

Accepted Solution

by:
käµfm³d   👽 earned 200 total points
ID: 34891514
http://docs.python.org/tutorial/controlflow.html


Take a look at section 4.4 (break and continue) for how to exit the loop; section 4.5 show an example of a while loop (you could probably use a for loop as well--see section 4.2).
0
 
LVL 28

Expert Comment

by:pepr
ID: 34892242
Huskeraider, can you show how you call the script that start services and how you redirect its output?  My guess is that you may want to use the subprocess.Popen() with suitable arguments to capture the produced output in your Python script and simply check the produced content.
0
 

Author Comment

by:huskeraider
ID: 34900406
I call a batch file that launches a ruby script that stops the service and listens until the service stops. I have the stderr going to a text file. I was going to check the text file for errors. if errors then email me. if not, complete the process and send "completed successfully" message.

Is that what you wanted to know?
0
Master Your Team's Linux and Cloud Stack!

The average business loses $13.5M per year to ineffective training (per 1,000 employees). Keep ahead of the competition and combine in-person quality with online cost and flexibility by training with Linux Academy.

 

Author Comment

by:huskeraider
ID: 34900443
Kaufmed,

thanks for the example. This is something i might be able to use in the layout i have.
0
 
LVL 28

Expert Comment

by:pepr
ID: 34900806
How complex the batch is? It is likely that it could be rewritten easily to Python (i.e. calling from Python the same things that are called from the batch).  Then it would be easy to capture the redirected stdout and stderr and to check their content. Can you show a representative fragment of the batch file (with how the redirection is done)?
0
 

Author Comment

by:huskeraider
ID: 34901168
I'm basically looking for an example of a If statement that reads and looks for certain text in a text file. if it finds "error" then it sends a error message. if there's nothing in the text file, it finishes and sends a completed message.

the batch has a ruby script that sends a stop request then it listens until the service is stopped. then it starts the service. when stopped it goes to the next server in the list.
0
 
LVL 28

Assisted Solution

by:pepr
pepr earned 300 total points
ID: 34902224
Basically, something like this:
    f = open('logfile.txt')
    errorFound = False
    for line in f:
        if line.startswith('error'):   # for the case you know how the error line starts
            errorFound = False         # set the flag
            break                      # terminate the loop early
    f.close()

    if errorFound:
        sendmail(...)

Open in new window


The good/bad result testing may vary.  You can use a regular expression to match more complex error-indication lines.

Does this make sense?
0
 
LVL 75

Expert Comment

by:käµfm³d 👽
ID: 34903814
@pepr

Line 5 should be

    errorFound = True

correct?
0
 
LVL 28

Expert Comment

by:pepr
ID: 34904334
@kaufmed: Yes :)   Thanks for spotting the error.
0
 

Author Closing Comment

by:huskeraider
ID: 34906683
Thank you both for your assistance both of these examples gives me what i need.

thanks again.
0

Featured Post

Best Practices: Disaster Recovery Testing

Besides backup, any IT division should have a disaster recovery plan. You will find a few tips below relating to the development of such a plan and to what issues one should pay special attention in the course of backup planning.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article will show the steps for installing Python on Ubuntu Operating System. I have created a virtual machine with Ubuntu Operating system 8.10 and this installing process also works with upgraded version of Ubuntu OS. For installing Py…
Strings in Python are the set of characters that, once defined, cannot be changed by any other method like replace. Even if we use the replace method it still does not modify the original string that we use, but just copies the string and then modif…
Learn the basics of modules and packages in Python. Every Python file is a module, ending in the suffix: .py: Modules are a collection of functions and variables.: Packages are a collection of modules.: Module functions and variables are accessed us…
Learn the basics of while and for loops in Python.  while loops are used for testing while, or until, a condition is met: The structure of a while loop is as follows:     while <condition>:         do something         repeate: The break statement m…

777 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question