Bamboo build log not in sync
Asked by Graeme Kidd:

Hi,

One of our deployment scripts uses Python which Bamboo is able to run no problem. The issue comes when the Build Log doesn't seem to record the output in the same logical order specified in the Python script.

For example when the Python script is run on the command line you might expect to see the following output:

```
sending incremental file listgraphics/images/files/support/SERVICE_NAME: apacheTYPE               : 10  WIN32_OWN_PROCESS STATE              : 1  STOPPEDWIN32_EXIT_CODE    : 0  (0x0)SERVICE_EXIT_CODE  : 0  (0x0)CHECKPOINT         : 0x0WAIT_HINT          : 0x0
```

Instead the Bamboo Build log displays the following log:

```
sending incremental file listgraphics/imaSERVICE_NAME: apacheTYPE               : 10  WIN32_OWN_PROCESS STATE              : 1  STOPPEDWIN32_EXIT_CODE    : 0  (0x0)SERVICE_EXIT_CODE  : 0  (0x0)CHECKPOINT         : 0x0WAIT_HINT          : 0x0ges/files/support/
```

Does this imply that the commands are not working in the same logical order compared to the command prompt or is it just the way Java reads the output stream?

Either way is it possible to improve the output of the log as knowing the sequence of events is an important tool in the debugging stage.

Thanks


Answers:
author: Przemek Bruski
body: Your script probably sends some of the output on stdout and the rest on stderr stream. These streams are separate, one is buffered and the other one is not. The fact that you are seeing them in certain order when you run the script on command line cannot be depended upon.

You can get the same result on command line and in Bamboo if you make the script output everything on stdout - ideally directly in the script, but if you can't, redirect the output.

comments: author: Graeme Kidd
body: Thanks for the tip which does seem possible in Python. At the moment I use one of the following commands:

```
# Basic callsubprocess.call(apache_cmd, stderr=subprocess.STDOUT)# Advanced call to record outputp = subprocess.Popen(apache_cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)stdout, stderr = p.communicate()
```

The basic call on line 2 forces all STDOUT data to be handled by the parent's file handler and all STDERR output should be captured by the same file handler as STDOUT. The same is happening on line 4 except STDOUT now goes to a new PIPE which Python can communicate with. Further explanation is given in the Python documentation:

[17.1.1.1. Frequently Used Arguments](http://docs.python.org/library/subprocess.html#frequently-used-arguments)
> *stdin* , *stdout* and *stderr* specify the executed program's standard input, standard output and standard error file handles, respectively. Valid values are [\<tt\>PIPE\</tt\>](http://docs.python.org/library/subprocess.html#subprocess.PIPE "subprocess.PIPE"), an existing file descriptor (a positive integer), an existing file object, and \<tt\>None\</tt\>. [\<tt\>PIPE\</tt\>](http://docs.python.org/library/subprocess.html#subprocess.PIPE "subprocess.PIPE") indicates that a new pipe to the child should be created. With the default settings of \<tt\>None\</tt\>, no redirection will occur; the child's file handles will be inherited from the parent. Additionally, *stderr* can be [\<tt\>STDOUT\</tt\>](http://docs.python.org/library/subprocess.html#subprocess.STDOUT "subprocess.STDOUT"), which indicates that the stderr data from the child process should be captured into the same file handle as for stdout.

Unfortunately these settings don't seem to help so unless you have any other ideas I could take this question to a more Python oriented forum.

Thanks again


author: Przemek Bruski
body: Let's start with something simple, if you change your ptyhon script call to :

python script.py 2\>\&1

does it work?


author: Graeme Kidd
body: The change has been applied in following way:
> Beginning to execute external process for build 'Test Web Deploymet'  
> ... running command line:   
> apache_deploy.py  
> --src  
> E:\\bamboo-home\\xml-data\\build-dir\\TESTDEPLOY\\web\\trunk\\build\\  
> --des  
> test-web  
> --rev  
> 169  
> --typ  
> ful  
> 2\>\&1  
> ... in: E:\\bamboo-home\\xml-data\\build-dir\\TESTDEPLOY\\web\\etc\\trunk\\scripts

Still no luck


author: Przemek Bruski
body: And if you redirect:

script.py \>logfile 2\&1

Is the file in the proper order then?


author: Graeme Kidd
body: Looks like simply outputting to a text file outside of Bamboo causes inconstancies. After looking into it further the issue was indeed due to buffering, after forcing stdin, stdout and stderr to be totally unbuffered using the --u flag: <http://docs.python.org/using/cmdline.html#cmdoption-u> the issue resolved itself.

Thanks again


author: Joshua Bouganim
body: -u did it for me. Thanks!