Question

Caution

Buildbot no longer supports Python 2.7 on the Buildbot master.

2.5.12.49. SetPropertyFromCommand

class buildbot.steps.shell.SetPropertyFromCommand

This buildstep is similar to ShellCommand, except that it captures the output of the command into a property. It is usually used like this:

from buildbot.plugins import steps

f.addStep(steps.SetPropertyFromCommand(command="uname -a", property="uname"))

This runs uname -a and captures its stdout, stripped of leading and trailing whitespace, in the property uname. To avoid stripping, add strip=False.

The property argument can be specified as an Interpolate object, allowing the property name to be built from other property values.

Passing includeStdout=False (defaults to True) stops capture from stdout.

Passing includeStderr=True (defaults to False) allows capture from stderr.

The more advanced usage allows you to specify a function to extract properties from the command output. Here you can use regular expressions, string interpolation, or whatever you would like. In this form, extract_fn should be passed, and not Property. The extract_fn function is called with three arguments: the exit status of the command, its standard output as a string, and its standard error as a string. It should return a dictionary containing all new properties.

Note that passing in extract_fn will set includeStderr to True.

def glob2list(rc, stdout, stderr):
    jpgs = [l.strip() for l in stdout.split('\n')]
    return {'jpgs': jpgs}

f.addStep(SetPropertyFromCommand(command="ls -1 *.jpg", extract_fn=glob2list))

Note that any ordering relationship of the contents of stdout and stderr is lost. For example, given:

f.addStep(SetPropertyFromCommand(
    command="echo output1; echo error >&2; echo output2",
    extract_fn=my_extract))

Then my_extract will see stdout="output1\noutput2\n" and stderr="error\n".

Avoid using the extract_fn form of this step with commands that produce a great deal of output, as the output is buffered in memory until complete.