It's often necessary to pass passwords to commands on the slave, but it's no
fun to see those passwords appear for everyone else in the build log. The
Obfuscated class can help here. Instantiate it with a real string and a
fake string that should appear in logfiles. You can then use the
Obfuscated.get_real and Obfuscated.get_fake static methods to
convert a list of command words to the real or fake equivalent.
The RunProcess implementation in the buildslave will apply these methods
automatically, so just feed it a list of strings and Obfuscated objects.