Obnam configuration files and settings

This chapter discusses Obnam configuration files: where they are, what they contain, and how they are used.

Where is my configuration?

Obnam looks for its configuration files in a number of places:

Note that in /etc/obnam and ~/.config/obnam, all files that have a .conf suffix are loaded, in "asciibetical" order, which is like alphabetical, but based on character codes rather than what humans understand, but unlike alphabetical isn't dependent on the language being used.

Any files in the list above may or may not exist. If it exists, it is read, and then the next file is read. A setting in one file can be overridden by a later file, if it is set there as well. For example, /etc/obnam.conf might set log-level to INFO, but ~/.obnam.conf may then set it to DEBUG, if a user wants more detailed log files.

The Obnam configuration files in /etc apply to everyone who runs Obnam on that machine. This is important: they are not just for when root runs Obnam.

If you want to have several Obnam configurations, for example for different backup repositories, you need to name or place the files so they aren't on the list above. For example:

You would then need to specify that file for Obnam to use it:

obnam --config ~/.config/obnam/usbdrive.profile`

If you want to not be affected by any configuration files, except the ones you specify explicitly, you need to also use the --no-default-config option:

obnam --no-default-config --config ~/.obnam-is-fun.conf

Command line options override values from configuration files.

Configuration file syntax

Obnam configuration files use the INI file syntax, specifically the variant implemented by the Python ConfigParser library. They look like this:

[config]
log-level = debug
log = /var/log/obnam.log
encrypt-with = CAFEBEEF
root = /
one-file-system = yes

Names of configuration variables are the same as the corresponding command line options. If --foo is the option, then the variable in the file is foo. Any command line option --foo=bar can be used in a configuration file as foo = bar. There's are exceptions to this (--no-default-config, --config, --help, and a few others), but they're all things you wouldn't put in a configuration file anyway.

Every option, or setting, has a type. Mostly this doesn't matter, unless you give it a value that isn't suitable. The two important exceptions to this are:

For a more detailed explanation of Obnam configuration file syntax, see the cliapp(5) manual page on your system, or cliapp man page on the WWW.

Checking what my configuration is

Obnam can read configuration files from a number of places, and it can be tricky to figure out what the actual configuration is. The --dump-config option helps here.

obnam --config ~/.obnam.fun --exclude-caches --dump-config

The option will tell Obnam to write out (to the standard output) a configuration file that captures every setting, and reporting the value that it would have if --dump-config weren't used.

This is a good way to see what the current settings are and also as a starting point if you want to make a configuration file from scratch.

Finding out all the configuration settings

This manual does not yet have a list of all the settings, and their explanation. Obnam provides built-in help (run obnam --help) and a manual page automatically generated from the built-in help (run man obnam or see obnam man page). Some day, this chapter will include an automatically generated section that explains each setting. Until then, you're free to point fingers at Obnam's author and giggle at his laziness.