PyBOMBS

Minimum Python version: 2.7

License

This file is part of PyBOMBS

PyBOMBS is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

PyBOMBS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with PyBOMBS; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Boston, MA 02110-1301, USA.

Installation

PyBOMBS can be installed using Python's setuptools. From the top level of the source code repository, run

$ python setup.py build

$ sudo python setup.py install

This will install PyBOMBS and all required dependencies. See

$ python setup.py build --help
$ python setup.py install --help

for additional settings.

For development purposes, it's possible to run PyBOMBS without installation. Simply run pybombs/main.py and make sure pybombs/ is in reach. pip also provides a -e switch for installing PyBOMBS in 'editable' mode.

Quickstart

For the impatient:

Install PyBOMBS as per the previous section
Add a list of recipes, e.g. by running

$ pybombs recipes add gnuradio https://github.com/gnuradio/recipes2.git $ # Note: This URL will likely change soon.
Create a prefix (a place to store your local installation):

$ pybombs prefix init /path/to/prefix -a myprefix
Start installing:

$ pybombs -p myprefix install gnuradio gr-osmosdr
Optional: Make your prefix the default (this will save you having to type -p myprefix):

$ pybombs config default_prefix myprefix

Prefixes

A prefix is a directory into which packages are installed. The prefix may be /usr/local/ for system-wide installation of packages, or something like ~/src/prefix if you want to have a user-level, local installation path. The latter is highly recommended for local development, as it allows compilation and installation without root access. Any directory may be a prefix, but it is highly recommended to choose a dedicated directory for this purpose.

Prefixes require a configuration directory to function properly. Typically, it is called .pybombs/ and is a subdirectory of the prefix. So, if your prefix is ~/src/prefix, there will be a directory called ~/src/prefix/.pybombs/ containing special files. The two most important files are the inventory file (inventory.yml) and the prefix-local configuration file (config.yml), but it can also contain recipe files that are specific to this prefix.

There is no limit to the number of prefixes. Indeed, it may make sense to have multiple prefixes, e.g. one for system-wide installation, one for a user-specific installation, and one for cross-compiling to a different platform.

Initializing Prefixes

Any directory can function as a prefix, and PyBOMBS will make sure all the required files and directories are created. However, PyBOMBS provides a way to initialize a directory to be a full PyBOMBS prefix:

$ pybombs prefix init /path/to/prefix [-a alias]

This is similar to git init. The optional alias allows you to access the prefix with the alias instead of the full path.

Aliases

In order to make prefix selection more easy, it is possible to assign names to prefixes by adding a [prefix_aliases] section to a configuration file. The format is alias=/path/to/prefix. Instead of providing the entire path every time, the alias can be used instead. When running pybombs prefix init, you can use the --alias argument to set this automatically.

Prefix Selection

Prefixes are selected by the following rules, in this order:

Whatever is provided by the -p or --prefix command line switch
The current directory
The default prefix as defined by the default_prefix config switch

If no prefix can be found, most PyBOMBS operations will not be possible, but some will still work.

Configuring a prefix' environment (e.g. for cross-compiling)

Setting environment variables directly:

In any config file that is read, a env: section can be added. This will set environment variables for any command (configure, build, make...) that is run within PyBOMBS.

Note that this will still use the regular system environment as well, but it will overwrite existing variables. Variable expansion can be used, so this will keep the original setting:

env:
    LD_LIBRARY_PATH: ${LD_LIBRARY_PATH}:/path/to/more/libs

Note: Because this is a YAML file, remember to separate key/value pairs with colon (:), not an equals sign, as you would in a shell script.

In all cases, the environment variable PYBOMBS_PREFIX is set to the current prefix, and PYBOMBS_PREFIX_SRC is set to the source directory.

Using an external script to set the environment

Inside the config section, a shell script can be defined that sets up an environment, which will then be used for commands running inside this prefix.

Example:

config:
    # Other vars
    setup_env: /path/to/environment-setup-armv7ahf-vfp-neon-oe-linux-gnueabi

Recipes

Recipe Format

Recipes files are in YAML format. To write new recipes, the easiest way is to use other recipes as examples.

Important keys in the recipe files include:

inherit: This will load the values from a template file (*.lwt) before using the values from the recipe, to set up suitable defaults.
category: Can technically be anything, but certain categories carry certain meanings

Recipe Management

Recipes can be stored in multiple locations, which easily allows to store separate recipe lists for specific projects.

If the same recipe can be found in more than one location, it will be chosen from the most specific. The precise order is:

Recipe locations specified on the command line (Using the -r switch)
From the environment variable PYBOMBS_RECIPE_DIR
The current prefix (if available)
Global recipe locations

This mechanism can be used to override recipes for certain prefixes. For example, the gnuradio.lwr file could be copied and adapted to use a different branch than the default recipe does. (Note that specific parts of recipes can also be overridden in the config.yml file, in the [packages] section).

Recipe management can be mostly done through the command line using the pybombs recipes command -- editing configuration files is possible, but often not necessary. Run

$ pybombs help recipes

for further information on the pybombs recipes command.

Remote and Local Recipe Locations

Recipe locations can be either local directories (in this case, PyBOMBS will simply read any .lwr file from this directory, without traversing into subdirectories), or a remote location. Remote locations can be:

git repositories
Remotely stored .tar.gz archives

Remote locations are copied into a local directory, so PyBOMBS can read the .lwr files locally. During normal operations, PyBOMBS will not try to read the remote location, so offline usage is still possible. This local cache of recipes is stored in the same directory as the location of the corresponding config file (e.g., if ~/.pybombs/config.yml declares a recipe called 'myrecipes', the local cache will be in ~/.pybombs/recipes/myrecipes).

Configuration Files

Typically, there are four ways to configure PyBOMBS:

The global configuration file (e.g. /etc/pybombs/config.yml)
The user-local configuration file (e.g. ~/.pybombs/config.yml)
The prefix-local configuration file (e.g. ~/src/prefix/.pybombs/config.yml)
By using the --config switch on the command line

Higher numbers mean higher priority. Conflicting options are resolved by choosing option values with higher priority.

`config.yml` File Format

The config.yml files are in YAML format. A typical file looks like this:

# All configuration options:
# (Run `pybombs config` to learn which options are recognized)
config:
	satisfy_order: native,src
	default_prefix: default
	# ... more options

# Prefix aliases:
prefix_aliases:
	default: /home/user/src/pb-prefix/
	sys: /usr/local

# Prefix configuration directories:
prefix_config_dir:
	sys: /home/user/pb-default/
	# Typically, you don't need this, because the prefix configuration
	# directory is in <PREFIX>/.pybombs

# Recipe locations:
recipes:
	myrecipes: /usr/local/share/recipes
	morerecipes: /home/user/pb-recipes
	remoterecipes: git+git://url/to/repo

# Package flags:
packages:
	gnuradio:
		forcebuild: True # This will skip any packagers for this package
                                 # and use a source build
                forceinstalled: False # 'True' will always assume this package is
                                      # installed and skip installing it
                # Any other option here will override whatever's in the
                # corresponding recipe (in this case, gnuradio.lwr)

# Like package flags, but applies flags to all packages
# in a certain category. 'common' is all OOTs.
categories:
	common:
		forcebuild: True # This would force source builds for any package in the
                                 # `common` category

# Environment variables
env:
	LD_LIBRARY_PATH: ${LD_LIBRARY_PATH}:/path/to/more/libs

n-west/pybombs2