Pandoradep

pandoradep is a python tool to manage PANDORA's dependencies. It is a standalone tool and can be found here. You can install it either from source or using pip. For instructions refer to the README.

Rationale

The need for a tool to manage our dependencies, declared in each package's package.xml file, led us to the development of pandoradep. Natively, ROS can resolve and install debian dependencies using rosdep. In order to resolve non-debian dependencies (from source) there are rosinstall and wstool which, when combined, can fetch the appropriate dependencies in order to build a package from source.

So, pandoradep is a tool that is capable of scanning one or multiple packages and according to their declared dependencies (in the package.xml) can create an appropriate rosinstall file in order to be used later by wstool.

In order to know where to find each dependency, it needs to keep track of every PANDORA repo and the packages that contains. That information is available through this YAML file. That file gets updated every time we sync our private repos with our public one (when someone pushes to our stable branch hydro-devel, Jenkins manages the sync).

Usage

The case that we cover here is that we have already fetched a repo that we are interested in and we now want to build it. In order to build it, aside from other dependencies we need to fetch other PANDORA repos that this package depends on. In our example we want to build the vision package.

NOTE: A more detailed guide on how to fetch and compile our packages can be found [here](Setup Packages). This is a guide on how to use pandoradep.

First we create a workspace:

$ mkdir -p ~/pandora_ws/src
$ cd ~/pandora_ws/src
$ wstool init .

Then we clone the repo that contains PANDORA's vision packages:

$ git clone git@github.com:pandora-auth-ros-pkg/pandora_vision.git

Now we are going to use pandoradep in order to fetch dependencies:

$ pandoradep scan . > deps.rosinstall
$ wstool merge deps.rosinstall
$ wstool update

The command pandoradep scan will output the dependencies to stdout, in a rosintall friendly format. In our case we will get something like:

- git: {local-name: pandora_vision, uri: 'git@github.com:pandora-auth-ros-pkg/pandora_vision.git', version: hydro-devel}
- git: {local-name: pandora_common, uri: 'git@github.com:pandora-auth-ros-pkg/pandora_common.git', version: hydro-devel}

Since we would like to use wstool in order to fetch the appropriate repos, we are writing the output of pandoradep to a file, in order to use it later with wstool.

We need to install debian dependencies as well, in order to be able to compile the packages:

$ cd ..
$ rosdep install --from-paths src --ignore-src --rosdistro $ROS_DISTRO

Finally, we are ready to compile our code:

$ catkin_make

If we need, in the future to fetch updates from our dependencies, we can run in ~/pandora_ws/src:

$ wstool update

Relying on a different branch

Lets say that we have made some fixes in the state_manager package that also affect vision packages. In order to test the changes before releasing them we have created a branch named fix-this in both pandora_vision and pandora_common repos. Now we have to change the package.xml of each package that depends on pandora_common like so:

...
<buildtool_depend>catkin</buildtool_depend>

<build_depend>roscpp</build_depend>
<build_depend>cv_bridge</build_depend>
<build_depend>image_transport</build_depend>
<build_depend>sensor_msgs</build_depend>
<build_depend>pandora_vision_msgs</build_depend>
<build_depend version_eq="fix-this">state_manager</build_depend>
<build_depend>state_manager_msgs</build_depend>
<build_depend>dynamic_reconfigure</build_depend>
...

The above, is a way to notify pandoradep that we need the state_manager package, but we need the version that resides in the fix-this branch. This is very useful for our Continuous Integration schema, as it can test branches different than hydro-devel. Because it is not very helpful when we are working in out PC (since we are only cloning packages once), we should not forget to remove the version_eq tag when the fix-this branch has been merged to hydro-devel.

Command line usage

For complete command line reference you can type pandoradep --help:

Usage: pandoradep [OPTIONS] COMMAND [ARGS]...

  A tiny cli tool to manage PANDORA's dependencies.

Options:
  --version  Return the current version.
  --help     Show this message and exit.

Commands:
  create  Creates a repos.yml file, mapping each package to the corresponding repo. [used by CI]
  scan    Scans the directory tree for dependencies.
  update  Updates dependencies [used by CI]