Choose which Ignition collection to invoke from command line

[osrf-migration]

Original report (archived issue) by Louise Poubel (Bitbucket: chapulina, GitHub: chapulina).

---

Summary

Ignition Tools allows us to have multiple versions of a library installed and usable side-by-side. But picking the versions could be made simpler if this package understood the concept of Ignition collections (acropolis, blueprint, citadel, etc...).

Motivation

Right now, the user can check all the versions available for a specific library with --versions, then pick which one to use with --force-version. Since each command comes from a different library, and each library has a different version on a given collection, it's inconvenient to remember or check the version for all individual commands.

For example, to use Citadel commands:

ign topic --force-version 8.0.0 ...
ign gui --force-version 3.0.0 ...
ign msgs --force-version 5.1.0 ...

It would be much more convenient to do something like this:

ign topic --citadel ...
ign gui --citadel ...
ign msgs --citadel ...

Describe alternatives you've considered

Something like this would need to be implemented at the ign-tools level, because it requires knowledge of all different versions for a library. But we may not want to hardcode the concept of collections in here, in case we want to support libraries which are not part of a collection.

One way I can think of implementing this would be to have aliases between versions and collections. When a user installs the igntion-citadel package, that package could install the list of aliases. This way, neither ign-tools nor the individual libraries need to know about collections.

[osrf-migration]

Original comment by Louise Poubel (Bitbucket: chapulina, GitHub: chapulina).

---

• Edited issue description

[chapulina]

Something like this would need to be implemented at the ign-tools level, because it requires knowledge of all different versions for a library.

Actually I think this could be accomplished using the metapackages that we have for each collection (i.e. https://github.com/ignitionrobotics/ign-edifice/), because that knows about all the versions that go into a release.