Versionless feature impact on featureUtility

[cbridgha]

Version-less features being proposed in Epic #25704 describe defining features by their function only without specifying a version.

featureUtility is used to interact with a specific Liberty server, and available feature repositories for installation, or querying the repository for feature details.

featureUtility has two main methods for installing features into a local Liberty install/environment:

1. Command line list of features. (./featureUtility installFeature servlet-5.0,mpHealth-4.0)
2. Command that points to a server.xml set of features (./featureUtility installServerFeatures <serverName>)

Considering 1 - installFeature today resolves and installs all tolerated dependencies of the listed features. Because it is not known the exact version of dependent features that will be required by a server in this environment.

Initially we are NOT proposing any additional support for passing in versionless features to this command, BUT in the future we could envision an additional convenience that allowed allowed versionless features to be listed like:

./featureUtility installFeature servlet,mpHealth

All available versions of each listed feature would be installed, and thus all tolerated dependencies of each would also be installed. (This would quickly create a much larger Liberty footprint...).

Considering 2 - installServerFeatures knows the complete set of features being used, and uses the normal kernel resolution code to work out what features to install.

The list of features returned by installServerFeatures, would be a "resolved" list of "versioned" features, and would not require any special handling for "version-less" features.

[cbridgha]

Closing this issue - now beeing tracked by: #28165