Implement a framework for more flexible rule configuration and matching,
mimicking the MatchExpressions pattern from K8s nodeselector.
The basic building block is MatchExpression which contains an operator
and a list of values. The operator specifies that "function" that is
applied when evaluating a given input agains the list of values.
Available operators are:
- MatchIn
- MatchNotIn
- MatchInRegexp
- MatchExists
- MatchDoesNotExist
- MatchGt
- MatchLt
- MatchIsTrue
- MatchIsFalse
Another building block of the framework is MatchExpressionSet which is a
map of string-MatchExpression pairs. It is a helper for specifying
multiple expressions that can be matched against a set of set of
features.
This patch converts all existing custom rules to utilize the new
expression-based framework.
- Implement the 'custom' feature source utilizing the
match rules implemented in previous commit.
- Add a static custom feature list for:
1. rdma.capable - marks a node where devices that support
RDMA are present.
2. rdma.enabled - marks a node where rdma modules have
been loaded.
A user may extend these features with additional match rules via
NFD configuration file.
