Tags

A tag consists of a unique name and a rule. Tags match a node if evaluating the node against the tag's facts results in true. Tag matching is case sensitive.

For example, to create a tag, small, that matches any machine with less than 4GB of memory:
    razor create-tag --name small
      --rule '["<", ["num", ["fact", "memorysize_mb"]], 4128]'

Tag rules

Rule expressions are of the form op arg1 arg2 ... argn] where op is one of the accepted [operators, and arg1 through argn are the arguments for the operator. If the arguments are expressions themselves, they're evaluated before op.

Here are some example tag rules:
  • To match nodes with more than 10 processors: [">", ["num", ["fact", "processorcount"]], 10]

  • To match nodes with specified MAC addresses: ["has_macaddress", "de:ea:db:ee:f0:00", "de:ea:db:ee:f0:01"]

Tag operators

The expression language supports these operators:
Operator Returns Aliases
["=", arg1, arg2] True if the specified arguments are equal. "eq"
["!=", arg1, arg2] True if the specified arguments are not equal. "neq"
["and", arg1, ..., argn] True if all arguments are true.
["or", arg1, ..., argn] True if any argument is true.
["not", arg] True if the argument evaluates to false or nil.
["fact", arg1 (, arg2)] The arg1 fact for the node. The optional arg2 is used if the arg1 fact isn't present.
["metadata", arg1 (, arg2)] The arg metadata entry for the node. The optional arg2 is used if the arg1 fact isn't present.
["tag", arg] True if the node has the specified tag.
["has_macaddress", arg1, arg2 ..., argn] True if any facts that start with "macaddress" matches one of arg1 ... argn.
["has_macaddress_like", arg1, arg2 ..., argn] True if the hardware MAC address matches one of arg1 ... argn as regular expressions.
["in", arg1, arg2, ..., argn] True if arg1 matches one of arg2 ... argn.
["num", arg1] arg1 as a numeric value, or raises an error.
[">", arg1, arg2] True if arg1 is greater than arg2. "gt"
["<", arg1, arg2] True if arg1 is less than arg2. "lt"
[">=", arg1, arg2] True if arg1 is greater than or equal to arg2. "gte"
["<=", arg1, arg2] True if arg1 is less than or equal to arg2. "lte"
["like", arg1, arg2] True if arg1 matches the pattern of arg2, interpreted as a regular expression.
["lower", arg] The lowercase version of the string arg.
["upper", arg] The uppercase version of the string arg.