Sha256: 628aab68297114b6f83bb12f5e52d81d143e22485bf94826d2c1645f5e75e136
Contents?: true
Size: 1.72 KB
Versions: 5
Compression:
Stored size: 1.72 KB
Contents
require 'strscan'
module Kashi
class ExpansionError < StandardError
end
class SecretExpander
Literal = Struct.new(:literal)
Variable = Struct.new(:name)
def initialize(provider_name)
@provider = load_provider(provider_name)
@asked_variables = {}
end
def expand(str)
return str unless str
tokens = parse(str)
variables = Set.new
tokens.each do |token|
if token.is_a?(Variable)
unless @asked_variables.include?(token.name)
variables << token.name
end
end
end
unless variables.empty?
@provider.ask(variables).each do |k, v|
@asked_variables[k] = v
end
end
tokens.map do |token|
case token
when Literal
token.literal
when Variable
@asked_variables.fetch(token.name)
else
raise ExpansionError.new("Unknown token type: #{token.class}")
end
end.join
end
private
def parse(value)
s = StringScanner.new(value)
tokens = []
pos = 0
while s.scan_until(/\$\{(.*?)\}/)
pre = s.string.byteslice(pos...(s.pos - s.matched.size))
var = s[1]
unless pre.empty?
tokens << Literal.new(pre)
end
if var.empty?
raise ExpansionError.new('Empty interpolation is not allowed')
else
tokens << Variable.new(var)
end
pos = s.pos
end
unless s.rest.empty?
tokens << Literal.new(s.rest)
end
tokens
end
def load_provider(name)
require "kashi/secret_providers/#{name}"
Kashi::SecretProviders.const_get(name.split('_').map(&:capitalize).join('')).new
end
end
end
Version data entries
5 entries across 5 versions & 1 rubygems