Class: Hako::EnvExpander
- Inherits:
-
Object
show all
- Defined in:
- lib/hako/env_expander.rb
Defined Under Namespace
Classes: ExpansionError, Literal, Variable
Instance Method Summary
collapse
Constructor Details
#initialize(providers) ⇒ EnvExpander
Returns a new instance of EnvExpander.
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# File 'lib/hako/env_expander.rb', line 17
def initialize(providers)
@providers = providers
end
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Instance Method Details
#expand(env) ⇒ Hash<String, String>
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# File 'lib/hako/env_expander.rb', line 23
def expand(env)
parsed_env = parse_env(env)
variables = Set.new
parsed_env.each_value do |tokens|
tokens.each do |t|
if t.is_a?(Variable)
variables << t.name
end
end
end
values = {}
@providers.each do |provider|
if variables.empty?
break
end
provider.ask(variables.to_a).each do |var, val|
values[var] = val
variables.delete(var)
end
end
unless variables.empty?
raise ExpansionError.new("Could not resolve embedded variables from $providers=#{@providers}: #{variables.to_a}")
end
expanded_env = {}
parsed_env.each do |key, tokens|
expanded_env[key] = tokens.map { |t| expand_value(values, t) }.join('')
end
expanded_env
end
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#expand_value(values, token) ⇒ Object
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# File 'lib/hako/env_expander.rb', line 132
def expand_value(values, token)
case token
when Literal
token.literal
when Variable
values.fetch(token.name)
else
raise ExpansionError.new("Unknown token type: #{token.class}")
end
end
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#parse(value) ⇒ Array
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# File 'lib/hako/env_expander.rb', line 108
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
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#parse_env(env) ⇒ Hash<String, Array<Literal, Variable>>
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# File 'lib/hako/env_expander.rb', line 94
def parse_env(env)
parsed_env = {}
env.each do |key, val|
unless val.is_a?(String)
raise ExpansionError.new("#{key} must be a String but got #{val.class}: #{val.inspect}")
end
parsed_env[key] = parse(val)
end
parsed_env
end
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#validate!(env) ⇒ Boolean
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# File 'lib/hako/env_expander.rb', line 58
def validate!(env)
parsed_env = parse_env(env)
variables = Set.new
parsed_env.each_value do |tokens|
tokens.each do |t|
if t.is_a?(Variable)
variables << t.name
end
end
end
@providers.each do |provider|
if variables.empty?
break
end
if provider.can_ask_keys?
provider.ask_keys(variables.to_a).each do |var|
variables.delete(var)
end
else
Hako.logger.warn("EnvProvider#validate! is skipped because #{provider.class} doesn't support ask_keys method")
return false
end
end
unless variables.empty?
raise ExpansionError.new("Could not find embedded variables from $providers=#{@providers}: #{variables.to_a}")
end
true
end
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