Puppet Function: redisget

Defined in:
lib/puppet/parser/functions/redisget.rb
Function type:
Ruby 3.x API

Overview

redisget(String $redis_key, String $redis_uri, String $default_value) ⇒ String

Returns the value of the key being looked up or nil if the key does not exist. Takes two arguments with an optional third. The first being a string value of the key to be looked up, the second is the URL to the Redis service and the third optional argument is a default value to be used if the lookup fails.

Examples:

Calling the function.

$version = redisget('version.myapp', 'redis://redis.example.com:6379')

Calling the function with a default if failure occurs

$version = redisget('version.myapp', 'redis://redis.example.com:6379', $::myapp_version)

Parameters:

  • redis_key (String) —

    The key to look up in redis.

  • redis_uri (String) —

    The endpoint of the Redis instance.

  • default_value (String) —

    The value to return if the key is not found or the connection to Redis fails

Returns:

  • (String) —

    The value of the key from redis

  • (String) —

    An empty string eg. ‘”`



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# File 'lib/puppet/parser/functions/redisget.rb', line 4

newfunction(:redisget, :type => :rvalue, :doc => <<-DOC
Returns the value of the key being looked up or nil if the key does not
exist. Takes two arguments with an optional third. The first being a string
value of the key to be looked up, the second is the URL to the Redis service
and the third optional argument is a default value to be used if the lookup
fails.
@param redis_key [String] The key to look up in redis.
@param redis_uri [String] The endpoint of the Redis instance.
@param default_value [String] The value to return if the key is not found or
the connection to Redis fails
@return [String] The value of the key from redis
@return [String] An empty string eg. `''`
@example Calling the function.
$version = redisget('version.myapp', 'redis://redis.example.com:6379')
@example Calling the function with a default if failure occurs
$version = redisget('version.myapp', 'redis://redis.example.com:6379', $::myapp_version)
DOC
) do |args|

  raise(Puppet::ParseError, "redisget(): Wrong number of arguments given (#{args.size} for 2 or 3)") if args.size != 2 and args.size != 3

  key = args[0]
  url = args[1]

  if args.size == 3
    default = args[2]
    raise(Puppet::ParseError, "redisget(): Wrong argument type given (#{default.class} for String) for arg3 (default)") if default.is_a?(String) == false
  end

  raise(Puppet::ParseError, "redisget(): Wrong argument type given (#{key.class} for String) for arg1 (key)") if key.is_a?(String) == false
  raise(Puppet::ParseError, "redisget(): Wrong argument type given (#{url.class} for String) for arg2 (url)") if url.is_a?(String) == false

  begin
    Redis.new(:url => url).get(key) || default
  rescue Redis::CannotConnectError, SocketError => e
    raise Puppet::Error, "connection to redis server failed - #{e}" unless default
    debug "Connection to redis failed with #{e} - Returning default value of #{default}"
    default
  end

end