trycatch

This is a simple Puppet module that adds the functions try and catch. They can be used to catch an exception raised in the block passed to try.

This module uses the V4 function API, so you need Puppet 4.x to use it or Puppet 3.7.x with the future parser.

Example

$ret = try() || {
  assert_type('String', 1)
  notice('This code is never reached')
  'return value from try'
}.catch |$exception| {
  notice($exception['class'])
  notice($exception['message'])
  'return value from catch'
}
notice($ret)

Output:

Notice: Scope(Class[main]): Puppet::PreformattedError
Notice: Scope(Class[main]): Evaluation Error: Error while evaluating a Function Call, assert_type(): Expected type String does not match actual: Integer at /Users/dalen/src/puppet-trycatch/test.pp:2:3
Notice: Scope(Class[main]): return value from catch
Notice: Compiled catalog for river.local in environment production in 0.28 seconds
Notice: Applied catalog in 0.01 seconds

Only catch certain exceptions

try() || {
  assert_type('String', 1)
}.catch('ArgumentError', 'RuntimeError') |$exception| {
  notice("Caught ${$exception['class']}")
}

Output:

Error: Evaluation Error: Error while evaluating a Function Call, assert_type(): Expected type String does not match actual: Integer at /Users/dalen/src/puppet-trycatch/test.pp:2:3 on node river.local

Note that this doesn't take exception subclasses into account. It only checks if the class names match exactly.

Note that this is a hack, use accordingly