A quick rundown of what we've learned in this chapter.
You can conditionally apply a block of Puppet code using an if statement:
if EXPRESSION {
OPTIONAL_SOMETHING
}You can add extra elsif clauses and an optional else clause:
if EXPRESSION {
OPTIONAL_SOMETHING
} elsif ANOTHER_EXPRESSION {
OPTIONAL_SOMETHING_ELSE
} else {
OPTIONAL_OTHER_THING
}The else clause, if present, will be applied if none of the conditions match.
The case statement lets you conditionally apply code if any of a number of possible cases are matched:
case EXPRESSION {
CASE1 { BLOCK1 }
CASE2 { BLOCK2 }
CASE3 { BLOCK3 }
...
default : { ... }
}With a selector, you can test a number of cases and return a value:
$result = EXPRESSION ? {
CASE1 => VALUE1,
CASE2 => VALUE2,
CASE3 => VALUE3,
default => DEFAULT_VALUE,
}