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Initial public release of Puppet configs
author IBBoard <dev@ibboard.co.uk>
date Sat, 16 Aug 2014 19:47:38 +0000
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956e484adc12 Initial public release of Puppet configs
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1 Puppet Specific Facts
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2 =====================
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3
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4 Facter is meant to stand alone and apart from Puppet. However, Facter often
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5 runs inside Puppet and all custom facts included in the stdlib module will
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6 almost always be evaluated in the context of Puppet and Facter working
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7 together.
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8
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9 Still, we don't want to write custom facts that blow up in the users face if
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10 Puppet is not loaded in memory. This is often the case if the user runs
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11 `facter` without also supplying the `--puppet` flag.
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13 Ah! But Jeff, the custom fact won't be in the `$LOAD_PATH` unless the user
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14 supplies `--facter`! You might say...
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16 Not (always) true I say! If the user happens to have a CWD of
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17 `<modulepath>/stdlib/lib` then the facts will automatically be evaluated and
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18 blow up.
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19
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20 In any event, it's pretty easy to write a fact that has no value if Puppet is
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21 not loaded. Simply do it like this:
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23 Facter.add(:node_vardir) do
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24 setcode do
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25 # This will be nil if Puppet is not available.
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26 Facter::Util::PuppetSettings.with_puppet do
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27 Puppet[:vardir]
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28 end
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29 end
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30 end
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32 The `Facter::Util::PuppetSettings.with_puppet` method accepts a block and
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33 yields to it only if the Puppet library is loaded. If the Puppet library is
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34 not loaded, then the method silently returns `nil` which Facter interprets as
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35 an undefined fact value. The net effect is that the fact won't be set.