On Aug 30, 9:15 am, M C <mcsof...@gmail.com> wrote: > Hi, > > is it possible to push a file (with "source" or "content") and then add > lines without having Puppet to regenerate it every time it runs? > And, how can I add, remove or alter text lines without keeping old contents?
As I understand you, you want Puppet to provide a default version of the file in the event that it does not exist at all, but otherwise to leave it completely alone. That runs against the Puppet grain: it would be better to completely manage the file content, updating the node's manifests as appropriate when you want the file's contents to change. Nevertheless, you can do this with Puppet, though it requires a bit more work (note: that's a sign that you're trying to work against the tool). You can hack it together as an Exec resource, and that may be the most reliable way to go, but I'm going to show you how you can build this around a File resource. Using a File may be advantageous when the default file contents are lengthy or sensitive, but mainly Files just aren't Execs. The best way might be to derive a custom type from File that provides the behavior you want, but I'm not going there today. The first thing to understand is that File's 'source' and 'content' properties always specify the exact file contents. If we're going to use them then we have to put in some kind of conditional logic. For your specific request, that conditional logic needs to be based on the presence or absence of the target file. Conditional logic is evaluated on the master, so the master needs to know during catalog compilation whether the target file already exists, and that requires a custom fact (see http://docs.puppetlabs.com/guides/custom_facts.html). The Ruby code for this particular fact can probably be something similar to this: Facter.add('myconf_exists') do setcode do File.exists?('/etc/myconf') ? 'true' : 'false' end end Your manifest using this fact might then contain something like this: file { '/etc/myconf': ensure => file, content => $::myconf_exists ? { 'true' => undef, default => '... contents ...' } # other properties ... } Note that when formulated as above, any properties other than content (e.g. owner, permissions) will be ensured on every run. If you want more than one property to be conditional, then you would probably be better off wrapping the while resource declaration in an 'if' construct. Note also that there is a hidden potential gotcha here: the presence of the file is determined when Puppet requests the catalog, not when it applies it. If the file is created in between then Puppet will replace it. Furthermore, if Puppet ever cannot retrieve a fresh catalog from the master, then its cached one may be stale with respect to whether the target file actually exists; that potentially extends the window in which file creation might be overlooked. > Note: i want resources to be executed only if something actually changes. Depending on how you look at it, that's either always or never what Puppet does. That is, Puppet always checks each declared resource to determine whether its actual state matches its declared target state, so if you're saying you don't want that then Puppet is not the tool for you. On the other hand, Puppet only modifies resources that it finds out of sync with their declarations, and I think that's what you're asking for. John -- You received this message because you are subscribed to the Google Groups "Puppet Users" group. To post to this group, send email to puppet-users@googlegroups.com. To unsubscribe from this group, send email to puppet-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/puppet-users?hl=en.
