---
date: 2014-01-24
TItle: NFS with Puppet and an ENC
category: devops
Thumbnails: https://puppetlabs.com/sites/default/files/PL_logo_horizontal_RGB_0.svg
---

Ages ago (it seems) I posted a
[howto](https://www.chriscowley.me.uk/blog/2013/04/11/using-hiera-with-puppet/)
on configure NFS using Puppet and Hiera. I have been using this happily
for several months and adding a new share was is as simple as adding a
line to a YAML file. I was never completely happy with it though,
especially after I decided to deploy [The
Foreman](https://www.theforeman.org) in my lab.

The reason I was never satisfied is because The Foreman makes a really
good ENC. I wanted to use this, so I have modified my module to use an
ENC rather than Hiera directly.

OK, first I we need to get the module into a position where it uses
parameterized classes. This is actually quite simple.

My original manifest is
[here](https://github.com/chriscowley/chriscowley-nfs/blob/b5d5fe6eba75379fad37255ceddb55208cbe7208/manifests/server.pp).
The key item is the *\$exports* variable, which is hiera data. All I did
was create a class parameter called *exports* and removed the variable
within the class. You can see the new code
[here](https://github.com/chriscowley/chriscowley-nfs/blob/ab9627cf920f3a87986aa7379168572ca3a55f7e/manifests/server.pp).
I have also moved the `list_exports` function out into a [seperate
file](https://github.com/chriscowley/chriscowley-nfs/blob/ab9627cf920f3a87986aa7379168572ca3a55f7e/manifests/list_exports.pp).
Apparently this makes it more readable, although I am not convinced in
this instance.

I also took the chance to update my module a bit so that it was not
hard-coded to my own lab network. To that end, it will automatically
pull out the IP address and netmask of eth0. You can edit this easily
enough using your ENC.

`manifests/server.pp   class nfs::server (     $exports = [ '/srv/share'],     $networkallowed = $::network_eth0,     $netmaskallowed = $::netmask_eth0,   ) {     // Code here   }`

Next we need a simple ENC to supply the data. An ENC is actually just
any script that returns YAML. It has a single parameter, which is the
FQDN of the node. I use this:

    #!/bin/bash
    DATADIR="/var/local/enc"
    NODE=$1

    cat "${DATADIR}/${NODE}.yaml"

Next you need a YAML file that looks like:

    ---
    environment: production
    classes:
      nfs::server:
        exports:
          - /srv/share1
          - /srv/share3
        networkallowed: 192.168.0.0
        netmaskallowed: 255.255.255.0
    parameters:

Finally, you need to enable this on your Puppet master. Add this to
`/etc/puppet/puppet.conf`:

    [master]
        node_terminus = exec
        external_nodes = /usr/local/bin/simple-enc.sh

Now whenever a node with the FQDN nfs.example.lan syncs with the master
it runs `/usr/local/bin/simple-enc.sh nfs.examle.lan.yaml`. This returns
the contents of the YAML file above. The layout of it is pretty logical,
but I suggest reading Puppetlabs
[docs](https://docs.puppetlabs.com/guides/external_nodes.html).

How is this better than the previous Hiera setup? First I can now use my
module with The Foreman which answers my immediate need. Second I can
now submit this module to the Forge with a warm fuzzy feeling inside as
I am a good citizen. not only does it work with Puppet 3, but also
really old versions of Puppet that do not support an ENC or Hiera. It
can do this because the user can still edit the class parameters
directly, or set the in `site.pp` (**DON\'T DO THAT**).

You can install the module on your own Puppet master with:

    git clone https://gitlab.chriscowley.me.uk/puppet/chriscowley-nfs.git \
        /etc/puppet/modules/nfs/