reclass to-do list

Common set of classes

A lot of the classes I have set up during the various stages of development of reclass are generic. It would probably be sensible to make them available as part of reclass, to give people a common baseline to work from, and to ensure a certain level of consistency between users.

This could also provide a more realistic example to users on how to use reclass.

Testing framework

There is rudimentary testing in place, but it’s inconsistent. I got side-tracked into discussions about the philosphy of mocking objects. This could all be fixed and unified.

Also, storage, outputters, CLI and adapters have absolutely no tests yet…

The testing framework should also incorporate the example classes mentioned above.

Configurable file extension

Right now, .yml is hard-coded. This could be exported to the configuration file, or even given as a list, so that .yml and .yaml can both be used.

Actually, I don’t think this is such a good idea. If we create too many options right now, it’ll be harder to unify later. Please also see `issue #17 <`_ for a discussion about this.

Verbosity, debugging

Verbose output and debug logging would be a very useful addition to help people understand what’s going on, where data are being changed/merged, and to help solve problems.

Data from CMS for interpolation

Depending on the CMS in question, it would be nice if reclass had access to the host-specific data (facts, grains, etc.) and could use those in parameter interpolation. I can imagine this working for Salt, where the grains dictionary (and results from previous external node classifiers) is made available to the external node classifiers, but I am not convinced this will be possible in Ansible and Puppet.

On the other hand, providing CMS-specific data to reclass will make people depend on it, meaning Salt cannot be used with multiple tools anymore.

The way to deal with that would be to map grains, facts, whatever the CMS calls them, to a shared naming scheme/taxonomy, but that’s a painful task, I think. It would mean, however, that even templates could be shared between CMSs if they only use the data provided by reclass (i.e. grains/facts become pillar data).

Membership information

It would be nice if reclass could provide e.g. the Nagios master node with a list of clients that define it as their master. That would short-circuit Puppet’s storeconfigs and Salt’s mine.

The way I envision this currently is to provide something I call “inventory queries”. For instance, the Nagios master node’s reclass data would contain the following ($[…] would denote interpolation to create a list, a bit like list comprehension):

    hosts: $[nagios:master == SELF.nodename]

This would cause reclass to iterate the inventory and generate a list of all the nodes that define a parameter nagios:master whose value equals to the name of the current node.

This could be greatly simplified. For instance, we could simply limit comparisons against the name of the current node and just specify


which would be expanded to a list of node names whose pillar data includes ${nagios:master} that matches the current node’s name.

Or it could be made arbitrarily complex and flexible, e.g. any of the following:

$[nagios:master == SELF.nodename]                  # replace with nodename
$[nagios:master == SELF.nodename | nodename]       # name replacement value
$[nagios:master == SELF.nodename | nagios:nodeid]  # replace with pillar data
$[x:nagios:nodeid foreach x | x:nagios:master == SELF.nodename]

I’d rather not code this up from scratch, so I am looking for ideas for reuse…

Configuration file lookup improvements

Right now, the adapters and the CLI look for the configuration file in a fixed set of locations. On of those derives from OPT_INVENTORY_BASE_URI, the default inventory base URI (/etc/reclass). This should probably be updated in case the user changes the URI.

Furthermore, $CWD and ~ might not make a lot of sense in all use-cases.

However, this might be better addressed by the following point:

Adapter class hierarchy

At the moment, adapters are just imperative code. It might make more sense to wrap them in classes, which customise things like command-line and config file parsing.

One nice way would be to generalise configuration file reading, integrate it with command-line parsing, and then allow the consumers (the adapters) to configure them, for instance, in the Salt adapter:

config_proxy = ConfigProxy()
config_proxy.set_configfile_search_path(['/etc/reclass', '/etc/salt'])
config_proxy.lock_config_option('output', 'yaml')

The last call would effectively remove the --output config option from the CLI, and yield an error (or warning) if the option was encountered while parsing the configuration file.

Furthermore, the class instances could become long-lived and keep a reference to a storage proxy, e.g. to prevent having to reload storage on every request.

Node lists

Class mappings are still experimental, and one of the reasons I am not too happy with them right now is that one would still need to provide node files for all nodes for inventory invocations. This is because class mappings can assign classes based on patterns or regular expressions, but it is not possible to turn a pattern or regular expression into a list of valid nodes.

Issue #9 contains a lengthy discussion on this. At the moment, I am unsure what the best way forward is.

Inventory filters

As described in issue #11: provide a means to limit the enumeration of the inventory, according to node name patterns, or using classes white-/blacklists.