parameter validation

[stevendborrelli]

I don't know if this should be a macro, but I was bitten today in Ansible because interpolations resulted in an empty variable. Is it possible that we have some checks to make sure computed variables or outputs of a module meet certain conditions?

Ignore the crappy syntax, but something like:

required {
       len(computed_var) > 0
       len(consul_servers_group) = len (control_servers_group)
       len(counsul_servers_group) >= 3
               "A minimum of 3 consul servers is required)
} 

warn {
        (consul_servers_group % 2) != 0 :
               "The number of consul servers should be an odd number"
}

[stevendborrelli]

Maybe this is part of the param definition, so that it can be used outside for API's & UI rendering.

[rebeccaskinner]

I like the idea of maybe having a ‘constraint’ type option for params:

param “foo” { default = 5 constraints { type = number value > 0 } }

but then it maybe goes too far toward being a language and makes things more complicated for the user?

On Aug 2, 2016, at 4:25 AM, Steven Borrelli [email protected] wrote:

Maybe this is part of the param definition, so that it can be used outside for API's & UI rendering.

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[sehqlr]

Could we have a valid/constraints field that takes a function? So, param "foo" { default = 5, constraint = NonZeroNum }, then have a function called NonZeroNum that checks the param during validate? That way, the config file is simpler, validation can be as detailed and simple as you like, and users can define their own constraints?

[sehqlr]

I'm going to remove this from the 0.3.0 project, in favor of tracking only the PR on that board