I see (and I saw your post on create_resources - I tested it out and also
noticed that inheritance didn't work as expected for me either). My
initial thought would be to try and break down the individual sysctl
entries as individual resources that could be declared with a defined type
(as Aaron mentioned) - then you can use hiera to declare them with
create_resources() AS WELL as individually declaring additional resources.
On Fri, May 11, 2012 at 9:47 AM, Luke Bigum <luke.bi...@lmax.com> wrote:
> Hi Gary,
>
> Not quite... Let me go into more detail.
>
> I'm trying to handle sysctl "perfectly" which is probably my real problem.
> Hiera's ability to merge hashes together makes it perfect for arriving at
> one set of sysctl options for a server based on "business logic" (my
> hierarchy). For Hiera data on 'someserver' below which has 'some_role',
> calling hiera_hash in a Puppet manifest will give me IP forwarding set and
> rp_filter set, which is what I want:
>
> --------- some_role.json ------------
> {
> "sysctl" : {
> "net.ipv4.ip_forward" : {
> "comment" : "Controls IP packet forwarding",
> "value" : "1"
> }
> }
> --------------------------------------------
> --------- common.json ----------
> {
> "sysctl" : {
> "net.ipv4.ip_forward" : {
> "comment" : "Controls IP packet forwarding",
> "value" : "0"
> },
> "net.ipv4.conf.default.rp_filter" : {
> "comment" : "Controls source route verification",
> "value" : "1"
> }
> ...
> ...
> }
> -------------------------------------
>
> Where it becomes difficult is trying to then incorporate pure Fact data to
> influence or modify these decisions.
>
> Lets say that I actually get back 20 keys of sysctl data, one of those is
> 'vm.swappiness'. Most of my nodes have a value of '10', but lets say
> hypothetically that I have a small set of nodes that require a different
> value because of the amount of RAM available in the machine (a decision
> needs to be made based on hardware, not business logic). This is purely a
> Fact. Introducing another level of hierarchy for Fact 'memorytotal' is a
> bit silly in this case.
>
> The sysctl class looks roughly like this:
>
> ------- sysctl.pp ----------
> class sysctl {
> $sysctl_hash = hiera_hash('sysctl')
> create_resources('sysctl', $sysctl_hash)
> }
> ------------------------------
>
> I love that simplicity, however it's difficult to introduce edge cases
> that modify the data retrieved from Hiera based on Facts. Class inheritance
> won't work because create_resources() seems to insert into the catalog in
> an uninheritable way - bug report or fixable with Ruby DSL perhaps? Filling
> this class full of "if ($fact) modify hash" to munge the data pulled from
> Hiera seems dirty too.
>
> There may be no elegant solution and as you say, 80-90% may have to do.
>
> -Luke
>
>
> On 11/05/12 16:53, Gary Larizza wrote:
>
> I see this with people looking to move to the hierarchical system that
> Hiera brings. It essentially boils down to "How do I do this without
> having a ton of hierarchy levels?". Usually we tend to recommend using the
> hierarchy to hit the 80% mark for the data you need in your modules.
> Anything that's module-specific-data should then be broken out to a
> data.pp or params.pp file with conditional logic there. I tend to ask
> people: "Is this something others are going to hit when they try to use the
> module too?", as in - "Are there path differences between operating
> systems?", or "Are there important changes to the data between RHEL 5 and
> 6?". If the answer to these is yes, then I tend to favor putting that data
> into a module's data class so that it's exposed for ANYONE who wants to use
> the module. Why would you want to hide these differences in the hierarchy
> - especially if others might run into them?
>
> Does this sound similar to the problems you're facing? Or is this a
> case where you have custom facts that are specific to your organization
> that determine how you manage sysctl?
>
>
> On Fri, May 11, 2012 at 8:42 AM, Luke Bigum <luke.bi...@lmax.com> wrote:
>
>> Hi all,
>>
>> I've been improving our sysctl module and come across an interesting
>> design problem I'd like feedback on.
>>
>> I approached the re-factor with Hiera in mind - I would put all our
>> sysctl data in Hiera hash and pull that into a hiera_hash, merging the
>> hierarchy of data and allowing higher priority sysctl settings to override
>> the baseline defaults. I then use create_resources to write sysctl.conf.
>> Works great to start with, but now I come across more and more cases where
>> the sysctl data is dependent on machine logic (virtual vs physical, types
>> of hardware, etc) that doesn't seem right to put into Hiera as I'd have a
>> complex hierarchy for a bunch of edge case Facts.
>>
>> I seem to need to make decisions on two sources: business logic in Hiera
>> hierarchy (that's easy with merging hashes) as well as considering what
>> Facts or Classes applies to a node (machine logic). That's not trivial to
>> do, especially with a potentially large set of data like sysctl.conf keys.
>>
>> Does anyone have any thoughts or tips on how they might be managing a
>> similar situation?
>>
>> Thanks,
>>
>> -Luke
>>
>> --
>> Luke Bigum
>>
>> Information Systems
>> Ph: +44 (0) 20 3192 2520
>> luke.bi...@lmax.com | http://www.lmax.com
>> LMAX, Yellow Building, 1A Nicholas Road, London W11 4AN
>>
>>
>> FX and CFDs are leveraged products that can result in losses exceeding
>> your deposit. They are not suitable for everyone so please ensure you
>> fully understand the risks involved. The information in this email is not
>> directed at residents of the United States of America or any other
>> jurisdiction where trading in CFDs and/or FX is restricted or prohibited
>> by local laws or regulations.
>>
>> The information in this email and any attachment is confidential and is
>> intended only for the named recipient(s). The email may not be disclosed
>> or used by any person other than the addressee, nor may it be copied in
>> any way. If you are not the intended recipient please notify the sender
>> immediately and delete any copies of this message. Any unauthorised
>> copying, disclosure or distribution of the material in this e-mail is
>> strictly forbidden.
>>
>> LMAX operates a multilateral trading facility. Authorised and regulated
>> by the Financial Services Authority (firm registration number 509778) and
>> is registered in England and Wales (number 06505809). Our registered
>> address is Yellow Building, 1A Nicholas Road, London, W11
>> 4AN.
>>
>> --
>> 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.
>>
>>
>
>
> --
>
> Gary Larizza
> Professional Services Engineer
> Puppet Labs
>
> --
> 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.
>
>
>
> --
> Luke Bigum
>
> Information Systems
> Ph: +44 (0) 20 3192 2520luke.bi...@lmax.com | http://www.lmax.com
> LMAX, Yellow Building, 1A Nicholas Road, London W11 4AN
>
>
> FX and CFDs are leveraged products that can result in losses exceeding
> your deposit. They are not suitable for everyone so please ensure you
> fully understand the risks involved. The information in this email is not
> directed at residents of the United States of America or any other
> jurisdiction where trading in CFDs and/or FX is restricted or prohibited
> by local laws or regulations.
>
> The information in this email and any attachment is confidential and is
> intended only for the named recipient(s). The email may not be disclosed
> or used by any person other than the addressee, nor may it be copied in
> any way. If you are not the intended recipient please notify the sender
> immediately and delete any copies of this message. Any unauthorised
> copying, disclosure or distribution of the material in this e-mail is
> strictly forbidden.
>
> LMAX operates a multilateral trading facility. Authorised and regulated
> by the Financial Services Authority (firm registration number 509778) and
> is registered in England and Wales (number 06505809).
> Our registered address is Yellow Building, 1A Nicholas Road, London, W11
> 4AN.
>
> --
> 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.
>
--
Gary Larizza
Professional Services Engineer
Puppet Labs
--
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.
