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RE: "I like many things about Ansible, but the 'language' is an unreadable mess that makes termcap[1] feel like genius level UX design." I've been a puppet use

by willejs 10y ago

RE: "I like many things about Ansible, but the 'language' is an unreadable mess that makes termcap[1] feel like genius level UX design." I've been a puppet user, and long time chef user, and recently been using ansible for a couple of projects, but I can't learn to like the 'language' at all. I feel like ansibles YAML syntax is just hiding the complexity of configuration management from you. Which at first as a novice ansible and CM user, or for small projects is great! You can be super productive, and anyone can understand it in your team. However, as your systems get more complex, I feel like doing anything remotely complex with it produces confusing, hacky, unreadable ansible 'code'. Then you try to scale this working in a team, and try to do any useful testing, or re-use/extend/share any roles, your kind of doomed. The reason I continue to use chef is because its a ruby DSL that you can easily extend, where anyone who can code; can write, test and understand. While I find Ansible is just templated YAML, and means you dont have to understand how to program. I guess my point is, configuration management is kind of hard. I feel like people use Ansible because 'its easy', and I hear people say 'Ansible is easy' a lot. But in the end, Ansible, the tool chain, workflows and syntax will become just as complex as chef/puppet/saltstack when you operate it at scale.

gerbilly 10y ago
I think we have to distinguish two things going on in Ansible files. 1) It's declarative. So if you are looking for a procedural language, you will be disappointed. It's also declarative for good reason IMHO. 2) It's still hacky. If the 'language' remained entirely declarative then the YAML syntax _might_ have been ok, but the language looks like a poor design stretched beyond it's limits. Some people don't like the Ansible language for reason 1 or some for reason 2. Personally, I prefer that it's declarative, the file is supposed to describe the features the target system must have, and then the module, which is procedural, has to figure out how to make that happen on whatever target system is in question. That separation keeps things clean, idempotent (most times) and neat. I think procedural approaches _seem_ better because they are familiar to programmers, but they can become complex, non-idempotent and hard to debug.
- phunge 10y ago
  Agreed, this is a great way to think about it. I think Ansible is at its best when the modules handle the imperative stuff behind the scenes, and the playbook just declares. That's not always possible, but the modules are getting better and better. FWIW I also found YAML to be very confusing syntactically at first; things got easier once I realized that it's basically 1-to-1 with JSON, and could convert to JSON to get intuition for the file structure (simple yaml2json script here: http://pastebin.com/TpjZLnLa http://pastebin.com/TpjZLnLa). Thumbing through the book Ansible Up and Running also helped. In the long run, putting a declarative idempotent layer atop the same old mutable infra is tough but a necessary compromise right now. It'll be great if the immutable-first tools of today (nixos et al) mature and we can leave this behind.
- Florin_Andrei 10y ago
  Every time I let the config management stuff slide slowly towards procedural, bad things have happened. You want your config management templates to be as declarative as possible. "This is the desired final state", and that's it. Of course, in practice it's very hard to stay 100% declarative, but it's very good practice to try and keep it close to ideal.
- Poiesis 10y ago
  I've used Ansible quite a bit, and I could sometimes sum it up as, "the worst one, except for its alternatives". I tend to think of Ansible as supporting a flexible combination of declarative and procedural approaches. Within a particular sequence of tasks, it's procedural. Those lists of tasks are typically combined into a role or the like that is typically more declarative in its application. Of course application of roles is actually procedural in that it happens in the same obvious order it's defined, but the higher level organizational constructs like roles have more of a declarative feel to me (I'd assume that's by design).
- GauntletWizard 10y ago
  Ansible has none of the things that make declarative languages good, though. Good Declarative languages allow composition - Having a base object, adding properties to it, overriding others. Ansible handles none of that in it's playbook syntax or it's vars syntax. In the role and module syntax, sure, but they're turing complete anyway.

by willejs 10y ago

gerbilly 10y ago

I think we have to distinguish two things going on in Ansible files. 1) It's declarative. So if you are looking for a procedural language, you will be disappointed. It's also declarative for good reason IMHO. 2) It's still hacky. If the 'language' remained entirely declarative then the YAML syntax _might_ have been ok, but the language looks like a poor design stretched beyond it's limits. Some people don't like the Ansible language for reason 1 or some for reason 2. Personally, I prefer that it's declarative, the file is supposed to describe the features the target system must have, and then the module, which is procedural, has to figure out how to make that happen on whatever target system is in question. That separation keeps things clean, idempotent (most times) and neat. I think procedural approaches _seem_ better because they are familiar to programmers, but they can become complex, non-idempotent and hard to debug.

phunge 10y ago
Agreed, this is a great way to think about it. I think Ansible is at its best when the modules handle the imperative stuff behind the scenes, and the playbook just declares. That's not always possible, but the modules are getting better and better. FWIW I also found YAML to be very confusing syntactically at first; things got easier once I realized that it's basically 1-to-1 with JSON, and could convert to JSON to get intuition for the file structure (simple yaml2json script here: http://pastebin.com/TpjZLnLa http://pastebin.com/TpjZLnLa). Thumbing through the book Ansible Up and Running also helped. In the long run, putting a declarative idempotent layer atop the same old mutable infra is tough but a necessary compromise right now. It'll be great if the immutable-first tools of today (nixos et al) mature and we can leave this behind.
Florin_Andrei 10y ago
Every time I let the config management stuff slide slowly towards procedural, bad things have happened. You want your config management templates to be as declarative as possible. "This is the desired final state", and that's it. Of course, in practice it's very hard to stay 100% declarative, but it's very good practice to try and keep it close to ideal.
Poiesis 10y ago
I've used Ansible quite a bit, and I could sometimes sum it up as, "the worst one, except for its alternatives". I tend to think of Ansible as supporting a flexible combination of declarative and procedural approaches. Within a particular sequence of tasks, it's procedural. Those lists of tasks are typically combined into a role or the like that is typically more declarative in its application. Of course application of roles is actually procedural in that it happens in the same obvious order it's defined, but the higher level organizational constructs like roles have more of a declarative feel to me (I'd assume that's by design).
GauntletWizard 10y ago
Ansible has none of the things that make declarative languages good, though. Good Declarative languages allow composition - Having a base object, adding properties to it, overriding others. Ansible handles none of that in it's playbook syntax or it's vars syntax. In the role and module syntax, sure, but they're turing complete anyway.