Hacker News Reader

Comment by Fizzadar | Hacker News Reader

I think I tried to shy away from specifically being "Ansible does this bad so pyinfra does this" and instead focus on the features that differentiate like "Instant debugging with realtime stdin/stdout/stderr output (-vvv).". But it seems like that isn't enough and the landing page needs to be more explicit in comparison. Ty for the feedback!

View on HN

I applaud trying to be positive and focus on "this is what we do well," but yeah at least some explicit comparison would help. The copy right now is kind of assuming the reader already knows Ansible to compare against as a baseline. Which is probably fair for most people who find your project, but people who find your project are also probably not happy with Ansible and want to know if this addresses their pain points immediately.

Is very interesting though, I think I'm gonna try it myself.

I like Ansible, but that doesn't mean thera are no pain points.

One of them is handling "if-this-then-that-else-that". Being purely declarative, Ansible is horrible at that.

Pyinfra can be used in imperative mode, am I right? This would make the use of if-else a breeze, which would be a really good reason for me to to switch.

Ansible is declarative?

In puppet and saltstack you can declare that a folder is empty and declare a specific file in this folder. The system's smart enough to delete all the files except the one.

To achieve such feat in ansible is hard. Easiest way is to have two tasks, one deletes everything and second recreates your file. Doesn't feel very declarative

Unrelated thing, they don't even try to be declarative in ansible E.g you can have a file with state "touch". It not a state if it updates each playbook run!

You're confusing declarative with idempotent. Ansible is both, it won't change anything if the state is already what you declared. The nitpicked case you chose, you want the file to have the latest timestamp, this is a valid state to declare.

Ansible is neither and it shows. For example, deleting a configuration in Ansible doesn't revert the system back to its original state. That's the definition of statefulness.

The shell task breaks the declarative nature a bit, along with registering task results and then writing conditional whens based on them. Interpolating values based on the registered results does too imho

Plus, what your are declaring is often times not the state you desire but... action you want to take. Say you use `apt.name: [pkg1, pkg2]`, run it, then remove `pkg2` from the list. Running this again won't remove `pkg2` from your system. So it's declarative, but not necessarily on the optimal level all the times.

Ansible tries to be declarative and idempotent, but fails at being both.

ansible-core succeeds pretty well in being both.

ansible modules (built-in and community) are a different matter. generally, quality will vary.

Ansible is neither.

There's a lot of cases where Puppet fails on something similar. Packages is probably the easiest example. Puppet won't remove all package not explicitly declared, nor will it remove files it created, if you remove the Puppet code for managing that file.

I'm fairly sure that the way to make Puppet do what you suggest is the same in Puppet and Ansible. The difference is that Puppet is smart enough to not actually remove you file during every run (I think). On the other hand, Ansible will normally not be configured to run every 30 minutes like Puppet, so it's much less of an issue.

Both tools are great but they work some what differently. How you think about using them is much the same though, you need to tell the computer what to do. In Puppet this is often talked about is if you describe the state, I suppose that's partly true, but in the end you have a series of actions the computer will need to take to achieve this state.

You can use Rsync to to a puppet created folder You’d need to have a source folder with the file which is fine

rsync covers this and should ne used instead of a lot of Ansible tasks

There's definitely a trend in this direction.

Pulumi for Terraform and Dagger for Docker are two examples I use

I like CUE as a language to replace my Yaml that has some of the typical language constructs but maintains the declarative approach

Is performance better than Ansible? I have used Ansible extensively and find it excruciatingly slow.

Yes! https://docs.pyinfra.com/en/next/performance.html

Hi @Fizzadar and congrats on making this and getting it out the door; kudos!

As you craft your "Why this and not Ansible" content, you might actually state clearly what you already noted on the Performance page, namely: "One of the reasons pyinfra was started was performance of agent-less tools at the time." If I read that, it'd instantly make me want to stick around and read some more, play with pyinfra, etc. BTW, i will be playing with it anyway, but just wanted to point out that you likely won;t need to start from scratch for copy (on a comparison or answering "Why this and not Ansible" content). Cheers!

Excruciatingly slow is an understatement :)

Why being slow is a bad thing? Ansible gives me a legitimate excuse to have proper lunch. ;-)

You're supposed to be writing compilers during that time

That would be appreciated. I saw the homepage and my first thought was "Ansible is python. How are these things different?" Obviously pure python vs yaml is one thing. But beyond that it's not clear. Perhaps are specific use cases in your mind where one or the other is a better fit, and that would be helpful as well.

Reply on news.ycombinator.com