mazzle VS dhall-lang

I've been experimenting with alternative pipeline syntaxes.

One example is using Graphviz graph files as an execution plan for software deployments. You can see a graph here:

https://github.com/samsquire/mazzle/blob/master/docs/archite...

I wrote code with networkx to parse this graph dot file and then follow the plan topologically, spinning up packer, terraform, bash scripts, compilation and so on. It also executes graph nodes in parallel where it can.

I talk about it here https://devops-pipeline.com/

My problem with bash pipelines is passing data along and referring to previous steps' data. You kind of need to enrich the data that goes along the pipeline.

I use Graphviz dot syntax to configure entire cloud computing environments in the order they must be built. This is pipelines as code and infrastructure as code

It's very powerful! Not every organisation can bring up an entire environment with one command.

Here is a executable diagram of a build worker cloud nodes, Kubernetes, consul, vault, Debian package server, Java app, SSH bastion, Prometheus, grafana, DNS and security groups.

https://github.com/samsquire/mazzle/blob/master/docs/archite...

The tool also parallelises the build based on the graph so packer builds can run in parallel.

https://devops-pipeline.com/

It also has a GUI but it's not ready for other people to use.

I use a tool I wrote to layer my infrastructure with layers called components and I configure it with a Graphviz file.

My tool, called mazzle (previously devops-pipeline) would run parts of the graph that can run in parallel in parallel. It can also run parts of the build on SSH workers. You bring up the workers at the beginning of the build.

Here's an example of a graph generated from graphviz file: https://github.com/samsquire/mazzle/blob/master/docs/archite...

This graph brings up a hashicorp vault server, Java application, bastion proxy etc.

here's the graphviz file: https://github.com/samsquire/mazzle-starter/blob/master/arch...

It describes the ordering of the infrastructure, the invocation of Ansible, packer, shell scripts to set up vault etc.

The idea is to be able to bring up a new environment by changing one parameter. There's a React GUI too.

https://devops-pipeline.com

Fail to see how this is any different than Dhall (https://dhall-lang.org/) other than it produces plists too.

Kubernetes config is a decent example. I had ChatGPT generate a representative silly example -- the content doesn't matter so much as the structure:

https://gist.github.com/cstrahan/528b00cd5c3a22e3d8f057bb1a7...

Now consider 100s (if not 1000s) of such files.

I haven't given Pkl an in depth look yet, but I can say that the Industry Standard™ of "simple YAML" + string substitution (with delicate, error prone indentation -- since YAML is indentation sensitive) is easily beat by any of:

- https://jsonnet.org/

- https://nickel-lang.org/

- https://nixos.org/manual/nix/stable/language/index.html

- https://dhall-lang.org/

- (insert many more here, probably including Pkl)

There are underpowered languages / tools, that can only solve a problem for which they are intended poorly. But not all limited tools are like that.

Say, eBPF is prominently not Turing-complete, which allows to guarantee that a eBPF program terminates, and even how soon. Still eBPF is hugely useful in its area.

Or, say, regular expressions are limited to regular languages; in particular, they famously [1] cannot process recursive structures, like trees. Still tools like grep / ag / rg are mightily useful.

Yes, I agree that YAML is underpowered for proper k8s configuration! But it's also too powerful for its own good in other aspects [2]. I wish Google used Dhall [3] or their own purely functional config language (FCL? I already forgot the name) instead of YAML; sadly, they did not.

[1]: https://stackoverflow.com/a/1732454/223424

[2]: https://ruudvanasseldonk.com/2023/01/11/the-yaml-document-fr...

[3]: https://dhall-lang.org/

Dhall: Dhall is a programmable configuration language that combines features like JSON, functions, types, and import capabilities. Its style leans towards functional programming, so if you're familiar with functional-style languages such as Haskell, you might find Dhall to be quite intuitive.

I've been thinking along these lines but more 'strongly validated' than statically typed in the sense that you'd be better off being able to load the entire config and then produce a list of problems (and should be able to offer good editor support if done correctly).

Though https://dhall-lang.org/ demonstrates that you can statically type quite a lot of configuration to great advantage, which appears to be programmatically embeddable in multiple languages per https://docs.dhall-lang.org/howtos/How-to-integrate-Dhall.ht...

> Where practical is in the sense of an engineer (or in their terms, a CS practitioner),

Configuration processing. E.g. I'd like my yamls to be decidable, though I'd settle for guaranteed to halt[1].

[1] https://dhall-lang.org/

Maybe you'd like jsonnet: https://jsonnet.org/

I find it particularly useful for configurations that often have repeated boilerplate, like ansible playbooks or deploying a bunch of "similar-but" services to kubernetes (with https://tanka.dev).

Dhall is also quite interesting, with some tradeoffs: https://dhall-lang.org/

A few years ago I did a small comparison by re-implementing one of my simpler ansible playbooks: https://github.com/retzkek/ansible-dhall-jsonnet

And to checkout Dhall: https://dhall-lang.org/