OCaml Weekly News

Hi folks! :wave: happy to announce castore 0.0.1.

tl;dr I’m taking a page from the Elixir community’s playbook here, the Ca_store module includes an up-to-date public certificate chain from a generally trustworthy source (eg. Mozilla) that we’ll update via CI and publish automatically to opam periodically.

How to use it Easy, just opam install castore and in your dune-project make sure to use (castore (>= "0.0.0")) so you automatically upgrade to the latest certificate.

Now you can use it with ocaml-tls and when you need that .pem file you can feed it the contents of Ca_store.pem.

Why we did this I was building an HTTP client for Riot and realized that to support TLS I’d need to either have custom certificates or bring in ca-store and let it resolve them from the system.

The Elixir community’s approach to this is a lot simpler.

What’s missing/next The latest .pem file was updated on Dec 12th and I need to build the scheduled CI workflow that’ll update it / publish the lib, so if you’re into crypto (maybe i can nerdsnipe @hannes?) or ci (@ulrikstrid?) then ping me :)

Happy hacking! :camel:

/ Leandro

I spent a little time consolidating that preprocessing code into castore, and 0.0.2 is on its way on opam.

It’ll let you write this:

let decode_pem ca =
  let ca = Cstruct.of_string ca in
  let cert = X509.Certificate.decode_pem ca in
  Result.get_ok cert
in
let cas = List.map decode_pem Ca_store.certificates in
let authenticator = X509.Authenticator.chain_of_trust ~time cas in
let tls_config = Tls.Config.client ~authenticator () in
(* ... *)

Heya everyone!

This weekend I had some fun and built a fixture generator in OCaml! It is my very first DSL.

I found it very time consuming to set up test data, especially when dealing with relational data, where some data generated needs to reference some other data. Therefore, I wanted a slim DSL that can be used to quickly generate test data which I can import it into SQL or NoSQL.

So to give an example:

~: fixgen 'user (2): id uuidv4, name name; order (5): id uuidv4, buyer user.id, amount int(1,40), currency
("USD","MXN")'

FILE NAME: user
name,id
Ivan,1aa2f650-95b2-477a-9ccf-88c46d927e4e
Judy,0bb7258f-8843-4997-97a8-08351623a9d1

FILE NAME: order
currency,amount,buyer,id
USD,14,1aa2f650-95b2-477a-9ccf-88c46d927e4e,42362e8d-2c22-443a-8851-62e9b2cd18cf
MXN,19,0bb7258f-8843-4997-97a8-08351623a9d1,ebccf8db-de5b-4744-bd99-7e299fb3107a
MXN,17,1aa2f650-95b2-477a-9ccf-88c46d927e4e,b23ee86d-d69e-4270-9156-944277a46ea1
MXN,32,1aa2f650-95b2-477a-purchase9ccf-88c46d927e4e,cc9d05c2-4921-415d-820e-4713aefd5593
USD,29,1aa2f650-95b2-477a-9ccf-88c46d927e4e,921738da-b0e3-4d50-ac7e-d243805ecfe8

It can also export to JSON!

~: fixgen 'user (2): id uuidv4, name name; purchase (5): id uuidv4, buyer user.id, amount int(1,40), currency
("USD","MXN")' -f json

FILE NAME: user
[{"name": "Ivan", "id": "f6c90f96-faad-4741-a52b-6d53b94d48f3"}, {"name": "Judy", "id":
"57eccc5c-ad09-4229-b0c7-a828280dba1b"}]

FILE NAME: purchase
[{"currency": "USD", "amount": 14, "buyer": "f6c90f96-faad-4741-a52b-6d53b94d48f3", "id":
"8e59075c-1a6a-4093-86ca-e1135afd34f3"}, {"currency": "MXN", "amount": 19, "buyer":
"57eccc5c-ad09-4229-b0c7-a828280dba1b", "id": "fd89ad30-af07-4c9d-9ec4-ade7583e9cf0"}, {"currency": "MXN",
"amount": 17, "buyer": "f6c90f96-faad-4741-a52b-6d53b94d48f3", "id": "b15cd3d7-ede1-4612-b0f2-a36cc1a73f1c"},
{"currency": "MXN", "amount": 32, "buyer": "f6c90f96-faad-4741-a52b-6d53b94d48f3", "id":
"295a85b8-42d9-49a4-8ce6-e4d7b1a94ea9"}, {"currency": "USD", "amount": 29, "buyer":
"f6c90f96-faad-4741-a52b-6d53b94d48f3", "id": "925eff95-b7a2-4cbe-93b9-b519372a16cf"}]

For now it doesn’t have many generators (I plan to add more), the docs are a bit sparse and I don’t know if I shared the compiled binary correctly. However, I wanted to share it early to gather feedback!

Hi everyone :wave:

I’ve been using Haskell in production for the previous 8 years. But for the last 8 months, I used OCaml at Bloomberg.

I wrote a blog post comparing two languages from my POV:

• Dev.to: 8 months of OCaml after 8 years of Haskell in production (by @chshersh)

I tried to provide a reasonable and balanced overview of these two languages, although my experience in both is significantly different. I hope this blog post can give a rough idea of both languages :relieved:

Enjoy! And let me know any feedback you have!

Hi folks :wave: we skipped over 0.0.6 because of a CI bug, and ended up releasing Riot 0.0.7 instead :slight_smile:

Here’s a summary of the changes.

Hi folks :wave: I have been willing to share Spatial Shell here for a while now, mostly because it is implemented in OCaml so it’s a good way for me to find potential contributors ahah (unfortunately, the codebase could be more commented tbh). Spatial Shell implements a spatial model inspired by Material Shell for i3 and sway. I have very recently tagged its 6th release, and I believe now is a good time to try and put it in the hands of other human beings. What might go wrong? :sweat_smile:

The README should be comprehensive enough to get you started, and I’ve also published a short blogpost giving a bit more background on my Spatial Shell journey, and has a nice video you can witch if you are curious.

If you run into problems while trying to test, do not hesitate to reach out (GitHub issues are probably the best way to do so). I do hope Spatial Shell becomes a usable programs for anyone interested in the workflow it enables on i3/sway deskop.

Here are links from many OCaml blogs aggregated at the ocaml.org blog.

• Announcing the ORCHIDE Project: Powering Satellite Innovation