Thanks for considering contributing and help us on creating the Hydra protocols!
The best way to contribute right now is to try things out and provide feedback, but we also accept contributions to the documentation and the obviously to the code itself.
This document contains guidelines to help you get started and how to make sure your contribution gets accepted, making you our newest Hydra contributor!
See SUPPORT.md
should you have any questions or need some help in getting set up.
Contributing to the documentation, its translation, reporting bugs or proposing features are awesome ways to get started.
We host our documentation / user manual as a website here.
Each page has an "Edit this page" button which should take you to the source file containing the markup. Should you want to extend the documentation or find some errors, please file an issue pointing to the mistake or even better, create a pull request with the changes directly!
The documentation is also available in multiple languages and we can easily add more languages. If you want to extend, update or contribute a new translation make sure to check out the instructions in the docs component.
Submit an issue using the "Bug report 🐛" template. It's very important that you fill the template as thoroughly as possible.
Feature ideas are precursors to high-level features items, which will be discussed and fleshed out to ideally become items on our feature roadmap.
We use the Ideas discussions category to discuss and vote on feature ideas, but you can also submit an issue using the "Feature idea 💭" template and we convert that to a discussion.
We expect a description of
- why you (or the user) need/want something (e.g. problem, challenge, pain, benefit), and
- what this is roughly about (e.g. description of a new API endpoint or message format).
Note that we do NOT require a detailed technical description, but are much more interested in why a feature is needed. This also helps in understanding the relevance and ultimately the priority of such an item.
When contributing code, it helps to have discussed the rationale and (ideally) how something is implemented in a feature idea or bug ticket beforehand.
We use and require nix to provide a
consistent development environment via our flake.nix
.
Make sure that you have activated flakes in your nix.conf
:
substituters = https://cache.iog.io https://cache.nixos.org
trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
experimental-features = nix-command flakes
For Mac OS X users
Daemon mode is the recommended way to install and run nix on Mac OS. Therefore, you might want to add yourself as a trusted user in order to ensure flake's substituters will be picked up:
build-users-group = nixbld
trusted-users = root pascal
Then nix build
will ask you about using our caches and download or build the
hydra-node
into result/bin/hydra-node
. Other things you might want to build:
- Build the
hydra-node
using nix:nix build .#hydra-node
- Build a statically linked
hydra-node
using nix:nix build .#hydra-node-static
- Build the
hydra-node
docker image:nix build .#docker-hydra-node
- Build the specification as pdf:
nix build .#spec
For development, a call to nix develop
will put everything in place so that
you can:
- Build & run the
hydra-node
:cabal build hydra-node && cabal exec hydra-node -- --version
- Build & run all tests:
cabal test all
- Build & run all benchmarks:
cabal bench all
- Format code as enforced by CI:
treefmt
- Run
haskell-language-server
for an IDE experience - Run
hoogle
for symbol & documentation lookup
Also, some of us use direnv and nix-direnv to automatically import the nix environment into our favorite shell or editor and not need explicit call to enter the nix shell.
Besides these general build instructions, some components might document
additional steps and useful tools in their README.md
files, e.g. the
docs or the hydra-cluster
While warnings are not treated as errors during builds, CI will check for it before we merge any contributions.
Make sure to follow our Coding Standards. It includes guidelines on Haskell code style, but also on Git commit messages and some processes (TODO: clarify separation or unify with these guidelines). To propose new standards or changes to the existing standards, file an issue.
Thank you for contributing your changes by opening a pull requests!
On top of the aforementioned Coding standards, to get something merged would usually require:
- Description of the changes - if your commit messages are great, this is less important
- Quality of changes is ensured - through new or updated automated tests
- Change is related to an issue, feature (idea) or bug report - ideally discussed beforehand
- Well-scoped - we prefer multiple PRs, rather than a big one
- Correctness - a PR should pass all the build and test steps in the CI
Merging a PR requires approval from a majority of reviewers from the core Hydra engineering team. This implies that:
- Contributions from outside this core team would need 3 approvals,
- Contributions from a single core team member would need a single approval,
- PRs developed in pair would need a single approval,
- and of course PRs developed in ensembles would not need any approval.
The reason behind this policy is to increase the bus factor on the project, disseminating information about contributions and changes in order to prevent creation of a bottleneck.
Updating package dependencies from Hackage should work like normal in a Haskell
project. The most important thing to note is that we pin the index-state
of
the Hackage package index in cabal.project
. This means that cabal will always
see Hackage “as if” it was that time, ensuring reproducibility. But it also
means that if you need a package version that was released after that time,
you need to bump the index-state
(and to run cabal update
locally).
Because of how we use Nix to manage our Haskell build, whenever you do this you
will also need to pull in the Nix equivalent of the newer index-state
. You can
do this by doing a nix flake lock --update-input haskellNix/hackage
.
Many Cardano packages are not on Hackage and are instead in the Cardano Haskell
Packages (CHaP)
see the README for (lots) more information. Getting new packages from there
works much like getting them from Hackage. The differences are that it has an
independent index-state
, and that there is the CHaP
flake input which you
need to bump with nix flake lock --update-input CHaP
.
Sometimes we need to use an unreleased version of one of our dependencies,
either to fix an issue in a package that is not under our control, or to
experiment with a pre-release version of one of our own packages. You can use a
source-repository-package
stanza to pull in the unreleased version. Do this
only for a short period of time, and try to get your changes released
upstream. If that is (really) not possible, we can also release a patched
version into CHap, see their
README for
instructions.
During development
- Make sure
CHANGELOG.md
is kept up-to-date with high-level, technical, but user-focused list of changes according to keepachangelog - Bump
UNRELEASED
version inCHANGELOG.md
according to semver - Ensure
unstable
version of docker images is used in demosed -i.bak -e "s,\(ghcr.io/input-output-hk/hydra-[^:]*\):[^[:space:]]*,\1:unstable," demo/*
- All
hydra-
packages are versioned the same, at latest on release their versions are aligned. - Other packages are versioned independently of
hydra-
packages and keep a dedicated changelog.
To perform a release of next <version>
:
- Make sure all tests are passing.
- Publish hydra scripts onto
preview
,preprod
, andmainnet
using the smoke test and put the transaction ids as new<version>
entries into networks.json. - Update CHANGELOG.md by replacing
UNRELEASED
with a date in ISO8601 and prepare contents. - Run
./release.sh <version>
- Check if all the bumped versions are correct. In particular, whether the demo
and tutorial would still work given the changelog. If everything is fine,
push the branches
master
,release
and the<version>
tag. - Create a github release page containing
- The released changes (formatted) and giving credit where credit is due
- Built hydra (and cardano-node) binaries to the release using naming scheme:
hydra-<platform>-<version>.zip
whereplatform
isx86_64-linux
oraarch64-darwin
(the same forcardano-node
instead ofhydra
) - The just published
hydra-scripts-tx-id
from step 1
We have several reporting and communication practices within the Hydra project. Becoming one of the core contributors of the project includes participation in core communication processes.
At the end of every two weeks, we provide updates to cardano-updates, which also serve as a basis for our monthly reports.
To write such an update:
-
Use the contributors tactical meeting agenda to collect bullet points on
-
What did the team achieve this sprint: past tense summary of done things (good: "Implemented..", bad: "Started working on.."); use the backlog and calendars to collect
-
What are the goals of next sprint: a short look-out onto the backlog and/or roadmap; ask each contributor what they would like to get done next week; always start from scratch and don't carry over things from last week.
-
-
Enrich the content with useful links and write a high-level summary. This should use a passive or "they"-style of writing. Tip: check out older updates for examples and/or use an AI language model to write it.
-
Create a entry blog and pull request it on cardano-updates, putting other Hydra contributors as reviewers.
- Don't forget to add yourself as author in the
authors.yml
.
- Don't forget to add yourself as author in the
To keep our users and stakeholders up-to-date regularly, we organize a review meeting and publish a report every month to the project website.
To conduct this meeting and write this report:
-
Monthly meeting slides & report preparation:
-
Ensure the Google Meet invitation exists for this month and check stakeholder attendance
-
Copy monthly slides, change title and template accordingly to
<Month> <Year>
-
Remove old "content" slides and mark the regular slides to be updated
-
Decide what to demonstrate (this is not optional!), either from the core development or an invited demo/showcase from the community
-
Update delivered / current / next features
-
Expand some of those into interesting "Development" topics
-
Summarize what happened in the Hydra "Community"
- Reach out to individuals from the community whether they want to contribute something to the monthly
-
Update roadmap for this month
-
Update repository status in slides using https://github.com/input-output-hk/hydra/pulse/monthly
-
Prepare invitation, by creating an event in discord, update the invitation used last month with it.
-
Send invitation to Hydra and Mithril #announcements channels on our discord server.
-
-
Conduct the meeting
- Do not forget to record the meeting!
- Ask for sharing rights after the meeting, by requesting sharing in Google Drive with yourself, and/or ask for making it publicly available.
-
Write the report in this repository
- Copy monthly report from last month, update dates, links to slides and closed issues
- Use slides as starting point, to provide a short and sweet written account of what happened
- The previous reports should serve as a guideline
- Distribute write-up between relevant contributors
- Cross-link slides, recording and report
- Pull request, review and merge to publish the report
NOTE: Drafting the report (step 3) is also a good preparation for presenting the individual sections.