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Try Argo using Nix

Nix is a package manager / build tool which focuses on reproducible build environments. Argo Workflows has some basic support for Nix which is enough to get Argo Workflows up and running with minimal effort. Here are the steps to follow:

  1. Modify your hosts file and set up a Kubernetes cluster according to Running Locally. Don't worry about the other instructions.
  2. Install Nix.
  3. Run nix develop --extra-experimental-features nix-command --extra-experimental-features flakes ./dev/nix/ --impure (you can add the extra features as a default in your nix.conf file).
  4. Run devenv up.

Warning

This is still bare-bones at the moment, any feature in the Makefile not mentioned here is excluded for now. In practice, this means that only a make start UI=true equivalent is supported at the moment. As an additional caveat, there are no LDFlags set in the build; as a result the UI will show 0.0.0-unknown for the version.

How do I upgrade a dependency?

Most dependencies are in the Nix packages repository but if you want a specific version, you might have to build it yourself. This is fairly trivial in Nix, the idea is to just change the version string to whatever package you are concerned about.

Changing a python dependency version

If we look at the mkdocs dependency, we see a call to buildPythonPackage, to change the version we need to just modify the version string. Doing this will display a failure because the hash from the fetchPypi command will now differ, it will also display the correct hash, copy this hash and replace the existing hash value.

Changing a go dependency version

The almost exact same principles apply here, the only difference being you must change the vendorHash and the sha256 fields. The vendorHash is a hash of the vendored dependencies while the sha256 is for the sources fetched from the fetchFromGithub call.

Why am I getting a vendorSha256 mismatch ?

Unfortunately, dependabot is not capable of upgrading flakes automatically, when the go modules are automatically upgraded the hash of the vendor dependencies changes but this change isn't automatically reflected in the nix file. The vendorSha256 field that needs to be upgraded can be found by searching for ${package.name} = pkgs.buildGoModule in the nix file.

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