kubernetes-mock-rs

Mock Kubernetes client for testing things that interact with the Kubernetes API, including controllers.

View documentation, examples, and more by running make doc. (link to docs.rs to come when published!)

488 lines of code, but that's 24% doc comments.

Features

• Very simple to mock, just make the same API calls as your program should make
• Easy setup errors with good documentation - if there are problems, it should help you solve them
• Verbose errors when tests fail, showing you exactly what went wrong
• Works with multiple versions of Kubernetes (currently v1.25, v1.21) - to change versions, please use features v1_25 or v1_21.
  • Default is v1.25, if you want to use a different version please remember to use default-features = false in your Cargo.toml

Example

Minimal compilable example:

use kubernetes_mock::*;
use kube::{Api, api::ListParams};
use k8s_openapi::api::core::v1::Node;
#[tokio::main]
async fn main() {
    let (client, mut mocker) = make_mocker();
    let api: Api<Node> = Api::all(client);
    mocker.expect(|| async {
        let nodes = api.list(&ListParams::default()).await;
      },
      MockReturn::List(&[Node::default()]),
    ).await.unwrap();
    // ...
    let handle = tokio::spawn(mocker.run());
    api.list(&ListParams::default()).await;
    handle.await.unwrap().unwrap(); // Assert tests pass with `unwrap()`.
    // Requires two calls to unwrap - one for tokio spawn result, the other for the mocker result
}

Note: unwrap() is not great for formatting, if you'd like to see errors pretty printed you can do the following:

if let Err(e) = handle.await.unwrap() { // still need one unwrap() for tokio spawn
    panic!("{e:#?}"); // debug pretty-print
}

Still Todo

• Testing mocker.watch() - it works but is not tested.
  • We could use a controller to test this, to show how it works.
• More edge cases tested - functions passed to expect() panicking, etc.
• Explore better API design?
  • Can we let expect() take multiple API calls, meaning people can use one for all API calls
• Should/could we be less restrictive (e.g. unordered API calls, allowing the same call multiple times/"more than once", allowing different parameters)?

Feel free to help, check out CONTRIBUTING.md!

Distributed under Apache 2.0. See LICENSE for more information.