Only show deprecation messages when new versions exist

[komalali]

Proposed changes

We now check if the suggested kind exists in the current k8s cluster version before showing a deprecation message.

It's kind of a pain to figure out which kinds were added in which spec version, so I wrote a little node script to generate a list for me. Not sure if it's useful to put it somewhere, but I've pasted it here and open to ideas.

const fetch = require("node-fetch");

// Fetches the spec for the specified version and returns an array of keys for all the 
// definitions with the 'x-kubernetes-group-version-kind' property (signifying a GVK).
async function getSpec(version) {
    const response = await fetch(`https://raw.githubusercontent.com/kubernetes/kubernetes/release-1.${version}/api/openapi-spec/swagger.json`);
    const json = await response.json();
    const types = [];
    Object.entries(json.definitions).forEach(([key, val]) => {
        if (val['x-kubernetes-group-version-kind']) {
            types.push(key)
        }
    })
    return types;
}

// Map through the versions and collect all the resources that are not present in the 
// previous version.
(async function main() {
    const versions = [13, 14, 15, 16, 17, 18];
    const versionMap = {};
    const results = await Promise.all(versions.map(getSpec));
    results.forEach((result, index) => versionMap[`v${versions[index]}`] = result);

    const newResources = {};

    function getNewResources(version) {
        const newInVersion = [];
        versionMap[`v${version}`].forEach(resource => {
            if (!versionMap[`v${version - 1}`].includes(resource)) {
                newInVersion.push(resource);
            }
        })
        newResources[`v${version}`] = newInVersion;
    }

    for (let i=1; i<versions.length; i++) {
        getNewResources(versions[i])
    }

    console.log(newResources);
})()

Related issues (optional)

Fixes: #1168

[lblackstone]

LGTM overall!

[lblackstone]

It's kind of a pain to figure out which kinds were added in which spec version, so I wrote a little node script to generate a list for me. Not sure if it's useful to put it somewhere, but I've pasted it here and open to ideas.

We may eventually want to turn this into something that runs as part of code generation (translated to Go). Can you open an issue to track that?

[lblackstone]

One more fix, and then LGTM