watch.js

//
// Watch changes to a Deployments in a specific Namespace.
//
const Client = require('../lib').Client;
const config = require('../lib').config;
const JSONStream = require('json-stream');

const deploymentManifest = require('./nginx-deployment.json');

async function cleanup(client) {
  try {
    await client.apis.apps.v1.namespaces('default').deployments(deploymentManifest.metadata.name).delete();
  } catch (err) {
    console.warn(`Unable to delete deployment ${ deploymentManifest.metadata.name }.  Skipping.`);
  }
}

async function triggerEvents(client) {
  //
  // Trigger some events
  //
  for (let count = 0; count < 3; count++) {
    await new Promise(resolve => setTimeout(resolve, 1000));
    await client.apis.apps.v1.namespaces('default').deployments.post({ body: deploymentManifest });
    await new Promise(resolve => setTimeout(resolve, 1000));
    await cleanup(client);
  }
}

async function main() {
  try {
    const client = new Client({ config: config.fromKubeconfig(), version: '1.9' });

    //
    // Clean up our cluster and get ready to trigger events.
    //
    await cleanup(client);

    //
    // Get a JSON stream for Deployment events
    //
    const stream = client.apis.apps.v1beta.watch.namespaces('default').deployments.getStream();
    const jsonStream = new JSONStream();
    stream.pipe(jsonStream);
    jsonStream.on('data', object => {
      console.log('Event: ', JSON.stringify(object, null, 2));
    });

    //
    // Cause Events to be written to `jsonStream`
    //
    await triggerEvents(client);

    //
    // Disconnect from the watch endpoint
    //
    stream.abort();
  } catch (err) {
    console.error('Error: ', err);
  }
}

main();