serverless-plugin-flambe/src/hooks/deploy.js

Eliminates lambda cold starts

const { oneOf, get } = require('../utils/lodash');
const log = require('../utils/log');
const { DELEGATE_LAMBDA_NAME, REGION_PATHS } = require('../flambe.config');

module.exports = async (ctx) => {
  const rates = Object.keys(ctx.rates);

  const credentials = ctx.serverless.providers.aws.getCredentials();
  credentials.region = oneOf(ctx, REGION_PATHS);

  ctx.serverless.providers.aws.sdk.config.update({ maxRetries: 20 });
  const lambda = new ctx.serverless.providers.aws.sdk.Lambda(credentials);

  const invoke = async (rate) => {
    try {
      await lambda
        .invoke({
          FunctionName: get(ctx, DELEGATE_LAMBDA_NAME),
          InvocationType: 'Event',
          Payload: JSON.stringify({ rate }),
        })
        .promise();
    } catch (e) {
      console.log('Error igniting resource', e.message);
    }
  };

  if (rates.length > 0) {
    log('Igniting sources');
  }
  await Promise.all(rates.map(invoke));
};