Netlify build logging with Datadog

Netlify's build plugins allow us to to perform a variety of custom build/deploy related tasks. One such task might be to log deployment status in Datadog for analysis. Thankfully this is easy using agent-less logging.

Here's what a simple log plugin might look like.

const createLogger = require('./logger');

module.exports = {
  onSuccess: async ({ inputs: { service } }) => {
    const logger = createLogger({ service });
    logger.info('Deploy successful');
    await logger.send();
  },

  onError: async ({ inputs: { service } }) => {
    let logger = createLogger({ service });
    logger.info('Deploy failed');
    await logger.send();
  },
};

And below, a logger implementation using Winston.

const {
  env: { DATADOG_API_KEY, VERSON, ENVIRONMENT },
} = require('process');

function createLogger({ service }) {
  const { createLogger, format, transports } = require('winston');
  const queryString = require('query-string');
  const { combine, json, timestamp } = format;

  const query = queryString.stringify(
    {
      ddsource: `nodejs`,
      service,
      ddtags: [`env:${ENVIRONMENT)}`, `releaseVersion:${VERSON)}`],
    },
    { arrayFormat: 'comma' },
  );

  const httpTransportOptions = {
    host: 'http-intake.logs.datadoghq.com',
    path: `/v1/input/${DATADOG_API_KEY}?${query}`,
    format: combine(timestamp(), json()),
    ssl: true,
  };

  const logger = createLogger({
    level: 'info',
    exitOnError: false,
    transports: [new transports.Http(httpTransportOptions)],
  });

  return {
    info: (...args) => logger.info(...args),
    send: () => {
      const completePromise = new Promise((resolve) => {
        logger.on('finish', () => {
          clearTimeout(timeout);
          console.log(`Successfully sent logs to Datadog`);
          resolve(true);
        });
      });

      logger.end();
      return completePromise;
    },
  };
}