serverless/lib/plugins/aws/lib/validate.js

'use strict';

const BbPromise = require('bluebird');
const chalk = require('chalk');

module.exports = {
  validate() {
    if (!this.serverless.config.servicePath) {
      const error = new this.serverless.classes.Error(
        'This command can only be run inside a service directory'
      );
      return BbPromise.reject(error);
    }

    this.options.stage = this.provider.getStage();
    this.options.region = this.provider.getRegion();

    if (
      !['logs', 'info', 'deploy', 'remove', 'rollback', 'metrics', 'invoke'].includes(
        this.serverless.processedInput.commands[0]
      ) ||
      this.serverless.processedInput.commands[1] === 'local'
    ) {
      return BbPromise.resolve();
    }
    const creds = Object.assign({}, this.provider.getCredentials());
    delete creds.region;
    delete creds.signatureVersion;

    if (
      Object.keys(creds).length === 0 &&
      !(process.env.AWS_WEB_IDENTITY_TOKEN_FILE && process.env.AWS_ROLE_ARN) &&
      !process.env.ECS_CONTAINER_METADATA_FILE &&
      !process.env.AWS_CONTAINER_CREDENTIALS_RELATIVE_URI &&
      !process.env.AWS_CONTAINER_CREDENTIALS_FULL_URI
    ) {
      // first check if the EC2 Metadata Service has creds before throwing error
      const ec2Credentials = new this.provider.sdk.EC2MetadataCredentials({
        httpOptions: { timeout: 5000 }, // 5 second timeout
        maxRetries: 0, // retry 0 times
      });
      return new BbPromise((resolve, reject) =>
        ec2Credentials.load(err => {
          if (err) {
            const message = [
              'AWS provider credentials not found.',
              ' Learn how to set up AWS provider credentials',
              ` in our docs here: <${chalk.green('http://slss.io/aws-creds-setup')}>.`,
            ].join('');
            reject(new this.serverless.classes.Error(message));
          } else {
            resolve({});
          }
        })
      );
    }
    return BbPromise.resolve();
  },
};