Pipelines intermittently fails to connect to defined Mongo service

[Rob Wilson]

In our pipeline we have two defined services, MongoDB and Redis.

Our first step is our backend tests which interact with both these services.

Approximately 20% of the time the step fails with: `MongoError: failed to connect to server [localhost:27017] on first connect` and I have to manually re-run the failed step.

In the screenshot below, multiple tests had already passed which created and closed connections to Mongo, only for it to fail later on. Other times it fails immediately.

pipelines:
  default:
    - step:
      name: Server Test
      image: <redacted>
      script:
        - cd express
        - echo $dotenv | base64 -d > .env
        - npm install
        - npm test
      services:
        - mongo
        - redis
    - <other steps redacted>
definitions:
  services:
    mongo:
      image: mongo
    redis:
      image: redis

Has anyone else come accross this issue? 

[Peter Plewa]

Hi @Rob Wilson

Could you upload full logs for both your mongo service and script? 

If mongo successfully starts all the time it looks like a race condition that you may be able to workaround by either adding additional checks in your script to see if it's up or adding delays.

Thanks,
Peter