CODEWITHSUNDEEP
dockerdocker-compose
cscan
cscan

Reputation: 3850

Docker Compose - container receiving connection refused

Using docker-compose, I'm trying to run my API on a publicly available port 8080 and an sqs service on a privately available port 9324. The API needs to be able to communicate with the sqs service. In order to do so, I have set up the following docker-compose.yml:

version: '2'
services:
  api:
    image: api
    ports:
      - "8080:8080"
  sqs:
    image: pakohan/elasticmq

I have tried several iterations, including adding a link alias for the api:

links:
  - "sqs:localhost"

and exposing the port for sqs:

ports:
  - "9324:9324"

but neither seems to work. The API always gets a connection refused error when trying to communicate with the sqs service.

When the sqs port is publicly exposed an API running outside of docker is able to communicate just fine (so the sqs service is getting initialized properly).

Does anyone have any ideas as to how to solve this problem?

Upvotes: 14

Views: 30451

Answers (2)

user3681304
user3681304

Reputation: 729

Please note that links is a legacy feature of Docker now (see Docs).

When you declare multiple services within a single docker-compose file, they will actually be inside the same network (be it the default one or a user-defined one). The trick then is to use the name of your service rather than localhost. With your original example then:

version: '2'
services:
  api:
    image: api
    ports:
      - "8080:8080"
  sqs:
    image: pakohan/elasticmq

You simply need to make sure you're accessing sqs rather than localhost (your hostname for the sqs service should literally be: sqs)

Upvotes: 16

jwodder
jwodder

Reputation: 57630

Trying to trick the api container into connecting to sqs by telling it that it's actually connecting to localhost isn't going to work. You need to make sqs available to api under a name that doesn't already have a special meaning, like:

links:
    - sqs:original-name

or even:

links:
    - sqs

which makes sqs accessible to api under the name "sqs".

Then, of course, you need to tell api that it should connect to port 9324 of original-name or sqs instead of port 9324 of localhost. How you do that depends on what api actually is.

Upvotes: 9

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