Local mongo replicaset running mongo:4.2-bionic for development using docker-compose.
Switch to the directory of the version you want, and run:
docker-compose up
This should bring up 3 containers of mongodb, running a replicaset called rs0.
If you wish to switch versions, make sure you clean up first:
docker-compose stop
docker-compose rm
In your main application, you need to adjust your docker-compose in order for your application to be able to connect to the mongo containers. Use the below template of docker-compose.yml:
version: "3"
services:
app:
build: .
networks:
- default
- localmongo
external_links:
- localmongo1:mongo1
- localmongo2:mongo2
- localmongo3:mongo3
networks:
localmongo:
external:
name: localmongo_default
Assuming you clone this repo into a folder called localmongo, upon running docker-compose, docker will create a network called localmongo_default. You can view this by running docker network ls, and also by inspecting docker inspect localmongo1.
In the application's docker-compose.yml, we are specifying that the app must join 2 networks: the default one, as well as localmongo network, which is declared at the end of the file, pointing to an external network localmongo_default.
To troubleshoot connectivity issues, do docker exec -it <appContainerID> bash into your application container and look at cat /etc/hosts. You should see 2 entries for the container, one per network. You should be able to do ping mongo1.
If it does not work, do docker inspect <appContainerID> and proceed from there. To clean up networks, use with care: docker network prune
Checkout the documentation of docker-compose networking.
Kira Layto for their Stack Overflow code snippet.