Mount a volume in docker-compose conditionally
Since extend
has been removed in version 3 there's a new way of overriding settings by providing multiple -f params where the next file extends the previous config
The docs are mixed between versions https://docs.docker.com/compose/extends/#multiple-compose-files
i.e. to run in development mode
docker-compose -f docker-compose.yml -f docker-compose.dev.yml
Where docker-compose.yml
contains the full config and docker-compose.dev.yml
only adds a volume
services: serviceA: volumes: -.:/usr/local/abc/service
Instead of (not) mounting a volume commenting out that line, I would use https://docs.docker.com/compose/extends/#example-use-case to run a service extension that specifies a volume.
I do this to tackle two different problems:
- I don't specify a volume when the docker image is meant to run in production and has all the necessary files bundled in it.
- I specify a volume during development, to check live changes.
Let's say that the .war filename is "app.war"... you could overwrite it using a env variable like this:
volumes: - ./application/webapps/${APPLICATION_ENV}.war:/usr/local/tomcat/webapps/app.war
Then when you need to run a different war file just change the APPPLICATION_ENV
value to the one you need to run and restart the container.
I don't think docker-compose
does have "conditional volumes", but that way you could change the app.war according with your environment.
Other way would be running a script after the docker-compose up/start
to overwrite it, and do it only when needed, like:
docker-compose exec your-container-name cp /a/volume/path/app.war /usr/local/tomcat/webapps/app.war