Add docker managed volumes

[myspotontheweb]

The main issue I have with using local directories for container persistence is that

1. Files created are owned by root.
2. The files are typically binary and not editable or interesting to a programmer in any way
3. Random "data" directories just a bit ugly in the filesystem :-(

I have discovered that docker-compose can hand-off the management of volumes to the docker engine instead. For example after running the examples associated with this PR, you can see that Docker has created 3 volumes:

$ docker volume list
DRIVER              VOLUME NAME
local               mongo_dbdata
local               mysql_dbdata
local               postgres_dbdata

To conclude I like how this approach elegantly hides away the messy details of persistence. Easy to cleanup the volume used by passing the "-v" option

docker-compose down -v

[kodemaan]

Just curious would all these different database engines sharing the same volume cause any issues? I'm sure they use a different folder structure but might be worth looking into

[myspotontheweb]

They don't share the same volume. If you use Docker to list the volumes you'll see each project creates a volume called projectname_dbdata

$ docker volume list
DRIVER              VOLUME NAME
local               mongo_dbdata
local               mysql_dbdata
local               postgres_dbdata

[kodemaan]

They don't share the same volume. If you use Docker to list the volumes you'll see each project creates a volume called projectname_dbdata

$ docker volume list
DRIVER              VOLUME NAME
local               mongo_dbdata
local               mysql_dbdata
local               postgres_dbdata

Alright didn't know that cool :)

[alexmacarthur]

A welcome improvement! I had been relatively unfamiliar with managed volumes -- I see the benefits over clogging up the filesystem with data directories.

[alexmacarthur]

Good call. 👍