How to restore a mongo Docker container on the Mac

I removed my mongo container

docker rm myMongoDB

Did I lose all my data, or I can restore it? If so, how?

When I try to run another container from the image

docker run -p 27017:27017 -d mongo --name myMongo2

it won't run and its STATUS says Exited (2) 8 seconds ago.

Solution

The official mongo image on Docker Hub (https://hub.docker.com/_/mongo/) defines two volumes to store data in the Dockerfile. If you did not explicitly specify a -v / --volume option when running the container, Docker created anonymous (unnamed) volumes for those, and those volumes may still be around. It may be a bit difficult to find which volumes were last used by the container, because they don't have a name.

To list all volumes that are still present on the docker host, use;

docker volume ls

Which should give you something like this;

DRIVER              VOLUME NAME
local               9142c58ad5ac6d6e40ccd84096605f5393bf44ab7b5fe51edfa23cd1f8e13e4b
local               4ac8e34c11ac7955b9b79af10c113b870edd0869889d1005ee17e98e7c6c05f1
local               da0b4a7a00c4b60c492599dabe1dbc501113ae4b2dd1811527384a5dc26cab13
local               81a40483ae00d72dcfa2117b3ae40f3fe79038544253e60b85a8d0efc8f3d139

To see what's in a volume, you can attach it to a temporary container, and check what's in there. For example;

docker run -it -v 81a40483ae00d72dcfa2117b3ae40f3fe79038544253e60b85a8d0efc8f3d139:/volume-data ubuntu

That will start an interactive shell in a new ubuntu container, with the volume 81a40483ae00d72dcfa2117b3ae40f3fe79038544253e60b85a8d0efc8f3d139 mounted at /volume-data/ inside the container.

You can then go into that directory, and check if it's the volume you're looking for:

root@08c11a34ed44:/# cd /volume-data/
root@08c11a34ed44:/volume-data# ls -la

once you identified which volumes (according to the Dockerfile, the mongo image uses two), you can start a new mongo container, and mount those volumes;

docker run -d --name mymongo \
  -v 4ac8e34c11ac7955b9b79af10c113b870edd0869889d1005ee17e98e7c6c05f1:/data/db/ \
  -v  da0b4a7a00c4b60c492599dabe1dbc501113ae4b2dd1811527384a5dc26cab13:/data/configdb/ \
  mongo

I really suggest you read the Where to Store Data section in the documentation for the mongo image on Docker Hub to prevent loosing your data.

NOTE

I also noted that your last command puts the --name myMongo2 after the image name; it should be before mongo (the image name). Also myMongo2 is an invalid container name, as it is not allowed to have uppercase characters.