How to persist data in a dockerized DynamoDB using volumes

Question

My docker compose file has two containers and looks like this

  version: \'3\'

  services:
     dynamodb:
       image: amazon/dynamodb-local
       ports: 
            


        

Answer 1

So that image use by default in-memory dynamodb (what you can find by running docker inspect on that image)

"CMD [\"-jar\" \"DynamoDBLocal.jar\" \"-inMemory\"]"

So if you want to keep your data you need to do something like this in you docker-compose:

version: '3'

volumes: 
  dynamodb_data:

services:
  dynamodb:
    image: amazon/dynamodb-local
    command: -jar DynamoDBLocal.jar -sharedDb -dbPath /home/dynamodblocal/data/
    volumes:
     - dynamodb_data:/home/dynamodblocal/data
    ports:
     - "8000:8000"

Answer 2

To preserve data across docker installations create volume using docker.

docker volume create --driver local --opt type=none \
    --opt device=/var/opt/dynamodb_data --opt o=bind dynamodb_data

use external option:

version: "3"
volumes: 
  dynamodb_data:
    external: true
services:
  dynamodb-local:
    image: amazon/dynamodb-local
    command: ["-jar", "DynamoDBLocal.jar", "-sharedDb", "-dbPath", "/home/dynamodblocal/data"]
    volumes:
      - dynamodb_data:/home/dynamodblocal/data

Answer 3

You can try this docker-compose config:

version: '3'

volumes: 
  dynamodb_data:

services:
  dynamodb:
    image: amazon/dynamodb-local
    command: -jar DynamoDBLocal.jar -sharedDb -dbPath /home/dynamodblocal
    volumes:
     - dynamodb_data:/home/dynamodblocal
    ports:
     - "8000:8000"