Hey there, let's get that DynamoDB Local container up and running smoothly! The error you're hitting boils down to one simple rule: Docker requires container-side volume mount paths to be absolute, and your Dockerfile is using a relative path that Docker can't resolve.

The Root Cause #

In your Dockerfile, the line VOLUME ["./db"] is causing the issue. Docker doesn't accept relative paths for volume mounts inside containers—this is exactly why you're seeing the invalid mount path: 'db' mount path must be absolute message.

The Fix #

Update your Dockerfile to use an absolute path for the VOLUME directive. Since you've set WORKDIR /home/dynamodblocal, your ./db directory lives at /home/dynamodblocal/db inside the container. Here's the corrected Dockerfile:

FROM amazon/dynamodb-local
WORKDIR /home/dynamodblocal
RUN mkdir ./db && chown -R 1000 ./db
CMD ["-jar", "DynamoDBLocal.jar", "-dbPath", "./db", "-sharedDb"]
VOLUME ["/home/dynamodblocal/db"]

Why This Works #

• The VOLUME directive now points to an absolute path inside the container, which Docker recognizes as a valid mount point.
• Your CMD still uses ./db for -dbPath—that's totally fine! It’s relative to the WORKDIR you set, so DynamoDB will still find the correct database directory.
• Your docker-compose.yml is already configured correctly: it maps the dynamodb-local named volume to /home/dynamodblocal/db, which matches the updated VOLUME path perfectly.

Next Steps #

Run this command to rebuild and restart your containers:

docker-compose up --build

This should eliminate the volume path error, and your DynamoDB Local container should start up without issues.

内容的提问来源于stack exchange，提问作者Prasenjit