Non-root Parity Docker container unable to use volumes

[thodges-gh]

• Parity Ethereum version: v2.0.9-stable-09f7757-20181028
• Operating system: Linux host running Docker container
• Installation: Docker :stable tag
• Fully synchronized: n/a
• Network: n/a
• Restarted: yes

I noticed this issue on the :stable Docker tag recently. The Parity container is unable to write to a volume created with docker volume create when using --base-path or --db-path.

Steps to reproduce

Pull the latest :stable Docker tag:

docker pull parity/parity:stable

Create the Docker volume:

docker volume create --name parity-test

Run the Parity Docker container using the new volume:

docker run -p 8546:8546 -v parity-test:/data \
            -it parity/parity:stable --chain ropsten \
           --ws-interface all --ws-origins "all" \
           --base-path /data

Observe returned error:

Error upgrading parity data: CannotCreateConfigPath

Expected behavior

This may just be a simple documentation fix, but the expected behavior is a docker run command that can utilize the volume created by Docker. The existing Docker documentation may need an update anyway.

[jam10o-new]

Hey, I agree that this might need an emergency documentation change. Parity doesn't run as the root user in docker anymore, so any volumes need to be mounted or chowned to the parity user/uid 1000.

For some background, here's why:
#9689

(I'll leave this open to remind myself to actually update the docker wiki page asap 😅)

[levino]

I posted a working docker-compose file which also works in docker swarm.