nickadam/docker-volume-cp repository overview

⁠nickadam/docker-volume-cp:v1.0.0

This image was created to simplify moving production services between docker systems.

⁠Example usage

Look at docker-compose.yml for an example of how this works.

example-service and example-service2 each write data to their respective volumes. The path to one of the volumes contains a space to demonstrate how to handle paths with spaces.

sync-sender shares the same volumes and paths as the two example services. The target paths between the service and the sender don't need to be same. The command given to sync-sender initiates the sync process, let's break it down.

sync sync-receiver 22 /data/ "/root/my data/"

• sync merely indicates this container is not receiving data but sending it.
• sync-receiver is the name of the receiving server. If we were syncing between different docker servers, we could use an IP or remote hostname here.
• 22 is the remote port to connect to. Notice the comments where port 3000 is used
• All arguments from this point forward are directories to sync and you can specify as many as you need.
• /data/ a path to a volume to sync. Notice the trailing slash. This is required since there is already a /data directory on the receiving server. If we didn't have the slash files would end up in /data/data on the receiving server.
• "/root/my data/" another path to a volume to sync using double quotes for spaces.

sync-receiver uses this same image but it doesn't have a command specified so it just launches sshd and waits for connections.

sync-sender will continually rerun rsync with 5 second pauses between executions. The detailed log from rsync is in the container's /sync.log.

⁠Warnings

• The credentials to connect to nickadam/docker-volume-cp:v1.0.0 are baked in the image and are therefore publicly known by all. Don't use this service over an untrusted environment.
• Syncing will delete files in the target volume. Be very careful not to mix the sender and receiver container volumes. Doing so will destroy all your data.