Simple rsync container based on alpine

A simple rsync server/client Docker image to easily rsync data within Docker volumes

Simple Usage

Get files from remote server within a docker volume:

$ docker run --rm -v blobstorage:/data/ eeacms/rsync \
         rsync -avzx --numeric-ids [email protected]:/var/local/blobs/ /data/

Get files from remote server to a data container:

$ docker run -d --name data -v /data busybox
$ docker run --rm --volumes-from=data eeacms/rsync \
         rsync -avz [email protected]:/var/local/blobs/ /data/

Advanced Usage

Client setup

Start client to pack and sync every night:

$ docker run --name=rsync_client -v client_vol_to_sync:/data \
             -e CRON_TASK_1="0 1 * * * /data/pack-db.sh" \
             -e CRON_TASK_2="0 3 * * * rsync -e 'ssh -p 2222' -aqx --numeric-ids [email protected]:/data/ /data/" \
         eeacms/rsync client

Copy the client SSH public key printed found in console

SSH key persistence - client

To use the same generated keys on docker container re-creation, you need to persist the key directory ( /root/.ssh ) in a Docker volume. On first start the keys will be created, and then, on all subsequent starts they will be re-used.

For example, you can use a volume called ssh-key like this:

$ docker run --name=rsync_client -v ssh-key:/root/.ssh -v client_vol_to_sync:/data
         eeacms/rsync client

SSH key persistence - server

To use the same generated host keys on docker container re-creation, you need to persist the host key directory ( /ssh_host_keys ) in a Docker volume. On first start the keys will be created, and then, on all subsequent starts they will be re-used.

$ docker run --name=rsync_server -v ssh-host-keys:/ssh_host_keys -v server_vol_to_sync:/data
         eeacms/rsync server

If you want the rsync client to skip checking the ssh host keys, you can always add this 2 parameters to your client ssh configuration -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no

Server setup

Start server on foo.bar.com

# docker run --name=rsync_server -d -p 2222:22 -v ssh-host-keys:/ssh_host_keys -v server_vol_to_sync:/data \
             -e SSH_AUTH_KEY_1="<SSH KEY FROM rsync_client>" \
             -e SSH_AUTH_KEY_n="<SSH KEY FROM rsync_client_n>" \
         eeacms/rsync server

Verify that it works

Add test file on server:

$ docker exec -it rsync_server sh
  $ touch /data/test

Bring the file on client:

$ docker exec -it rsync_client sh
  $ rsync -e 'ssh -p 2222' -avz [email protected]:/data/ /data/
  $ ls -l /data/

Rsync data between containers in Rancher

0. Request TCP access to port 2222 to an accessible server of environment of the new installation from the source container host server.

1. Start rsync client on host from where do you want to migrate data (ex. production).

   Infrastructures -> Hosts -> Add Container

   • Select image: eeacms/rsync
   • Command: sh
   • Volumes -> Volumes from: Select source container

2. Open logs from container, copy the ssh key from the message

3. Start rsync server on host from where do you want to migrate data (ex. devel). The destination container should be temporarily moved to an accessible server ( if it's not on one ) .

   Infrastructures -> Hosts -> Add Container

   • Select image: eeacms/rsync
   • Port map -> +(add) : 2222:22
   • Command: server
   • Add environment variable: SSH_AUTH_KEY=""
   • Volumes -> Volumes from: Select destination container

4. Within rsync client container from step 1 run:

  $ rsync -e 'ssh -p 2222' -avz <SOURCE_DUMP_LOCATION> root@<TARGET_HOST_IP_ON_DEVEL>:<DESTINATION_LOCATION>

4. The rsync servers can be deleted, and the destination container can be moved back ( if needed )