Example of creating a Docker data volume, exporting it, and re-importing it to a completely fresh container

DockerRedis_ExportImport_Dump.sh

# Create the container - we run 'echo' in the container, and reuse the same as we will be running later
docker run -d -v /data --name redis.data dockerfile/redis echo Data-only container for Redis
# the data container doesn't show up  - nothing is running
docker ps      
# will show 'redis.data', but as stopped
docker ps -a   

# start redis, attach to 'redis.data'
docker run -d -p 6379:6379 --volumes-from redis.data --name ca.redis.1 dockerfile/redis

docker ps    # shows as running
redis-cli ping
#> PONG

redis-cli set alister hello
#> OK
redis-cli get alister
#> "hello"
redis-cli save
> OK
docker stop ca.redis.1
# Now, we destroyed the running Redis

########################  


# Pull the data out of the data-container
# -rm: remove the container when it exits
# --volumes-from DATA: attach to the volumes shared by the DATA container
# -v $(pwd):/backup: bind mount the current directory into the container; to write the tar file to
# busybox: a small simpler image - good for quick maintenance
# tar cvf /backup/ca.redis.dump.tar /data: creates an uncompressed tar file of all the files in the /data directory

docker run --rm --volumes-from redis.data -v $(pwd):/backup busybox tar cvf /backup/ca.redis.dump.tar /data

# kill all the containers we have - we will rebuild from 'ca.redis.dump.tar'
docker ps -a
# get the container IDs that make up redis.data & ca.redis.1 
#docker stop ....
#docker rm   ....
# now the list shoudl be empty (of redis-related containers)
docker ps -a

### 

# OK, so we are back at nothing, but we have a ca.redis.dump.tar file with a /data/dump.rdb file in it.

# Recreate the container - we only run 'echo' in the container, and reuse the same as we will be running
docker run -d -v /data --name ca.redis-dumps dockerfile/redis echo "Data-only container for Redis"

# data should not be there yet
docker run --rm --volumes-from ca.redis-dumps busybox ls -l  /data

# put the data into the container from the backup
docker run --rm --volumes-from ca.redis-dumps -v $(pwd):/backup busybox tar xvf /backup/ca.redis.dump.tar

# verify it is there now
docker run --rm --volumes-from ca.redis-dumps busybox ls -l  /data
# should show data/ & data/dump.rdb


# Now we run the redis container, with access to the /data/ directory
docker run -d -p 6379:6379 --volumes-from ca.redis-dumps --name ca.redis.8 dockerfile/redis

# and we see what is now in redis
redis-cli KEYS \*
#>  "alister"
redis-cli get alister
#> "hello"

# It worked. We created/saved the contents of a data container, and then brought it back, via a tarball.