TimeMachine on Samba for Docker

In this repo you will find instructions and resources on how to run a Docker container with Samba 4 to support Apple's TimeMachine. You will also be able to build your own Docker image if you don't want to use the pre-built one.

Features:

Alpine Linux based.
Avahi discovery service configured.
Configuration options:
- Group name & ID
- User name & ID
- Samba user password
- Limit storage size

How to run the container

Via `docker run`

docker run -d --net=host \
            --volume /opt/timemachine:/timemachine/ \
            --volume /etc/localtime:/etc/localtime:ro \
            -e TM_PWD=notsosecretpassword \
            --restart=always \
            --name=timemachine default50/timemachinesambadocker

For more information about the options for docker run visit https://docs.docker.com/engine/reference/run/

Via `docker-compose`

You can modify the parameters in the sample docker-compose.sample.yml file to suit your needs and then rename it to docker-compose.yml. To launch the service container just do docker-compose up -d in the same directory of of the composer file.

Note: you may need to install compose. Check https://docs.docker.com/compose/install/

Environment variables

This is a summary of the environment variables that can be used to override any of the default values.

Variable	Function	Default.
TM_USER	POSIX user name inside container	timemachine
TM_GROUP	POSIX group name inside container	timemachine
TM_UID	POSIX user ID inside container	1000
TM_GID	POSIX group ID inside container	1000
TM_PWD	Samba password	timemachine
TM_SIZE	Time Machine storage size limit (MB)	512000

How to build your own image

You can always build your own image instead of using the image provided through my public repository.

It's as simple as doing docker build . in the root of the repository, but it's better if you tag the image with something like this:

docker build --tag default50/timemachinesambadocker .

Advanced

It is important to note that the files that Samba will create in the volume that you specify will have the same file UID and GID that you set as TM_UID and TM_GID. This is only relevant if you run this container as an unprivileged user and you want the files to be accessible by that same user.

Alpine's busybox package does not support UID/GIDs higher than 256000 (see this StackOverflow post), that's why I'm using the shadow package here.

Credits

The contents here were mostly obtained from willtho89/docker-samba-timemachine's repository with some improvements.

And according to willtho89's own words:

It's mostly based on u/KervyN's HowTo and dperson's Samba docker container.

default50/TimeMachineSambaDocker